build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>
This commit is contained in:
Niels de Vos
2025-03-04 08:57:28 +01:00
committed by mergify[bot]
parent 15da101b1b
commit bec6090996
8047 changed files with 1407827 additions and 3453 deletions

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Apache License
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TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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"License" shall mean the terms and conditions for use, reproduction,
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form, that is based on (or derived from) the Work and for which the
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"Contribution" shall mean any work of authorship, including
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to that Work or Derivative Works thereof, that is intentionally
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or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
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5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
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this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
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7. Disclaimer of Warranty. Unless required by applicable law or
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unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
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work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
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the Work or Derivative Works thereof, You may choose to offer,
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on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
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To apply the Apache License to your work, attach the following
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e2e/vendor/github.com/prometheus/client_golang/NOTICE generated vendored Normal file
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Prometheus instrumentation library for Go applications
Copyright 2012-2015 The Prometheus Authors
This product includes software developed at
SoundCloud Ltd. (http://soundcloud.com/).
The following components are included in this product:
perks - a fork of https://github.com/bmizerany/perks
https://github.com/beorn7/perks
Copyright 2013-2015 Blake Mizerany, Björn Rabenstein
See https://github.com/beorn7/perks/blob/master/README.md for license details.
Go support for Protocol Buffers - Google's data interchange format
http://github.com/golang/protobuf/
Copyright 2010 The Go Authors
See source code for license details.

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Copyright (c) 2013 The Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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// Copyright 2013 The Go Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd.
// Package header provides functions for parsing HTTP headers.
package header
import (
"net/http"
"strings"
)
// Octet types from RFC 2616.
var octetTypes [256]octetType
type octetType byte
const (
isToken octetType = 1 << iota
isSpace
)
func init() {
// OCTET = <any 8-bit sequence of data>
// CHAR = <any US-ASCII character (octets 0 - 127)>
// CTL = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
// CR = <US-ASCII CR, carriage return (13)>
// LF = <US-ASCII LF, linefeed (10)>
// SP = <US-ASCII SP, space (32)>
// HT = <US-ASCII HT, horizontal-tab (9)>
// <"> = <US-ASCII double-quote mark (34)>
// CRLF = CR LF
// LWS = [CRLF] 1*( SP | HT )
// TEXT = <any OCTET except CTLs, but including LWS>
// separators = "(" | ")" | "<" | ">" | "@" | "," | ";" | ":" | "\" | <">
// | "/" | "[" | "]" | "?" | "=" | "{" | "}" | SP | HT
// token = 1*<any CHAR except CTLs or separators>
// qdtext = <any TEXT except <">>
for c := 0; c < 256; c++ {
var t octetType
isCtl := c <= 31 || c == 127
isChar := 0 <= c && c <= 127
isSeparator := strings.ContainsRune(" \t\"(),/:;<=>?@[]\\{}", rune(c))
if strings.ContainsRune(" \t\r\n", rune(c)) {
t |= isSpace
}
if isChar && !isCtl && !isSeparator {
t |= isToken
}
octetTypes[c] = t
}
}
// AcceptSpec describes an Accept* header.
type AcceptSpec struct {
Value string
Q float64
}
// ParseAccept parses Accept* headers.
func ParseAccept(header http.Header, key string) (specs []AcceptSpec) {
loop:
for _, s := range header[key] {
for {
var spec AcceptSpec
spec.Value, s = expectTokenSlash(s)
if spec.Value == "" {
continue loop
}
spec.Q = 1.0
s = skipSpace(s)
if strings.HasPrefix(s, ";") {
s = skipSpace(s[1:])
if !strings.HasPrefix(s, "q=") {
continue loop
}
spec.Q, s = expectQuality(s[2:])
if spec.Q < 0.0 {
continue loop
}
}
specs = append(specs, spec)
s = skipSpace(s)
if !strings.HasPrefix(s, ",") {
continue loop
}
s = skipSpace(s[1:])
}
}
return
}
func skipSpace(s string) (rest string) {
i := 0
for ; i < len(s); i++ {
if octetTypes[s[i]]&isSpace == 0 {
break
}
}
return s[i:]
}
func expectTokenSlash(s string) (token, rest string) {
i := 0
for ; i < len(s); i++ {
b := s[i]
if (octetTypes[b]&isToken == 0) && b != '/' {
break
}
}
return s[:i], s[i:]
}
func expectQuality(s string) (q float64, rest string) {
switch {
case len(s) == 0:
return -1, ""
case s[0] == '0':
q = 0
case s[0] == '1':
q = 1
default:
return -1, ""
}
s = s[1:]
if !strings.HasPrefix(s, ".") {
return q, s
}
s = s[1:]
i := 0
n := 0
d := 1
for ; i < len(s); i++ {
b := s[i]
if b < '0' || b > '9' {
break
}
n = n*10 + int(b) - '0'
d *= 10
}
return q + float64(n)/float64(d), s[i:]
}

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// Copyright 2013 The Go Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd.
package httputil
import (
"net/http"
"github.com/prometheus/client_golang/internal/github.com/golang/gddo/httputil/header"
)
// NegotiateContentEncoding returns the best offered content encoding for the
// request's Accept-Encoding header. If two offers match with equal weight and
// then the offer earlier in the list is preferred. If no offers are
// acceptable, then "" is returned.
func NegotiateContentEncoding(r *http.Request, offers []string) string {
bestOffer := "identity"
bestQ := -1.0
specs := header.ParseAccept(r.Header, "Accept-Encoding")
for _, offer := range offers {
for _, spec := range specs {
if spec.Q > bestQ &&
(spec.Value == "*" || spec.Value == offer) {
bestQ = spec.Q
bestOffer = offer
}
}
}
if bestQ == 0 {
bestOffer = ""
}
return bestOffer
}

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command-line-arguments.test

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See [![Go Reference](https://pkg.go.dev/badge/github.com/prometheus/client_golang/prometheus.svg)](https://pkg.go.dev/github.com/prometheus/client_golang/prometheus).

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"math"
"sync/atomic"
"time"
)
// atomicUpdateFloat atomically updates the float64 value pointed to by bits
// using the provided updateFunc, with an exponential backoff on contention.
func atomicUpdateFloat(bits *uint64, updateFunc func(float64) float64) {
const (
// both numbers are derived from empirical observations
// documented in this PR: https://github.com/prometheus/client_golang/pull/1661
maxBackoff = 320 * time.Millisecond
initialBackoff = 10 * time.Millisecond
)
backoff := initialBackoff
for {
loadedBits := atomic.LoadUint64(bits)
oldFloat := math.Float64frombits(loadedBits)
newFloat := updateFunc(oldFloat)
newBits := math.Float64bits(newFloat)
if atomic.CompareAndSwapUint64(bits, loadedBits, newBits) {
break
} else {
// Exponential backoff with sleep and cap to avoid infinite wait
time.Sleep(backoff)
backoff *= 2
if backoff > maxBackoff {
backoff = maxBackoff
}
}
}
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import "runtime/debug"
// NewBuildInfoCollector is the obsolete version of collectors.NewBuildInfoCollector.
// See there for documentation.
//
// Deprecated: Use collectors.NewBuildInfoCollector instead.
func NewBuildInfoCollector() Collector {
path, version, sum := "unknown", "unknown", "unknown"
if bi, ok := debug.ReadBuildInfo(); ok {
path = bi.Main.Path
version = bi.Main.Version
sum = bi.Main.Sum
}
c := &selfCollector{MustNewConstMetric(
NewDesc(
"go_build_info",
"Build information about the main Go module.",
nil, Labels{"path": path, "version": version, "checksum": sum},
),
GaugeValue, 1)}
c.init(c.self)
return c
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// Collector is the interface implemented by anything that can be used by
// Prometheus to collect metrics. A Collector has to be registered for
// collection. See Registerer.Register.
//
// The stock metrics provided by this package (Gauge, Counter, Summary,
// Histogram, Untyped) are also Collectors (which only ever collect one metric,
// namely itself). An implementer of Collector may, however, collect multiple
// metrics in a coordinated fashion and/or create metrics on the fly. Examples
// for collectors already implemented in this library are the metric vectors
// (i.e. collection of multiple instances of the same Metric but with different
// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
type Collector interface {
// Describe sends the super-set of all possible descriptors of metrics
// collected by this Collector to the provided channel and returns once
// the last descriptor has been sent. The sent descriptors fulfill the
// consistency and uniqueness requirements described in the Desc
// documentation.
//
// It is valid if one and the same Collector sends duplicate
// descriptors. Those duplicates are simply ignored. However, two
// different Collectors must not send duplicate descriptors.
//
// Sending no descriptor at all marks the Collector as “unchecked”,
// i.e. no checks will be performed at registration time, and the
// Collector may yield any Metric it sees fit in its Collect method.
//
// This method idempotently sends the same descriptors throughout the
// lifetime of the Collector. It may be called concurrently and
// therefore must be implemented in a concurrency safe way.
//
// If a Collector encounters an error while executing this method, it
// must send an invalid descriptor (created with NewInvalidDesc) to
// signal the error to the registry.
Describe(chan<- *Desc)
// Collect is called by the Prometheus registry when collecting
// metrics. The implementation sends each collected metric via the
// provided channel and returns once the last metric has been sent. The
// descriptor of each sent metric is one of those returned by Describe
// (unless the Collector is unchecked, see above). Returned metrics that
// share the same descriptor must differ in their variable label
// values.
//
// This method may be called concurrently and must therefore be
// implemented in a concurrency safe way. Blocking occurs at the expense
// of total performance of rendering all registered metrics. Ideally,
// Collector implementations support concurrent readers.
Collect(chan<- Metric)
}
// DescribeByCollect is a helper to implement the Describe method of a custom
// Collector. It collects the metrics from the provided Collector and sends
// their descriptors to the provided channel.
//
// If a Collector collects the same metrics throughout its lifetime, its
// Describe method can simply be implemented as:
//
// func (c customCollector) Describe(ch chan<- *Desc) {
// DescribeByCollect(c, ch)
// }
//
// However, this will not work if the metrics collected change dynamically over
// the lifetime of the Collector in a way that their combined set of descriptors
// changes as well. The shortcut implementation will then violate the contract
// of the Describe method. If a Collector sometimes collects no metrics at all
// (for example vectors like CounterVec, GaugeVec, etc., which only collect
// metrics after a metric with a fully specified label set has been accessed),
// it might even get registered as an unchecked Collector (cf. the Register
// method of the Registerer interface). Hence, only use this shortcut
// implementation of Describe if you are certain to fulfill the contract.
//
// The Collector example demonstrates a use of DescribeByCollect.
func DescribeByCollect(c Collector, descs chan<- *Desc) {
metrics := make(chan Metric)
go func() {
c.Collect(metrics)
close(metrics)
}()
for m := range metrics {
descs <- m.Desc()
}
}
// selfCollector implements Collector for a single Metric so that the Metric
// collects itself. Add it as an anonymous field to a struct that implements
// Metric, and call init with the Metric itself as an argument.
type selfCollector struct {
self Metric
}
// init provides the selfCollector with a reference to the metric it is supposed
// to collect. It is usually called within the factory function to create a
// metric. See example.
func (c *selfCollector) init(self Metric) {
c.self = self
}
// Describe implements Collector.
func (c *selfCollector) Describe(ch chan<- *Desc) {
ch <- c.self.Desc()
}
// Collect implements Collector.
func (c *selfCollector) Collect(ch chan<- Metric) {
ch <- c.self
}
// collectorMetric is a metric that is also a collector.
// Because of selfCollector, most (if not all) Metrics in
// this package are also collectors.
type collectorMetric interface {
Metric
Collector
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package collectors provides implementations of prometheus.Collector to
// conveniently collect process and Go-related metrics.
package collectors
import "github.com/prometheus/client_golang/prometheus"
// NewBuildInfoCollector returns a collector collecting a single metric
// "go_build_info" with the constant value 1 and three labels "path", "version",
// and "checksum". Their label values contain the main module path, version, and
// checksum, respectively. The labels will only have meaningful values if the
// binary is built with Go module support and from source code retrieved from
// the source repository (rather than the local file system). This is usually
// accomplished by building from outside of GOPATH, specifying the full address
// of the main package, e.g. "GO111MODULE=on go run
// github.com/prometheus/client_golang/examples/random". If built without Go
// module support, all label values will be "unknown". If built with Go module
// support but using the source code from the local file system, the "path" will
// be set appropriately, but "checksum" will be empty and "version" will be
// "(devel)".
//
// This collector uses only the build information for the main module. See
// https://github.com/povilasv/prommod for an example of a collector for the
// module dependencies.
func NewBuildInfoCollector() prometheus.Collector {
//nolint:staticcheck // Ignore SA1019 until v2.
return prometheus.NewBuildInfoCollector()
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package collectors
import (
"database/sql"
"github.com/prometheus/client_golang/prometheus"
)
type dbStatsCollector struct {
db *sql.DB
maxOpenConnections *prometheus.Desc
openConnections *prometheus.Desc
inUseConnections *prometheus.Desc
idleConnections *prometheus.Desc
waitCount *prometheus.Desc
waitDuration *prometheus.Desc
maxIdleClosed *prometheus.Desc
maxIdleTimeClosed *prometheus.Desc
maxLifetimeClosed *prometheus.Desc
}
// NewDBStatsCollector returns a collector that exports metrics about the given *sql.DB.
// See https://golang.org/pkg/database/sql/#DBStats for more information on stats.
func NewDBStatsCollector(db *sql.DB, dbName string) prometheus.Collector {
fqName := func(name string) string {
return "go_sql_" + name
}
return &dbStatsCollector{
db: db,
maxOpenConnections: prometheus.NewDesc(
fqName("max_open_connections"),
"Maximum number of open connections to the database.",
nil, prometheus.Labels{"db_name": dbName},
),
openConnections: prometheus.NewDesc(
fqName("open_connections"),
"The number of established connections both in use and idle.",
nil, prometheus.Labels{"db_name": dbName},
),
inUseConnections: prometheus.NewDesc(
fqName("in_use_connections"),
"The number of connections currently in use.",
nil, prometheus.Labels{"db_name": dbName},
),
idleConnections: prometheus.NewDesc(
fqName("idle_connections"),
"The number of idle connections.",
nil, prometheus.Labels{"db_name": dbName},
),
waitCount: prometheus.NewDesc(
fqName("wait_count_total"),
"The total number of connections waited for.",
nil, prometheus.Labels{"db_name": dbName},
),
waitDuration: prometheus.NewDesc(
fqName("wait_duration_seconds_total"),
"The total time blocked waiting for a new connection.",
nil, prometheus.Labels{"db_name": dbName},
),
maxIdleClosed: prometheus.NewDesc(
fqName("max_idle_closed_total"),
"The total number of connections closed due to SetMaxIdleConns.",
nil, prometheus.Labels{"db_name": dbName},
),
maxIdleTimeClosed: prometheus.NewDesc(
fqName("max_idle_time_closed_total"),
"The total number of connections closed due to SetConnMaxIdleTime.",
nil, prometheus.Labels{"db_name": dbName},
),
maxLifetimeClosed: prometheus.NewDesc(
fqName("max_lifetime_closed_total"),
"The total number of connections closed due to SetConnMaxLifetime.",
nil, prometheus.Labels{"db_name": dbName},
),
}
}
// Describe implements Collector.
func (c *dbStatsCollector) Describe(ch chan<- *prometheus.Desc) {
ch <- c.maxOpenConnections
ch <- c.openConnections
ch <- c.inUseConnections
ch <- c.idleConnections
ch <- c.waitCount
ch <- c.waitDuration
ch <- c.maxIdleClosed
ch <- c.maxLifetimeClosed
ch <- c.maxIdleTimeClosed
}
// Collect implements Collector.
func (c *dbStatsCollector) Collect(ch chan<- prometheus.Metric) {
stats := c.db.Stats()
ch <- prometheus.MustNewConstMetric(c.maxOpenConnections, prometheus.GaugeValue, float64(stats.MaxOpenConnections))
ch <- prometheus.MustNewConstMetric(c.openConnections, prometheus.GaugeValue, float64(stats.OpenConnections))
ch <- prometheus.MustNewConstMetric(c.inUseConnections, prometheus.GaugeValue, float64(stats.InUse))
ch <- prometheus.MustNewConstMetric(c.idleConnections, prometheus.GaugeValue, float64(stats.Idle))
ch <- prometheus.MustNewConstMetric(c.waitCount, prometheus.CounterValue, float64(stats.WaitCount))
ch <- prometheus.MustNewConstMetric(c.waitDuration, prometheus.CounterValue, stats.WaitDuration.Seconds())
ch <- prometheus.MustNewConstMetric(c.maxIdleClosed, prometheus.CounterValue, float64(stats.MaxIdleClosed))
ch <- prometheus.MustNewConstMetric(c.maxLifetimeClosed, prometheus.CounterValue, float64(stats.MaxLifetimeClosed))
ch <- prometheus.MustNewConstMetric(c.maxIdleTimeClosed, prometheus.CounterValue, float64(stats.MaxIdleTimeClosed))
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package collectors
import "github.com/prometheus/client_golang/prometheus"
// NewExpvarCollector returns a newly allocated expvar Collector.
//
// An expvar Collector collects metrics from the expvar interface. It provides a
// quick way to expose numeric values that are already exported via expvar as
// Prometheus metrics. Note that the data models of expvar and Prometheus are
// fundamentally different, and that the expvar Collector is inherently slower
// than native Prometheus metrics. Thus, the expvar Collector is probably great
// for experiments and prototyping, but you should seriously consider a more
// direct implementation of Prometheus metrics for monitoring production
// systems.
//
// The exports map has the following meaning:
//
// The keys in the map correspond to expvar keys, i.e. for every expvar key you
// want to export as Prometheus metric, you need an entry in the exports
// map. The descriptor mapped to each key describes how to export the expvar
// value. It defines the name and the help string of the Prometheus metric
// proxying the expvar value. The type will always be Untyped.
//
// For descriptors without variable labels, the expvar value must be a number or
// a bool. The number is then directly exported as the Prometheus sample
// value. (For a bool, 'false' translates to 0 and 'true' to 1). Expvar values
// that are not numbers or bools are silently ignored.
//
// If the descriptor has one variable label, the expvar value must be an expvar
// map. The keys in the expvar map become the various values of the one
// Prometheus label. The values in the expvar map must be numbers or bools again
// as above.
//
// For descriptors with more than one variable label, the expvar must be a
// nested expvar map, i.e. where the values of the topmost map are maps again
// etc. until a depth is reached that corresponds to the number of labels. The
// leaves of that structure must be numbers or bools as above to serve as the
// sample values.
//
// Anything that does not fit into the scheme above is silently ignored.
func NewExpvarCollector(exports map[string]*prometheus.Desc) prometheus.Collector {
//nolint:staticcheck // Ignore SA1019 until v2.
return prometheus.NewExpvarCollector(exports)
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build !go1.17
// +build !go1.17
package collectors
import "github.com/prometheus/client_golang/prometheus"
// NewGoCollector returns a collector that exports metrics about the current Go
// process. This includes memory stats. To collect those, runtime.ReadMemStats
// is called. This requires to “stop the world”, which usually only happens for
// garbage collection (GC). Take the following implications into account when
// deciding whether to use the Go collector:
//
// 1. The performance impact of stopping the world is the more relevant the more
// frequently metrics are collected. However, with Go1.9 or later the
// stop-the-world time per metrics collection is very short (~25µs) so that the
// performance impact will only matter in rare cases. However, with older Go
// versions, the stop-the-world duration depends on the heap size and can be
// quite significant (~1.7 ms/GiB as per
// https://go-review.googlesource.com/c/go/+/34937).
//
// 2. During an ongoing GC, nothing else can stop the world. Therefore, if the
// metrics collection happens to coincide with GC, it will only complete after
// GC has finished. Usually, GC is fast enough to not cause problems. However,
// with a very large heap, GC might take multiple seconds, which is enough to
// cause scrape timeouts in common setups. To avoid this problem, the Go
// collector will use the memstats from a previous collection if
// runtime.ReadMemStats takes more than 1s. However, if there are no previously
// collected memstats, or their collection is more than 5m ago, the collection
// will block until runtime.ReadMemStats succeeds.
//
// NOTE: The problem is solved in Go 1.15, see
// https://github.com/golang/go/issues/19812 for the related Go issue.
func NewGoCollector() prometheus.Collector {
return prometheus.NewGoCollector()
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build go1.17
// +build go1.17
package collectors
import (
"regexp"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/internal"
)
var (
// MetricsAll allows all the metrics to be collected from Go runtime.
MetricsAll = GoRuntimeMetricsRule{regexp.MustCompile("/.*")}
// MetricsGC allows only GC metrics to be collected from Go runtime.
// e.g. go_gc_cycles_automatic_gc_cycles_total
// NOTE: This does not include new class of "/cpu/classes/gc/..." metrics.
// Use custom metric rule to access those.
MetricsGC = GoRuntimeMetricsRule{regexp.MustCompile(`^/gc/.*`)}
// MetricsMemory allows only memory metrics to be collected from Go runtime.
// e.g. go_memory_classes_heap_free_bytes
MetricsMemory = GoRuntimeMetricsRule{regexp.MustCompile(`^/memory/.*`)}
// MetricsScheduler allows only scheduler metrics to be collected from Go runtime.
// e.g. go_sched_goroutines_goroutines
MetricsScheduler = GoRuntimeMetricsRule{regexp.MustCompile(`^/sched/.*`)}
// MetricsDebug allows only debug metrics to be collected from Go runtime.
// e.g. go_godebug_non_default_behavior_gocachetest_events_total
MetricsDebug = GoRuntimeMetricsRule{regexp.MustCompile(`^/godebug/.*`)}
)
// WithGoCollectorMemStatsMetricsDisabled disables metrics that is gathered in runtime.MemStats structure such as:
//
// go_memstats_alloc_bytes
// go_memstats_alloc_bytes_total
// go_memstats_sys_bytes
// go_memstats_mallocs_total
// go_memstats_frees_total
// go_memstats_heap_alloc_bytes
// go_memstats_heap_sys_bytes
// go_memstats_heap_idle_bytes
// go_memstats_heap_inuse_bytes
// go_memstats_heap_released_bytes
// go_memstats_heap_objects
// go_memstats_stack_inuse_bytes
// go_memstats_stack_sys_bytes
// go_memstats_mspan_inuse_bytes
// go_memstats_mspan_sys_bytes
// go_memstats_mcache_inuse_bytes
// go_memstats_mcache_sys_bytes
// go_memstats_buck_hash_sys_bytes
// go_memstats_gc_sys_bytes
// go_memstats_other_sys_bytes
// go_memstats_next_gc_bytes
//
// so the metrics known from pre client_golang v1.12.0,
//
// NOTE(bwplotka): The above represents runtime.MemStats statistics, but they are
// actually implemented using new runtime/metrics package. (except skipped go_memstats_gc_cpu_fraction
// -- see https://github.com/prometheus/client_golang/issues/842#issuecomment-861812034 for explanation).
//
// Some users might want to disable this on collector level (although you can use scrape relabelling on Prometheus),
// because similar metrics can be now obtained using WithGoCollectorRuntimeMetrics. Note that the semantics of new
// metrics might be different, plus the names can be change over time with different Go version.
//
// NOTE(bwplotka): Changing metric names can be tedious at times as the alerts, recording rules and dashboards have to be adjusted.
// The old metrics are also very useful, with many guides and books written about how to interpret them.
//
// As a result our recommendation would be to stick with MemStats like metrics and enable other runtime/metrics if you are interested
// in advanced insights Go provides. See ExampleGoCollector_WithAdvancedGoMetrics.
func WithGoCollectorMemStatsMetricsDisabled() func(options *internal.GoCollectorOptions) {
return func(o *internal.GoCollectorOptions) {
o.DisableMemStatsLikeMetrics = true
}
}
// GoRuntimeMetricsRule allow enabling and configuring particular group of runtime/metrics.
// TODO(bwplotka): Consider adding ability to adjust buckets.
type GoRuntimeMetricsRule struct {
// Matcher represents RE2 expression will match the runtime/metrics from https://golang.bg/src/runtime/metrics/description.go
// Use `regexp.MustCompile` or `regexp.Compile` to create this field.
Matcher *regexp.Regexp
}
// WithGoCollectorRuntimeMetrics allows enabling and configuring particular group of runtime/metrics.
// See the list of metrics https://golang.bg/src/runtime/metrics/description.go (pick the Go version you use there!).
// You can use this option in repeated manner, which will add new rules. The order of rules is important, the last rule
// that matches particular metrics is applied.
func WithGoCollectorRuntimeMetrics(rules ...GoRuntimeMetricsRule) func(options *internal.GoCollectorOptions) {
rs := make([]internal.GoCollectorRule, len(rules))
for i, r := range rules {
rs[i] = internal.GoCollectorRule{
Matcher: r.Matcher,
}
}
return func(o *internal.GoCollectorOptions) {
o.RuntimeMetricRules = append(o.RuntimeMetricRules, rs...)
}
}
// WithoutGoCollectorRuntimeMetrics allows disabling group of runtime/metrics that you might have added in WithGoCollectorRuntimeMetrics.
// It behaves similarly to WithGoCollectorRuntimeMetrics just with deny-list semantics.
func WithoutGoCollectorRuntimeMetrics(matchers ...*regexp.Regexp) func(options *internal.GoCollectorOptions) {
rs := make([]internal.GoCollectorRule, len(matchers))
for i, m := range matchers {
rs[i] = internal.GoCollectorRule{
Matcher: m,
Deny: true,
}
}
return func(o *internal.GoCollectorOptions) {
o.RuntimeMetricRules = append(o.RuntimeMetricRules, rs...)
}
}
// GoCollectionOption represents Go collection option flag.
// Deprecated.
type GoCollectionOption uint32
const (
// GoRuntimeMemStatsCollection represents the metrics represented by runtime.MemStats structure.
//
// Deprecated: Use WithGoCollectorMemStatsMetricsDisabled() function to disable those metrics in the collector.
GoRuntimeMemStatsCollection GoCollectionOption = 1 << iota
// GoRuntimeMetricsCollection is the new set of metrics represented by runtime/metrics package.
//
// Deprecated: Use WithGoCollectorRuntimeMetrics(GoRuntimeMetricsRule{Matcher: regexp.MustCompile("/.*")})
// function to enable those metrics in the collector.
GoRuntimeMetricsCollection
)
// WithGoCollections allows enabling different collections for Go collector on top of base metrics.
//
// Deprecated: Use WithGoCollectorRuntimeMetrics() and WithGoCollectorMemStatsMetricsDisabled() instead to control metrics.
func WithGoCollections(flags GoCollectionOption) func(options *internal.GoCollectorOptions) {
return func(options *internal.GoCollectorOptions) {
if flags&GoRuntimeMemStatsCollection == 0 {
WithGoCollectorMemStatsMetricsDisabled()(options)
}
if flags&GoRuntimeMetricsCollection != 0 {
WithGoCollectorRuntimeMetrics(GoRuntimeMetricsRule{Matcher: regexp.MustCompile("/.*")})(options)
}
}
}
// NewGoCollector returns a collector that exports metrics about the current Go
// process using debug.GCStats (base metrics) and runtime/metrics (both in MemStats style and new ones).
func NewGoCollector(opts ...func(o *internal.GoCollectorOptions)) prometheus.Collector {
//nolint:staticcheck // Ignore SA1019 until v2.
return prometheus.NewGoCollector(opts...)
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package collectors
import "github.com/prometheus/client_golang/prometheus"
// ProcessCollectorOpts defines the behavior of a process metrics collector
// created with NewProcessCollector.
type ProcessCollectorOpts struct {
// PidFn returns the PID of the process the collector collects metrics
// for. It is called upon each collection. By default, the PID of the
// current process is used, as determined on construction time by
// calling os.Getpid().
PidFn func() (int, error)
// If non-empty, each of the collected metrics is prefixed by the
// provided string and an underscore ("_").
Namespace string
// If true, any error encountered during collection is reported as an
// invalid metric (see NewInvalidMetric). Otherwise, errors are ignored
// and the collected metrics will be incomplete. (Possibly, no metrics
// will be collected at all.) While that's usually not desired, it is
// appropriate for the common "mix-in" of process metrics, where process
// metrics are nice to have, but failing to collect them should not
// disrupt the collection of the remaining metrics.
ReportErrors bool
}
// NewProcessCollector returns a collector which exports the current state of
// process metrics including CPU, memory and file descriptor usage as well as
// the process start time. The detailed behavior is defined by the provided
// ProcessCollectorOpts. The zero value of ProcessCollectorOpts creates a
// collector for the current process with an empty namespace string and no error
// reporting.
//
// The collector only works on operating systems with a Linux-style proc
// filesystem and on Microsoft Windows. On other operating systems, it will not
// collect any metrics.
func NewProcessCollector(opts ProcessCollectorOpts) prometheus.Collector {
//nolint:staticcheck // Ignore SA1019 until v2.
return prometheus.NewProcessCollector(prometheus.ProcessCollectorOpts{
PidFn: opts.PidFn,
Namespace: opts.Namespace,
ReportErrors: opts.ReportErrors,
})
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"math"
"sync/atomic"
"time"
dto "github.com/prometheus/client_model/go"
"google.golang.org/protobuf/types/known/timestamppb"
)
// Counter is a Metric that represents a single numerical value that only ever
// goes up. That implies that it cannot be used to count items whose number can
// also go down, e.g. the number of currently running goroutines. Those
// "counters" are represented by Gauges.
//
// A Counter is typically used to count requests served, tasks completed, errors
// occurred, etc.
//
// To create Counter instances, use NewCounter.
type Counter interface {
Metric
Collector
// Inc increments the counter by 1. Use Add to increment it by arbitrary
// non-negative values.
Inc()
// Add adds the given value to the counter. It panics if the value is <
// 0.
Add(float64)
}
// ExemplarAdder is implemented by Counters that offer the option of adding a
// value to the Counter together with an exemplar. Its AddWithExemplar method
// works like the Add method of the Counter interface but also replaces the
// currently saved exemplar (if any) with a new one, created from the provided
// value, the current time as timestamp, and the provided labels. Empty Labels
// will lead to a valid (label-less) exemplar. But if Labels is nil, the current
// exemplar is left in place. AddWithExemplar panics if the value is < 0, if any
// of the provided labels are invalid, or if the provided labels contain more
// than 128 runes in total.
type ExemplarAdder interface {
AddWithExemplar(value float64, exemplar Labels)
}
// CounterOpts is an alias for Opts. See there for doc comments.
type CounterOpts Opts
// CounterVecOpts bundles the options to create a CounterVec metric.
// It is mandatory to set CounterOpts, see there for mandatory fields. VariableLabels
// is optional and can safely be left to its default value.
type CounterVecOpts struct {
CounterOpts
// VariableLabels are used to partition the metric vector by the given set
// of labels. Each label value will be constrained with the optional Constraint
// function, if provided.
VariableLabels ConstrainableLabels
}
// NewCounter creates a new Counter based on the provided CounterOpts.
//
// The returned implementation also implements ExemplarAdder. It is safe to
// perform the corresponding type assertion.
//
// The returned implementation tracks the counter value in two separate
// variables, a float64 and a uint64. The latter is used to track calls of the
// Inc method and calls of the Add method with a value that can be represented
// as a uint64. This allows atomic increments of the counter with optimal
// performance. (It is common to have an Inc call in very hot execution paths.)
// Both internal tracking values are added up in the Write method. This has to
// be taken into account when it comes to precision and overflow behavior.
func NewCounter(opts CounterOpts) Counter {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
)
if opts.now == nil {
opts.now = time.Now
}
result := &counter{desc: desc, labelPairs: desc.constLabelPairs, now: opts.now}
result.init(result) // Init self-collection.
result.createdTs = timestamppb.New(opts.now())
return result
}
type counter struct {
// valBits contains the bits of the represented float64 value, while
// valInt stores values that are exact integers. Both have to go first
// in the struct to guarantee alignment for atomic operations.
// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
valBits uint64
valInt uint64
selfCollector
desc *Desc
createdTs *timestamppb.Timestamp
labelPairs []*dto.LabelPair
exemplar atomic.Value // Containing nil or a *dto.Exemplar.
// now is for testing purposes, by default it's time.Now.
now func() time.Time
}
func (c *counter) Desc() *Desc {
return c.desc
}
func (c *counter) Add(v float64) {
if v < 0 {
panic(errors.New("counter cannot decrease in value"))
}
ival := uint64(v)
if float64(ival) == v {
atomic.AddUint64(&c.valInt, ival)
return
}
atomicUpdateFloat(&c.valBits, func(oldVal float64) float64 {
return oldVal + v
})
}
func (c *counter) AddWithExemplar(v float64, e Labels) {
c.Add(v)
c.updateExemplar(v, e)
}
func (c *counter) Inc() {
atomic.AddUint64(&c.valInt, 1)
}
func (c *counter) get() float64 {
fval := math.Float64frombits(atomic.LoadUint64(&c.valBits))
ival := atomic.LoadUint64(&c.valInt)
return fval + float64(ival)
}
func (c *counter) Write(out *dto.Metric) error {
// Read the Exemplar first and the value second. This is to avoid a race condition
// where users see an exemplar for a not-yet-existing observation.
var exemplar *dto.Exemplar
if e := c.exemplar.Load(); e != nil {
exemplar = e.(*dto.Exemplar)
}
val := c.get()
return populateMetric(CounterValue, val, c.labelPairs, exemplar, out, c.createdTs)
}
func (c *counter) updateExemplar(v float64, l Labels) {
if l == nil {
return
}
e, err := newExemplar(v, c.now(), l)
if err != nil {
panic(err)
}
c.exemplar.Store(e)
}
// CounterVec is a Collector that bundles a set of Counters that all share the
// same Desc, but have different values for their variable labels. This is used
// if you want to count the same thing partitioned by various dimensions
// (e.g. number of HTTP requests, partitioned by response code and
// method). Create instances with NewCounterVec.
type CounterVec struct {
*MetricVec
}
// NewCounterVec creates a new CounterVec based on the provided CounterOpts and
// partitioned by the given label names.
func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
return V2.NewCounterVec(CounterVecOpts{
CounterOpts: opts,
VariableLabels: UnconstrainedLabels(labelNames),
})
}
// NewCounterVec creates a new CounterVec based on the provided CounterVecOpts.
func (v2) NewCounterVec(opts CounterVecOpts) *CounterVec {
desc := V2.NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
opts.VariableLabels,
opts.ConstLabels,
)
if opts.now == nil {
opts.now = time.Now
}
return &CounterVec{
MetricVec: NewMetricVec(desc, func(lvs ...string) Metric {
if len(lvs) != len(desc.variableLabels.names) {
panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.names, lvs))
}
result := &counter{desc: desc, labelPairs: MakeLabelPairs(desc, lvs), now: opts.now}
result.init(result) // Init self-collection.
result.createdTs = timestamppb.New(opts.now())
return result
}),
}
}
// GetMetricWithLabelValues returns the Counter for the given slice of label
// values (same order as the variable labels in Desc). If that combination of
// label values is accessed for the first time, a new Counter is created.
//
// It is possible to call this method without using the returned Counter to only
// create the new Counter but leave it at its starting value 0. See also the
// SummaryVec example.
//
// Keeping the Counter for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Counter from the CounterVec. In that case,
// the Counter will still exist, but it will not be exported anymore, even if a
// Counter with the same label values is created later.
//
// An error is returned if the number of label values is not the same as the
// number of variable labels in Desc (minus any curried labels).
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the GaugeVec example.
func (v *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
metric, err := v.MetricVec.GetMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Counter), err
}
return nil, err
}
// GetMetricWith returns the Counter for the given Labels map (the label names
// must match those of the variable labels in Desc). If that label map is
// accessed for the first time, a new Counter is created. Implications of
// creating a Counter without using it and keeping the Counter for later use are
// the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the variable labels in Desc (minus any curried labels).
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
metric, err := v.MetricVec.GetMetricWith(labels)
if metric != nil {
return metric.(Counter), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. Not returning an
// error allows shortcuts like
//
// myVec.WithLabelValues("404", "GET").Add(42)
func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
c, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return c
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. Not returning an error allows shortcuts like
//
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
func (v *CounterVec) With(labels Labels) Counter {
c, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return c
}
// CurryWith returns a vector curried with the provided labels, i.e. the
// returned vector has those labels pre-set for all labeled operations performed
// on it. The cardinality of the curried vector is reduced accordingly. The
// order of the remaining labels stays the same (just with the curried labels
// taken out of the sequence which is relevant for the
// (GetMetric)WithLabelValues methods). It is possible to curry a curried
// vector, but only with labels not yet used for currying before.
//
// The metrics contained in the CounterVec are shared between the curried and
// uncurried vectors. They are just accessed differently. Curried and uncurried
// vectors behave identically in terms of collection. Only one must be
// registered with a given registry (usually the uncurried version). The Reset
// method deletes all metrics, even if called on a curried vector.
func (v *CounterVec) CurryWith(labels Labels) (*CounterVec, error) {
vec, err := v.MetricVec.CurryWith(labels)
if vec != nil {
return &CounterVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *CounterVec) MustCurryWith(labels Labels) *CounterVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
// CounterFunc is a Counter whose value is determined at collect time by calling a
// provided function.
//
// To create CounterFunc instances, use NewCounterFunc.
type CounterFunc interface {
Metric
Collector
}
// NewCounterFunc creates a new CounterFunc based on the provided
// CounterOpts. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where a CounterFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe. The function should also honor
// the contract for a Counter (values only go up, not down), but compliance will
// not be checked.
//
// Check out the ExampleGaugeFunc examples for the similar GaugeFunc.
func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), CounterValue, function)
}

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@ -0,0 +1,210 @@
// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"sort"
"strings"
"github.com/cespare/xxhash/v2"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/common/model"
"google.golang.org/protobuf/proto"
"github.com/prometheus/client_golang/prometheus/internal"
)
// Desc is the descriptor used by every Prometheus Metric. It is essentially
// the immutable meta-data of a Metric. The normal Metric implementations
// included in this package manage their Desc under the hood. Users only have to
// deal with Desc if they use advanced features like the ExpvarCollector or
// custom Collectors and Metrics.
//
// Descriptors registered with the same registry have to fulfill certain
// consistency and uniqueness criteria if they share the same fully-qualified
// name: They must have the same help string and the same label names (aka label
// dimensions) in each, constLabels and variableLabels, but they must differ in
// the values of the constLabels.
//
// Descriptors that share the same fully-qualified names and the same label
// values of their constLabels are considered equal.
//
// Use NewDesc to create new Desc instances.
type Desc struct {
// fqName has been built from Namespace, Subsystem, and Name.
fqName string
// help provides some helpful information about this metric.
help string
// constLabelPairs contains precalculated DTO label pairs based on
// the constant labels.
constLabelPairs []*dto.LabelPair
// variableLabels contains names of labels and normalization function for
// which the metric maintains variable values.
variableLabels *compiledLabels
// id is a hash of the values of the ConstLabels and fqName. This
// must be unique among all registered descriptors and can therefore be
// used as an identifier of the descriptor.
id uint64
// dimHash is a hash of the label names (preset and variable) and the
// Help string. Each Desc with the same fqName must have the same
// dimHash.
dimHash uint64
// err is an error that occurred during construction. It is reported on
// registration time.
err error
}
// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
// and will be reported on registration time. variableLabels and constLabels can
// be nil if no such labels should be set. fqName must not be empty.
//
// variableLabels only contain the label names. Their label values are variable
// and therefore not part of the Desc. (They are managed within the Metric.)
//
// For constLabels, the label values are constant. Therefore, they are fully
// specified in the Desc. See the Collector example for a usage pattern.
func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
return V2.NewDesc(fqName, help, UnconstrainedLabels(variableLabels), constLabels)
}
// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
// and will be reported on registration time. variableLabels and constLabels can
// be nil if no such labels should be set. fqName must not be empty.
//
// variableLabels only contain the label names and normalization functions. Their
// label values are variable and therefore not part of the Desc. (They are managed
// within the Metric.)
//
// For constLabels, the label values are constant. Therefore, they are fully
// specified in the Desc. See the Collector example for a usage pattern.
func (v2) NewDesc(fqName, help string, variableLabels ConstrainableLabels, constLabels Labels) *Desc {
d := &Desc{
fqName: fqName,
help: help,
variableLabels: variableLabels.compile(),
}
if !model.IsValidMetricName(model.LabelValue(fqName)) {
d.err = fmt.Errorf("%q is not a valid metric name", fqName)
return d
}
// labelValues contains the label values of const labels (in order of
// their sorted label names) plus the fqName (at position 0).
labelValues := make([]string, 1, len(constLabels)+1)
labelValues[0] = fqName
labelNames := make([]string, 0, len(constLabels)+len(d.variableLabels.names))
labelNameSet := map[string]struct{}{}
// First add only the const label names and sort them...
for labelName := range constLabels {
if !checkLabelName(labelName) {
d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
return d
}
labelNames = append(labelNames, labelName)
labelNameSet[labelName] = struct{}{}
}
sort.Strings(labelNames)
// ... so that we can now add const label values in the order of their names.
for _, labelName := range labelNames {
labelValues = append(labelValues, constLabels[labelName])
}
// Validate the const label values. They can't have a wrong cardinality, so
// use in len(labelValues) as expectedNumberOfValues.
if err := validateLabelValues(labelValues, len(labelValues)); err != nil {
d.err = err
return d
}
// Now add the variable label names, but prefix them with something that
// cannot be in a regular label name. That prevents matching the label
// dimension with a different mix between preset and variable labels.
for _, label := range d.variableLabels.names {
if !checkLabelName(label) {
d.err = fmt.Errorf("%q is not a valid label name for metric %q", label, fqName)
return d
}
labelNames = append(labelNames, "$"+label)
labelNameSet[label] = struct{}{}
}
if len(labelNames) != len(labelNameSet) {
d.err = fmt.Errorf("duplicate label names in constant and variable labels for metric %q", fqName)
return d
}
xxh := xxhash.New()
for _, val := range labelValues {
xxh.WriteString(val)
xxh.Write(separatorByteSlice)
}
d.id = xxh.Sum64()
// Sort labelNames so that order doesn't matter for the hash.
sort.Strings(labelNames)
// Now hash together (in this order) the help string and the sorted
// label names.
xxh.Reset()
xxh.WriteString(help)
xxh.Write(separatorByteSlice)
for _, labelName := range labelNames {
xxh.WriteString(labelName)
xxh.Write(separatorByteSlice)
}
d.dimHash = xxh.Sum64()
d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
for n, v := range constLabels {
d.constLabelPairs = append(d.constLabelPairs, &dto.LabelPair{
Name: proto.String(n),
Value: proto.String(v),
})
}
sort.Sort(internal.LabelPairSorter(d.constLabelPairs))
return d
}
// NewInvalidDesc returns an invalid descriptor, i.e. a descriptor with the
// provided error set. If a collector returning such a descriptor is registered,
// registration will fail with the provided error. NewInvalidDesc can be used by
// a Collector to signal inability to describe itself.
func NewInvalidDesc(err error) *Desc {
return &Desc{
err: err,
}
}
func (d *Desc) String() string {
lpStrings := make([]string, 0, len(d.constLabelPairs))
for _, lp := range d.constLabelPairs {
lpStrings = append(
lpStrings,
fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()),
)
}
vlStrings := []string{}
if d.variableLabels != nil {
vlStrings = make([]string, 0, len(d.variableLabels.names))
for _, vl := range d.variableLabels.names {
if fn, ok := d.variableLabels.labelConstraints[vl]; ok && fn != nil {
vlStrings = append(vlStrings, fmt.Sprintf("c(%s)", vl))
} else {
vlStrings = append(vlStrings, vl)
}
}
}
return fmt.Sprintf(
"Desc{fqName: %q, help: %q, constLabels: {%s}, variableLabels: {%s}}",
d.fqName,
d.help,
strings.Join(lpStrings, ","),
strings.Join(vlStrings, ","),
)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package prometheus is the core instrumentation package. It provides metrics
// primitives to instrument code for monitoring. It also offers a registry for
// metrics. Sub-packages allow to expose the registered metrics via HTTP
// (package promhttp) or push them to a Pushgateway (package push). There is
// also a sub-package promauto, which provides metrics constructors with
// automatic registration.
//
// All exported functions and methods are safe to be used concurrently unless
// specified otherwise.
//
// # A Basic Example
//
// As a starting point, a very basic usage example:
//
// package main
//
// import (
// "log"
// "net/http"
//
// "github.com/prometheus/client_golang/prometheus"
// "github.com/prometheus/client_golang/prometheus/promhttp"
// )
//
// type metrics struct {
// cpuTemp prometheus.Gauge
// hdFailures *prometheus.CounterVec
// }
//
// func NewMetrics(reg prometheus.Registerer) *metrics {
// m := &metrics{
// cpuTemp: prometheus.NewGauge(prometheus.GaugeOpts{
// Name: "cpu_temperature_celsius",
// Help: "Current temperature of the CPU.",
// }),
// hdFailures: prometheus.NewCounterVec(
// prometheus.CounterOpts{
// Name: "hd_errors_total",
// Help: "Number of hard-disk errors.",
// },
// []string{"device"},
// ),
// }
// reg.MustRegister(m.cpuTemp)
// reg.MustRegister(m.hdFailures)
// return m
// }
//
// func main() {
// // Create a non-global registry.
// reg := prometheus.NewRegistry()
//
// // Create new metrics and register them using the custom registry.
// m := NewMetrics(reg)
// // Set values for the new created metrics.
// m.cpuTemp.Set(65.3)
// m.hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc()
//
// // Expose metrics and custom registry via an HTTP server
// // using the HandleFor function. "/metrics" is the usual endpoint for that.
// http.Handle("/metrics", promhttp.HandlerFor(reg, promhttp.HandlerOpts{Registry: reg}))
// log.Fatal(http.ListenAndServe(":8080", nil))
// }
//
// This is a complete program that exports two metrics, a Gauge and a Counter,
// the latter with a label attached to turn it into a (one-dimensional) vector.
// It register the metrics using a custom registry and exposes them via an HTTP server
// on the /metrics endpoint.
//
// # Metrics
//
// The number of exported identifiers in this package might appear a bit
// overwhelming. However, in addition to the basic plumbing shown in the example
// above, you only need to understand the different metric types and their
// vector versions for basic usage. Furthermore, if you are not concerned with
// fine-grained control of when and how to register metrics with the registry,
// have a look at the promauto package, which will effectively allow you to
// ignore registration altogether in simple cases.
//
// Above, you have already touched the Counter and the Gauge. There are two more
// advanced metric types: the Summary and Histogram. A more thorough description
// of those four metric types can be found in the Prometheus docs:
// https://prometheus.io/docs/concepts/metric_types/
//
// In addition to the fundamental metric types Gauge, Counter, Summary, and
// Histogram, a very important part of the Prometheus data model is the
// partitioning of samples along dimensions called labels, which results in
// metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec,
// and HistogramVec.
//
// While only the fundamental metric types implement the Metric interface, both
// the metrics and their vector versions implement the Collector interface. A
// Collector manages the collection of a number of Metrics, but for convenience,
// a Metric can also “collect itself”. Note that Gauge, Counter, Summary, and
// Histogram are interfaces themselves while GaugeVec, CounterVec, SummaryVec,
// and HistogramVec are not.
//
// To create instances of Metrics and their vector versions, you need a suitable
// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, or HistogramOpts.
//
// # Custom Collectors and constant Metrics
//
// While you could create your own implementations of Metric, most likely you
// will only ever implement the Collector interface on your own. At a first
// glance, a custom Collector seems handy to bundle Metrics for common
// registration (with the prime example of the different metric vectors above,
// which bundle all the metrics of the same name but with different labels).
//
// There is a more involved use case, too: If you already have metrics
// available, created outside of the Prometheus context, you don't need the
// interface of the various Metric types. You essentially want to mirror the
// existing numbers into Prometheus Metrics during collection. An own
// implementation of the Collector interface is perfect for that. You can create
// Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
// NewConstSummary (and their respective Must… versions). NewConstMetric is used
// for all metric types with just a float64 as their value: Counter, Gauge, and
// a special “type” called Untyped. Use the latter if you are not sure if the
// mirrored metric is a Counter or a Gauge. Creation of the Metric instance
// happens in the Collect method. The Describe method has to return separate
// Desc instances, representative of the “throw-away” metrics to be created
// later. NewDesc comes in handy to create those Desc instances. Alternatively,
// you could return no Desc at all, which will mark the Collector “unchecked”.
// No checks are performed at registration time, but metric consistency will
// still be ensured at scrape time, i.e. any inconsistencies will lead to scrape
// errors. Thus, with unchecked Collectors, the responsibility to not collect
// metrics that lead to inconsistencies in the total scrape result lies with the
// implementer of the Collector. While this is not a desirable state, it is
// sometimes necessary. The typical use case is a situation where the exact
// metrics to be returned by a Collector cannot be predicted at registration
// time, but the implementer has sufficient knowledge of the whole system to
// guarantee metric consistency.
//
// The Collector example illustrates the use case. You can also look at the
// source code of the processCollector (mirroring process metrics), the
// goCollector (mirroring Go metrics), or the expvarCollector (mirroring expvar
// metrics) as examples that are used in this package itself.
//
// If you just need to call a function to get a single float value to collect as
// a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting
// shortcuts.
//
// # Advanced Uses of the Registry
//
// While MustRegister is the by far most common way of registering a Collector,
// sometimes you might want to handle the errors the registration might cause.
// As suggested by the name, MustRegister panics if an error occurs. With the
// Register function, the error is returned and can be handled.
//
// An error is returned if the registered Collector is incompatible or
// inconsistent with already registered metrics. The registry aims for
// consistency of the collected metrics according to the Prometheus data model.
// Inconsistencies are ideally detected at registration time, not at collect
// time. The former will usually be detected at start-up time of a program,
// while the latter will only happen at scrape time, possibly not even on the
// first scrape if the inconsistency only becomes relevant later. That is the
// main reason why a Collector and a Metric have to describe themselves to the
// registry.
//
// So far, everything we did operated on the so-called default registry, as it
// can be found in the global DefaultRegisterer variable. With NewRegistry, you
// can create a custom registry, or you can even implement the Registerer or
// Gatherer interfaces yourself. The methods Register and Unregister work in the
// same way on a custom registry as the global functions Register and Unregister
// on the default registry.
//
// There are a number of uses for custom registries: You can use registries with
// special properties, see NewPedanticRegistry. You can avoid global state, as
// it is imposed by the DefaultRegisterer. You can use multiple registries at
// the same time to expose different metrics in different ways. You can use
// separate registries for testing purposes.
//
// Also note that the DefaultRegisterer comes registered with a Collector for Go
// runtime metrics (via NewGoCollector) and a Collector for process metrics (via
// NewProcessCollector). With a custom registry, you are in control and decide
// yourself about the Collectors to register.
//
// # HTTP Exposition
//
// The Registry implements the Gatherer interface. The caller of the Gather
// method can then expose the gathered metrics in some way. Usually, the metrics
// are served via HTTP on the /metrics endpoint. That's happening in the example
// above. The tools to expose metrics via HTTP are in the promhttp sub-package.
//
// # Pushing to the Pushgateway
//
// Function for pushing to the Pushgateway can be found in the push sub-package.
//
// # Graphite Bridge
//
// Functions and examples to push metrics from a Gatherer to Graphite can be
// found in the graphite sub-package.
//
// # Other Means of Exposition
//
// More ways of exposing metrics can easily be added by following the approaches
// of the existing implementations.
package prometheus

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"encoding/json"
"expvar"
)
type expvarCollector struct {
exports map[string]*Desc
}
// NewExpvarCollector is the obsolete version of collectors.NewExpvarCollector.
// See there for documentation.
//
// Deprecated: Use collectors.NewExpvarCollector instead.
func NewExpvarCollector(exports map[string]*Desc) Collector {
return &expvarCollector{
exports: exports,
}
}
// Describe implements Collector.
func (e *expvarCollector) Describe(ch chan<- *Desc) {
for _, desc := range e.exports {
ch <- desc
}
}
// Collect implements Collector.
func (e *expvarCollector) Collect(ch chan<- Metric) {
for name, desc := range e.exports {
var m Metric
expVar := expvar.Get(name)
if expVar == nil {
continue
}
var v interface{}
labels := make([]string, len(desc.variableLabels.names))
if err := json.Unmarshal([]byte(expVar.String()), &v); err != nil {
ch <- NewInvalidMetric(desc, err)
continue
}
var processValue func(v interface{}, i int)
processValue = func(v interface{}, i int) {
if i >= len(labels) {
copiedLabels := append(make([]string, 0, len(labels)), labels...)
switch v := v.(type) {
case float64:
m = MustNewConstMetric(desc, UntypedValue, v, copiedLabels...)
case bool:
if v {
m = MustNewConstMetric(desc, UntypedValue, 1, copiedLabels...)
} else {
m = MustNewConstMetric(desc, UntypedValue, 0, copiedLabels...)
}
default:
return
}
ch <- m
return
}
vm, ok := v.(map[string]interface{})
if !ok {
return
}
for lv, val := range vm {
labels[i] = lv
processValue(val, i+1)
}
}
processValue(v, 0)
}
}

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// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// Inline and byte-free variant of hash/fnv's fnv64a.
const (
offset64 = 14695981039346656037
prime64 = 1099511628211
)
// hashNew initializies a new fnv64a hash value.
func hashNew() uint64 {
return offset64
}
// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
func hashAdd(h uint64, s string) uint64 {
for i := 0; i < len(s); i++ {
h ^= uint64(s[i])
h *= prime64
}
return h
}
// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
func hashAddByte(h uint64, b byte) uint64 {
h ^= uint64(b)
h *= prime64
return h
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"math"
"sync/atomic"
"time"
dto "github.com/prometheus/client_model/go"
)
// Gauge is a Metric that represents a single numerical value that can
// arbitrarily go up and down.
//
// A Gauge is typically used for measured values like temperatures or current
// memory usage, but also "counts" that can go up and down, like the number of
// running goroutines.
//
// To create Gauge instances, use NewGauge.
type Gauge interface {
Metric
Collector
// Set sets the Gauge to an arbitrary value.
Set(float64)
// Inc increments the Gauge by 1. Use Add to increment it by arbitrary
// values.
Inc()
// Dec decrements the Gauge by 1. Use Sub to decrement it by arbitrary
// values.
Dec()
// Add adds the given value to the Gauge. (The value can be negative,
// resulting in a decrease of the Gauge.)
Add(float64)
// Sub subtracts the given value from the Gauge. (The value can be
// negative, resulting in an increase of the Gauge.)
Sub(float64)
// SetToCurrentTime sets the Gauge to the current Unix time in seconds.
SetToCurrentTime()
}
// GaugeOpts is an alias for Opts. See there for doc comments.
type GaugeOpts Opts
// GaugeVecOpts bundles the options to create a GaugeVec metric.
// It is mandatory to set GaugeOpts, see there for mandatory fields. VariableLabels
// is optional and can safely be left to its default value.
type GaugeVecOpts struct {
GaugeOpts
// VariableLabels are used to partition the metric vector by the given set
// of labels. Each label value will be constrained with the optional Constraint
// function, if provided.
VariableLabels ConstrainableLabels
}
// NewGauge creates a new Gauge based on the provided GaugeOpts.
//
// The returned implementation is optimized for a fast Set method. If you have a
// choice for managing the value of a Gauge via Set vs. Inc/Dec/Add/Sub, pick
// the former. For example, the Inc method of the returned Gauge is slower than
// the Inc method of a Counter returned by NewCounter. This matches the typical
// scenarios for Gauges and Counters, where the former tends to be Set-heavy and
// the latter Inc-heavy.
func NewGauge(opts GaugeOpts) Gauge {
desc := NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
)
result := &gauge{desc: desc, labelPairs: desc.constLabelPairs}
result.init(result) // Init self-collection.
return result
}
type gauge struct {
// valBits contains the bits of the represented float64 value. It has
// to go first in the struct to guarantee alignment for atomic
// operations. http://golang.org/pkg/sync/atomic/#pkg-note-BUG
valBits uint64
selfCollector
desc *Desc
labelPairs []*dto.LabelPair
}
func (g *gauge) Desc() *Desc {
return g.desc
}
func (g *gauge) Set(val float64) {
atomic.StoreUint64(&g.valBits, math.Float64bits(val))
}
func (g *gauge) SetToCurrentTime() {
g.Set(float64(time.Now().UnixNano()) / 1e9)
}
func (g *gauge) Inc() {
g.Add(1)
}
func (g *gauge) Dec() {
g.Add(-1)
}
func (g *gauge) Add(val float64) {
atomicUpdateFloat(&g.valBits, func(oldVal float64) float64 {
return oldVal + val
})
}
func (g *gauge) Sub(val float64) {
g.Add(val * -1)
}
func (g *gauge) Write(out *dto.Metric) error {
val := math.Float64frombits(atomic.LoadUint64(&g.valBits))
return populateMetric(GaugeValue, val, g.labelPairs, nil, out, nil)
}
// GaugeVec is a Collector that bundles a set of Gauges that all share the same
// Desc, but have different values for their variable labels. This is used if
// you want to count the same thing partitioned by various dimensions
// (e.g. number of operations queued, partitioned by user and operation
// type). Create instances with NewGaugeVec.
type GaugeVec struct {
*MetricVec
}
// NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
// partitioned by the given label names.
func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
return V2.NewGaugeVec(GaugeVecOpts{
GaugeOpts: opts,
VariableLabels: UnconstrainedLabels(labelNames),
})
}
// NewGaugeVec creates a new GaugeVec based on the provided GaugeVecOpts.
func (v2) NewGaugeVec(opts GaugeVecOpts) *GaugeVec {
desc := V2.NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
opts.VariableLabels,
opts.ConstLabels,
)
return &GaugeVec{
MetricVec: NewMetricVec(desc, func(lvs ...string) Metric {
if len(lvs) != len(desc.variableLabels.names) {
panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.names, lvs))
}
result := &gauge{desc: desc, labelPairs: MakeLabelPairs(desc, lvs)}
result.init(result) // Init self-collection.
return result
}),
}
}
// GetMetricWithLabelValues returns the Gauge for the given slice of label
// values (same order as the variable labels in Desc). If that combination of
// label values is accessed for the first time, a new Gauge is created.
//
// It is possible to call this method without using the returned Gauge to only
// create the new Gauge but leave it at its starting value 0. See also the
// SummaryVec example.
//
// Keeping the Gauge for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Gauge from the GaugeVec. In that case, the
// Gauge will still exist, but it will not be exported anymore, even if a
// Gauge with the same label values is created later. See also the CounterVec
// example.
//
// An error is returned if the number of label values is not the same as the
// number of variable labels in Desc (minus any curried labels).
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
func (v *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
metric, err := v.MetricVec.GetMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Gauge), err
}
return nil, err
}
// GetMetricWith returns the Gauge for the given Labels map (the label names
// must match those of the variable labels in Desc). If that label map is
// accessed for the first time, a new Gauge is created. Implications of
// creating a Gauge without using it and keeping the Gauge for later use are
// the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the variable labels in Desc (minus any curried labels).
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
metric, err := v.MetricVec.GetMetricWith(labels)
if metric != nil {
return metric.(Gauge), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. Not returning an
// error allows shortcuts like
//
// myVec.WithLabelValues("404", "GET").Add(42)
func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
g, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return g
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. Not returning an error allows shortcuts like
//
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
func (v *GaugeVec) With(labels Labels) Gauge {
g, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return g
}
// CurryWith returns a vector curried with the provided labels, i.e. the
// returned vector has those labels pre-set for all labeled operations performed
// on it. The cardinality of the curried vector is reduced accordingly. The
// order of the remaining labels stays the same (just with the curried labels
// taken out of the sequence which is relevant for the
// (GetMetric)WithLabelValues methods). It is possible to curry a curried
// vector, but only with labels not yet used for currying before.
//
// The metrics contained in the GaugeVec are shared between the curried and
// uncurried vectors. They are just accessed differently. Curried and uncurried
// vectors behave identically in terms of collection. Only one must be
// registered with a given registry (usually the uncurried version). The Reset
// method deletes all metrics, even if called on a curried vector.
func (v *GaugeVec) CurryWith(labels Labels) (*GaugeVec, error) {
vec, err := v.MetricVec.CurryWith(labels)
if vec != nil {
return &GaugeVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *GaugeVec) MustCurryWith(labels Labels) *GaugeVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
// GaugeFunc is a Gauge whose value is determined at collect time by calling a
// provided function.
//
// To create GaugeFunc instances, use NewGaugeFunc.
type GaugeFunc interface {
Metric
Collector
}
// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
// value reported is determined by calling the given function from within the
// Write method. Take into account that metric collection may happen
// concurrently. Therefore, it must be safe to call the provided function
// concurrently.
//
// NewGaugeFunc is a good way to create an “info” style metric with a constant
// value of 1. Example:
// https://github.com/prometheus/common/blob/8558a5b7db3c84fa38b4766966059a7bd5bfa2ee/version/info.go#L36-L56
func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), GaugeValue, function)
}

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build !js || wasm
// +build !js wasm
package prometheus
import "os"
func getPIDFn() func() (int, error) {
pid := os.Getpid()
return func() (int, error) {
return pid, nil
}
}

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build js && !wasm
// +build js,!wasm
package prometheus
func getPIDFn() func() (int, error) {
return func() (int, error) {
return 1, nil
}
}

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// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"runtime"
"runtime/debug"
"time"
)
// goRuntimeMemStats provides the metrics initially provided by runtime.ReadMemStats.
// From Go 1.17 those similar (and better) statistics are provided by runtime/metrics, so
// while eval closure works on runtime.MemStats, the struct from Go 1.17+ is
// populated using runtime/metrics. Those are the defaults we can't alter.
func goRuntimeMemStats() memStatsMetrics {
return memStatsMetrics{
{
desc: NewDesc(
memstatNamespace("alloc_bytes"),
"Number of bytes allocated in heap and currently in use. Equals to /memory/classes/heap/objects:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("alloc_bytes_total"),
"Total number of bytes allocated in heap until now, even if released already. Equals to /gc/heap/allocs:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("sys_bytes"),
"Number of bytes obtained from system. Equals to /memory/classes/total:byte.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mallocs_total"),
// TODO(bwplotka): We could add go_memstats_heap_objects, probably useful for discovery. Let's gather more feedback, kind of a waste of bytes for everybody for compatibility reasons to keep both, and we can't really rename/remove useful metric.
"Total number of heap objects allocated, both live and gc-ed. Semantically a counter version for go_memstats_heap_objects gauge. Equals to /gc/heap/allocs:objects + /gc/heap/tiny/allocs:objects.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("frees_total"),
"Total number of heap objects frees. Equals to /gc/heap/frees:objects + /gc/heap/tiny/allocs:objects.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
valType: CounterValue,
}, {
desc: NewDesc(
memstatNamespace("heap_alloc_bytes"),
"Number of heap bytes allocated and currently in use, same as go_memstats_alloc_bytes. Equals to /memory/classes/heap/objects:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_sys_bytes"),
"Number of heap bytes obtained from system. Equals to /memory/classes/heap/objects:bytes + /memory/classes/heap/unused:bytes + /memory/classes/heap/released:bytes + /memory/classes/heap/free:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_idle_bytes"),
"Number of heap bytes waiting to be used. Equals to /memory/classes/heap/released:bytes + /memory/classes/heap/free:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_inuse_bytes"),
"Number of heap bytes that are in use. Equals to /memory/classes/heap/objects:bytes + /memory/classes/heap/unused:bytes",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_released_bytes"),
"Number of heap bytes released to OS. Equals to /memory/classes/heap/released:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("heap_objects"),
"Number of currently allocated objects. Equals to /gc/heap/objects:objects.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("stack_inuse_bytes"),
"Number of bytes obtained from system for stack allocator in non-CGO environments. Equals to /memory/classes/heap/stacks:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("stack_sys_bytes"),
"Number of bytes obtained from system for stack allocator. Equals to /memory/classes/heap/stacks:bytes + /memory/classes/os-stacks:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mspan_inuse_bytes"),
"Number of bytes in use by mspan structures. Equals to /memory/classes/metadata/mspan/inuse:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mspan_sys_bytes"),
"Number of bytes used for mspan structures obtained from system. Equals to /memory/classes/metadata/mspan/inuse:bytes + /memory/classes/metadata/mspan/free:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mcache_inuse_bytes"),
"Number of bytes in use by mcache structures. Equals to /memory/classes/metadata/mcache/inuse:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("mcache_sys_bytes"),
"Number of bytes used for mcache structures obtained from system. Equals to /memory/classes/metadata/mcache/inuse:bytes + /memory/classes/metadata/mcache/free:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("buck_hash_sys_bytes"),
"Number of bytes used by the profiling bucket hash table. Equals to /memory/classes/profiling/buckets:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("gc_sys_bytes"),
"Number of bytes used for garbage collection system metadata. Equals to /memory/classes/metadata/other:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("other_sys_bytes"),
"Number of bytes used for other system allocations. Equals to /memory/classes/other:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
valType: GaugeValue,
}, {
desc: NewDesc(
memstatNamespace("next_gc_bytes"),
"Number of heap bytes when next garbage collection will take place. Equals to /gc/heap/goal:bytes.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
valType: GaugeValue,
},
}
}
type baseGoCollector struct {
goroutinesDesc *Desc
threadsDesc *Desc
gcDesc *Desc
gcLastTimeDesc *Desc
goInfoDesc *Desc
}
func newBaseGoCollector() baseGoCollector {
return baseGoCollector{
goroutinesDesc: NewDesc(
"go_goroutines",
"Number of goroutines that currently exist.",
nil, nil),
threadsDesc: NewDesc(
"go_threads",
"Number of OS threads created.",
nil, nil),
gcDesc: NewDesc(
"go_gc_duration_seconds",
"A summary of the wall-time pause (stop-the-world) duration in garbage collection cycles.",
nil, nil),
gcLastTimeDesc: NewDesc(
"go_memstats_last_gc_time_seconds",
"Number of seconds since 1970 of last garbage collection.",
nil, nil),
goInfoDesc: NewDesc(
"go_info",
"Information about the Go environment.",
nil, Labels{"version": runtime.Version()}),
}
}
// Describe returns all descriptions of the collector.
func (c *baseGoCollector) Describe(ch chan<- *Desc) {
ch <- c.goroutinesDesc
ch <- c.threadsDesc
ch <- c.gcDesc
ch <- c.gcLastTimeDesc
ch <- c.goInfoDesc
}
// Collect returns the current state of all metrics of the collector.
func (c *baseGoCollector) Collect(ch chan<- Metric) {
ch <- MustNewConstMetric(c.goroutinesDesc, GaugeValue, float64(runtime.NumGoroutine()))
n := getRuntimeNumThreads()
ch <- MustNewConstMetric(c.threadsDesc, GaugeValue, n)
var stats debug.GCStats
stats.PauseQuantiles = make([]time.Duration, 5)
debug.ReadGCStats(&stats)
quantiles := make(map[float64]float64)
for idx, pq := range stats.PauseQuantiles[1:] {
quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds()
}
quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), stats.PauseTotal.Seconds(), quantiles)
ch <- MustNewConstMetric(c.gcLastTimeDesc, GaugeValue, float64(stats.LastGC.UnixNano())/1e9)
ch <- MustNewConstMetric(c.goInfoDesc, GaugeValue, 1)
}
func memstatNamespace(s string) string {
return "go_memstats_" + s
}
// memStatsMetrics provide description, evaluator, runtime/metrics name, and
// value type for memstat metrics.
type memStatsMetrics []struct {
desc *Desc
eval func(*runtime.MemStats) float64
valType ValueType
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build !go1.17
// +build !go1.17
package prometheus
import (
"runtime"
"sync"
"time"
)
type goCollector struct {
base baseGoCollector
// ms... are memstats related.
msLast *runtime.MemStats // Previously collected memstats.
msLastTimestamp time.Time
msMtx sync.Mutex // Protects msLast and msLastTimestamp.
msMetrics memStatsMetrics
msRead func(*runtime.MemStats) // For mocking in tests.
msMaxWait time.Duration // Wait time for fresh memstats.
msMaxAge time.Duration // Maximum allowed age of old memstats.
}
// NewGoCollector is the obsolete version of collectors.NewGoCollector.
// See there for documentation.
//
// Deprecated: Use collectors.NewGoCollector instead.
func NewGoCollector() Collector {
msMetrics := goRuntimeMemStats()
msMetrics = append(msMetrics, struct {
desc *Desc
eval func(*runtime.MemStats) float64
valType ValueType
}{
// This metric is omitted in Go1.17+, see https://github.com/prometheus/client_golang/issues/842#issuecomment-861812034
desc: NewDesc(
memstatNamespace("gc_cpu_fraction"),
"The fraction of this program's available CPU time used by the GC since the program started.",
nil, nil,
),
eval: func(ms *runtime.MemStats) float64 { return ms.GCCPUFraction },
valType: GaugeValue,
})
return &goCollector{
base: newBaseGoCollector(),
msLast: &runtime.MemStats{},
msRead: runtime.ReadMemStats,
msMaxWait: time.Second,
msMaxAge: 5 * time.Minute,
msMetrics: msMetrics,
}
}
// Describe returns all descriptions of the collector.
func (c *goCollector) Describe(ch chan<- *Desc) {
c.base.Describe(ch)
for _, i := range c.msMetrics {
ch <- i.desc
}
}
// Collect returns the current state of all metrics of the collector.
func (c *goCollector) Collect(ch chan<- Metric) {
var (
ms = &runtime.MemStats{}
done = make(chan struct{})
)
// Start reading memstats first as it might take a while.
go func() {
c.msRead(ms)
c.msMtx.Lock()
c.msLast = ms
c.msLastTimestamp = time.Now()
c.msMtx.Unlock()
close(done)
}()
// Collect base non-memory metrics.
c.base.Collect(ch)
timer := time.NewTimer(c.msMaxWait)
select {
case <-done: // Our own ReadMemStats succeeded in time. Use it.
timer.Stop() // Important for high collection frequencies to not pile up timers.
c.msCollect(ch, ms)
return
case <-timer.C: // Time out, use last memstats if possible. Continue below.
}
c.msMtx.Lock()
if time.Since(c.msLastTimestamp) < c.msMaxAge {
// Last memstats are recent enough. Collect from them under the lock.
c.msCollect(ch, c.msLast)
c.msMtx.Unlock()
return
}
// If we are here, the last memstats are too old or don't exist. We have
// to wait until our own ReadMemStats finally completes. For that to
// happen, we have to release the lock.
c.msMtx.Unlock()
<-done
c.msCollect(ch, ms)
}
func (c *goCollector) msCollect(ch chan<- Metric, ms *runtime.MemStats) {
for _, i := range c.msMetrics {
ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
}
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build go1.17
// +build go1.17
package prometheus
import (
"fmt"
"math"
"runtime"
"runtime/metrics"
"strings"
"sync"
"github.com/prometheus/client_golang/prometheus/internal"
dto "github.com/prometheus/client_model/go"
"google.golang.org/protobuf/proto"
)
const (
// constants for strings referenced more than once.
goGCHeapTinyAllocsObjects = "/gc/heap/tiny/allocs:objects"
goGCHeapAllocsObjects = "/gc/heap/allocs:objects"
goGCHeapFreesObjects = "/gc/heap/frees:objects"
goGCHeapFreesBytes = "/gc/heap/frees:bytes"
goGCHeapAllocsBytes = "/gc/heap/allocs:bytes"
goGCHeapObjects = "/gc/heap/objects:objects"
goGCHeapGoalBytes = "/gc/heap/goal:bytes"
goMemoryClassesTotalBytes = "/memory/classes/total:bytes"
goMemoryClassesHeapObjectsBytes = "/memory/classes/heap/objects:bytes"
goMemoryClassesHeapUnusedBytes = "/memory/classes/heap/unused:bytes"
goMemoryClassesHeapReleasedBytes = "/memory/classes/heap/released:bytes"
goMemoryClassesHeapFreeBytes = "/memory/classes/heap/free:bytes"
goMemoryClassesHeapStacksBytes = "/memory/classes/heap/stacks:bytes"
goMemoryClassesOSStacksBytes = "/memory/classes/os-stacks:bytes"
goMemoryClassesMetadataMSpanInuseBytes = "/memory/classes/metadata/mspan/inuse:bytes"
goMemoryClassesMetadataMSPanFreeBytes = "/memory/classes/metadata/mspan/free:bytes"
goMemoryClassesMetadataMCacheInuseBytes = "/memory/classes/metadata/mcache/inuse:bytes"
goMemoryClassesMetadataMCacheFreeBytes = "/memory/classes/metadata/mcache/free:bytes"
goMemoryClassesProfilingBucketsBytes = "/memory/classes/profiling/buckets:bytes"
goMemoryClassesMetadataOtherBytes = "/memory/classes/metadata/other:bytes"
goMemoryClassesOtherBytes = "/memory/classes/other:bytes"
)
// rmNamesForMemStatsMetrics represents runtime/metrics names required to populate goRuntimeMemStats from like logic.
var rmNamesForMemStatsMetrics = []string{
goGCHeapTinyAllocsObjects,
goGCHeapAllocsObjects,
goGCHeapFreesObjects,
goGCHeapAllocsBytes,
goGCHeapObjects,
goGCHeapGoalBytes,
goMemoryClassesTotalBytes,
goMemoryClassesHeapObjectsBytes,
goMemoryClassesHeapUnusedBytes,
goMemoryClassesHeapReleasedBytes,
goMemoryClassesHeapFreeBytes,
goMemoryClassesHeapStacksBytes,
goMemoryClassesOSStacksBytes,
goMemoryClassesMetadataMSpanInuseBytes,
goMemoryClassesMetadataMSPanFreeBytes,
goMemoryClassesMetadataMCacheInuseBytes,
goMemoryClassesMetadataMCacheFreeBytes,
goMemoryClassesProfilingBucketsBytes,
goMemoryClassesMetadataOtherBytes,
goMemoryClassesOtherBytes,
}
func bestEffortLookupRM(lookup []string) []metrics.Description {
ret := make([]metrics.Description, 0, len(lookup))
for _, rm := range metrics.All() {
for _, m := range lookup {
if m == rm.Name {
ret = append(ret, rm)
}
}
}
return ret
}
type goCollector struct {
base baseGoCollector
// mu protects updates to all fields ensuring a consistent
// snapshot is always produced by Collect.
mu sync.Mutex
// Contains all samples that has to retrieved from runtime/metrics (not all of them will be exposed).
sampleBuf []metrics.Sample
// sampleMap allows lookup for MemStats metrics and runtime/metrics histograms for exact sums.
sampleMap map[string]*metrics.Sample
// rmExposedMetrics represents all runtime/metrics package metrics
// that were configured to be exposed.
rmExposedMetrics []collectorMetric
rmExactSumMapForHist map[string]string
// With Go 1.17, the runtime/metrics package was introduced.
// From that point on, metric names produced by the runtime/metrics
// package could be generated from runtime/metrics names. However,
// these differ from the old names for the same values.
//
// This field exists to export the same values under the old names
// as well.
msMetrics memStatsMetrics
msMetricsEnabled bool
}
type rmMetricDesc struct {
metrics.Description
}
func matchRuntimeMetricsRules(rules []internal.GoCollectorRule) []rmMetricDesc {
var descs []rmMetricDesc
for _, d := range metrics.All() {
var (
deny = true
desc rmMetricDesc
)
for _, r := range rules {
if !r.Matcher.MatchString(d.Name) {
continue
}
deny = r.Deny
}
if deny {
continue
}
desc.Description = d
descs = append(descs, desc)
}
return descs
}
func defaultGoCollectorOptions() internal.GoCollectorOptions {
return internal.GoCollectorOptions{
RuntimeMetricSumForHist: map[string]string{
"/gc/heap/allocs-by-size:bytes": goGCHeapAllocsBytes,
"/gc/heap/frees-by-size:bytes": goGCHeapFreesBytes,
},
RuntimeMetricRules: []internal.GoCollectorRule{
// Recommended metrics we want by default from runtime/metrics.
{Matcher: internal.GoCollectorDefaultRuntimeMetrics},
},
}
}
// NewGoCollector is the obsolete version of collectors.NewGoCollector.
// See there for documentation.
//
// Deprecated: Use collectors.NewGoCollector instead.
func NewGoCollector(opts ...func(o *internal.GoCollectorOptions)) Collector {
opt := defaultGoCollectorOptions()
for _, o := range opts {
o(&opt)
}
exposedDescriptions := matchRuntimeMetricsRules(opt.RuntimeMetricRules)
// Collect all histogram samples so that we can get their buckets.
// The API guarantees that the buckets are always fixed for the lifetime
// of the process.
var histograms []metrics.Sample
for _, d := range exposedDescriptions {
if d.Kind == metrics.KindFloat64Histogram {
histograms = append(histograms, metrics.Sample{Name: d.Name})
}
}
if len(histograms) > 0 {
metrics.Read(histograms)
}
bucketsMap := make(map[string][]float64)
for i := range histograms {
bucketsMap[histograms[i].Name] = histograms[i].Value.Float64Histogram().Buckets
}
// Generate a collector for each exposed runtime/metrics metric.
metricSet := make([]collectorMetric, 0, len(exposedDescriptions))
// SampleBuf is used for reading from runtime/metrics.
// We are assuming the largest case to have stable pointers for sampleMap purposes.
sampleBuf := make([]metrics.Sample, 0, len(exposedDescriptions)+len(opt.RuntimeMetricSumForHist)+len(rmNamesForMemStatsMetrics))
sampleMap := make(map[string]*metrics.Sample, len(exposedDescriptions))
for _, d := range exposedDescriptions {
namespace, subsystem, name, ok := internal.RuntimeMetricsToProm(&d.Description)
if !ok {
// Just ignore this metric; we can't do anything with it here.
// If a user decides to use the latest version of Go, we don't want
// to fail here. This condition is tested in TestExpectedRuntimeMetrics.
continue
}
help := attachOriginalName(d.Description.Description, d.Name)
sampleBuf = append(sampleBuf, metrics.Sample{Name: d.Name})
sampleMap[d.Name] = &sampleBuf[len(sampleBuf)-1]
var m collectorMetric
if d.Kind == metrics.KindFloat64Histogram {
_, hasSum := opt.RuntimeMetricSumForHist[d.Name]
unit := d.Name[strings.IndexRune(d.Name, ':')+1:]
m = newBatchHistogram(
NewDesc(
BuildFQName(namespace, subsystem, name),
help,
nil,
nil,
),
internal.RuntimeMetricsBucketsForUnit(bucketsMap[d.Name], unit),
hasSum,
)
} else if d.Cumulative {
m = NewCounter(CounterOpts{
Namespace: namespace,
Subsystem: subsystem,
Name: name,
Help: help,
},
)
} else {
m = NewGauge(GaugeOpts{
Namespace: namespace,
Subsystem: subsystem,
Name: name,
Help: help,
})
}
metricSet = append(metricSet, m)
}
// Add exact sum metrics to sampleBuf if not added before.
for _, h := range histograms {
sumMetric, ok := opt.RuntimeMetricSumForHist[h.Name]
if !ok {
continue
}
if _, ok := sampleMap[sumMetric]; ok {
continue
}
sampleBuf = append(sampleBuf, metrics.Sample{Name: sumMetric})
sampleMap[sumMetric] = &sampleBuf[len(sampleBuf)-1]
}
var (
msMetrics memStatsMetrics
msDescriptions []metrics.Description
)
if !opt.DisableMemStatsLikeMetrics {
msMetrics = goRuntimeMemStats()
msDescriptions = bestEffortLookupRM(rmNamesForMemStatsMetrics)
// Check if metric was not exposed before and if not, add to sampleBuf.
for _, mdDesc := range msDescriptions {
if _, ok := sampleMap[mdDesc.Name]; ok {
continue
}
sampleBuf = append(sampleBuf, metrics.Sample{Name: mdDesc.Name})
sampleMap[mdDesc.Name] = &sampleBuf[len(sampleBuf)-1]
}
}
return &goCollector{
base: newBaseGoCollector(),
sampleBuf: sampleBuf,
sampleMap: sampleMap,
rmExposedMetrics: metricSet,
rmExactSumMapForHist: opt.RuntimeMetricSumForHist,
msMetrics: msMetrics,
msMetricsEnabled: !opt.DisableMemStatsLikeMetrics,
}
}
func attachOriginalName(desc, origName string) string {
return fmt.Sprintf("%s Sourced from %s.", desc, origName)
}
// Describe returns all descriptions of the collector.
func (c *goCollector) Describe(ch chan<- *Desc) {
c.base.Describe(ch)
for _, i := range c.msMetrics {
ch <- i.desc
}
for _, m := range c.rmExposedMetrics {
ch <- m.Desc()
}
}
// Collect returns the current state of all metrics of the collector.
func (c *goCollector) Collect(ch chan<- Metric) {
// Collect base non-memory metrics.
c.base.Collect(ch)
if len(c.sampleBuf) == 0 {
return
}
// Collect must be thread-safe, so prevent concurrent use of
// sampleBuf elements. Just read into sampleBuf but write all the data
// we get into our Metrics or MemStats.
//
// This lock also ensures that the Metrics we send out are all from
// the same updates, ensuring their mutual consistency insofar as
// is guaranteed by the runtime/metrics package.
//
// N.B. This locking is heavy-handed, but Collect is expected to be called
// relatively infrequently. Also the core operation here, metrics.Read,
// is fast (O(tens of microseconds)) so contention should certainly be
// low, though channel operations and any allocations may add to that.
c.mu.Lock()
defer c.mu.Unlock()
// Populate runtime/metrics sample buffer.
metrics.Read(c.sampleBuf)
// Collect all our runtime/metrics user chose to expose from sampleBuf (if any).
for i, metric := range c.rmExposedMetrics {
// We created samples for exposed metrics first in order, so indexes match.
sample := c.sampleBuf[i]
// N.B. switch on concrete type because it's significantly more efficient
// than checking for the Counter and Gauge interface implementations. In
// this case, we control all the types here.
switch m := metric.(type) {
case *counter:
// Guard against decreases. This should never happen, but a failure
// to do so will result in a panic, which is a harsh consequence for
// a metrics collection bug.
v0, v1 := m.get(), unwrapScalarRMValue(sample.Value)
if v1 > v0 {
m.Add(unwrapScalarRMValue(sample.Value) - m.get())
}
m.Collect(ch)
case *gauge:
m.Set(unwrapScalarRMValue(sample.Value))
m.Collect(ch)
case *batchHistogram:
m.update(sample.Value.Float64Histogram(), c.exactSumFor(sample.Name))
m.Collect(ch)
default:
panic("unexpected metric type")
}
}
if c.msMetricsEnabled {
// ms is a dummy MemStats that we populate ourselves so that we can
// populate the old metrics from it if goMemStatsCollection is enabled.
var ms runtime.MemStats
memStatsFromRM(&ms, c.sampleMap)
for _, i := range c.msMetrics {
ch <- MustNewConstMetric(i.desc, i.valType, i.eval(&ms))
}
}
}
// unwrapScalarRMValue unwraps a runtime/metrics value that is assumed
// to be scalar and returns the equivalent float64 value. Panics if the
// value is not scalar.
func unwrapScalarRMValue(v metrics.Value) float64 {
switch v.Kind() {
case metrics.KindUint64:
return float64(v.Uint64())
case metrics.KindFloat64:
return v.Float64()
case metrics.KindBad:
// Unsupported metric.
//
// This should never happen because we always populate our metric
// set from the runtime/metrics package.
panic("unexpected bad kind metric")
default:
// Unsupported metric kind.
//
// This should never happen because we check for this during initialization
// and flag and filter metrics whose kinds we don't understand.
panic(fmt.Sprintf("unexpected unsupported metric: %v", v.Kind()))
}
}
// exactSumFor takes a runtime/metrics metric name (that is assumed to
// be of kind KindFloat64Histogram) and returns its exact sum and whether
// its exact sum exists.
//
// The runtime/metrics API for histograms doesn't currently expose exact
// sums, but some of the other metrics are in fact exact sums of histograms.
func (c *goCollector) exactSumFor(rmName string) float64 {
sumName, ok := c.rmExactSumMapForHist[rmName]
if !ok {
return 0
}
s, ok := c.sampleMap[sumName]
if !ok {
return 0
}
return unwrapScalarRMValue(s.Value)
}
func memStatsFromRM(ms *runtime.MemStats, rm map[string]*metrics.Sample) {
lookupOrZero := func(name string) uint64 {
if s, ok := rm[name]; ok {
return s.Value.Uint64()
}
return 0
}
// Currently, MemStats adds tiny alloc count to both Mallocs AND Frees.
// The reason for this is because MemStats couldn't be extended at the time
// but there was a desire to have Mallocs at least be a little more representative,
// while having Mallocs - Frees still represent a live object count.
// Unfortunately, MemStats doesn't actually export a large allocation count,
// so it's impossible to pull this number out directly.
tinyAllocs := lookupOrZero(goGCHeapTinyAllocsObjects)
ms.Mallocs = lookupOrZero(goGCHeapAllocsObjects) + tinyAllocs
ms.Frees = lookupOrZero(goGCHeapFreesObjects) + tinyAllocs
ms.TotalAlloc = lookupOrZero(goGCHeapAllocsBytes)
ms.Sys = lookupOrZero(goMemoryClassesTotalBytes)
ms.Lookups = 0 // Already always zero.
ms.HeapAlloc = lookupOrZero(goMemoryClassesHeapObjectsBytes)
ms.Alloc = ms.HeapAlloc
ms.HeapInuse = ms.HeapAlloc + lookupOrZero(goMemoryClassesHeapUnusedBytes)
ms.HeapReleased = lookupOrZero(goMemoryClassesHeapReleasedBytes)
ms.HeapIdle = ms.HeapReleased + lookupOrZero(goMemoryClassesHeapFreeBytes)
ms.HeapSys = ms.HeapInuse + ms.HeapIdle
ms.HeapObjects = lookupOrZero(goGCHeapObjects)
ms.StackInuse = lookupOrZero(goMemoryClassesHeapStacksBytes)
ms.StackSys = ms.StackInuse + lookupOrZero(goMemoryClassesOSStacksBytes)
ms.MSpanInuse = lookupOrZero(goMemoryClassesMetadataMSpanInuseBytes)
ms.MSpanSys = ms.MSpanInuse + lookupOrZero(goMemoryClassesMetadataMSPanFreeBytes)
ms.MCacheInuse = lookupOrZero(goMemoryClassesMetadataMCacheInuseBytes)
ms.MCacheSys = ms.MCacheInuse + lookupOrZero(goMemoryClassesMetadataMCacheFreeBytes)
ms.BuckHashSys = lookupOrZero(goMemoryClassesProfilingBucketsBytes)
ms.GCSys = lookupOrZero(goMemoryClassesMetadataOtherBytes)
ms.OtherSys = lookupOrZero(goMemoryClassesOtherBytes)
ms.NextGC = lookupOrZero(goGCHeapGoalBytes)
// N.B. GCCPUFraction is intentionally omitted. This metric is not useful,
// and often misleading due to the fact that it's an average over the lifetime
// of the process.
// See https://github.com/prometheus/client_golang/issues/842#issuecomment-861812034
// for more details.
ms.GCCPUFraction = 0
}
// batchHistogram is a mutable histogram that is updated
// in batches.
type batchHistogram struct {
selfCollector
// Static fields updated only once.
desc *Desc
hasSum bool
// Because this histogram operates in batches, it just uses a
// single mutex for everything. updates are always serialized
// but Write calls may operate concurrently with updates.
// Contention between these two sources should be rare.
mu sync.Mutex
buckets []float64 // Inclusive lower bounds, like runtime/metrics.
counts []uint64
sum float64 // Used if hasSum is true.
}
// newBatchHistogram creates a new batch histogram value with the given
// Desc, buckets, and whether or not it has an exact sum available.
//
// buckets must always be from the runtime/metrics package, following
// the same conventions.
func newBatchHistogram(desc *Desc, buckets []float64, hasSum bool) *batchHistogram {
// We need to remove -Inf values. runtime/metrics keeps them around.
// But -Inf bucket should not be allowed for prometheus histograms.
if buckets[0] == math.Inf(-1) {
buckets = buckets[1:]
}
h := &batchHistogram{
desc: desc,
buckets: buckets,
// Because buckets follows runtime/metrics conventions, there's
// 1 more value in the buckets list than there are buckets represented,
// because in runtime/metrics, the bucket values represent *boundaries*,
// and non-Inf boundaries are inclusive lower bounds for that bucket.
counts: make([]uint64, len(buckets)-1),
hasSum: hasSum,
}
h.init(h)
return h
}
// update updates the batchHistogram from a runtime/metrics histogram.
//
// sum must be provided if the batchHistogram was created to have an exact sum.
// h.buckets must be a strict subset of his.Buckets.
func (h *batchHistogram) update(his *metrics.Float64Histogram, sum float64) {
counts, buckets := his.Counts, his.Buckets
h.mu.Lock()
defer h.mu.Unlock()
// Clear buckets.
for i := range h.counts {
h.counts[i] = 0
}
// Copy and reduce buckets.
var j int
for i, count := range counts {
h.counts[j] += count
if buckets[i+1] == h.buckets[j+1] {
j++
}
}
if h.hasSum {
h.sum = sum
}
}
func (h *batchHistogram) Desc() *Desc {
return h.desc
}
func (h *batchHistogram) Write(out *dto.Metric) error {
h.mu.Lock()
defer h.mu.Unlock()
sum := float64(0)
if h.hasSum {
sum = h.sum
}
dtoBuckets := make([]*dto.Bucket, 0, len(h.counts))
totalCount := uint64(0)
for i, count := range h.counts {
totalCount += count
if !h.hasSum {
if count != 0 {
// N.B. This computed sum is an underestimate.
sum += h.buckets[i] * float64(count)
}
}
// Skip the +Inf bucket, but only for the bucket list.
// It must still count for sum and totalCount.
if math.IsInf(h.buckets[i+1], 1) {
break
}
// Float64Histogram's upper bound is exclusive, so make it inclusive
// by obtaining the next float64 value down, in order.
upperBound := math.Nextafter(h.buckets[i+1], h.buckets[i])
dtoBuckets = append(dtoBuckets, &dto.Bucket{
CumulativeCount: proto.Uint64(totalCount),
UpperBound: proto.Float64(upperBound),
})
}
out.Histogram = &dto.Histogram{
Bucket: dtoBuckets,
SampleCount: proto.Uint64(totalCount),
SampleSum: proto.Float64(sum),
}
return nil
}

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@ -0,0 +1,60 @@
// Copyright (c) 2015 Björn Rabenstein
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// The code in this package is copy/paste to avoid a dependency. Hence this file
// carries the copyright of the original repo.
// https://github.com/beorn7/floats
package internal
import (
"math"
)
// minNormalFloat64 is the smallest positive normal value of type float64.
var minNormalFloat64 = math.Float64frombits(0x0010000000000000)
// AlmostEqualFloat64 returns true if a and b are equal within a relative error
// of epsilon. See http://floating-point-gui.de/errors/comparison/ for the
// details of the applied method.
func AlmostEqualFloat64(a, b, epsilon float64) bool {
if a == b {
return true
}
absA := math.Abs(a)
absB := math.Abs(b)
diff := math.Abs(a - b)
if a == 0 || b == 0 || absA+absB < minNormalFloat64 {
return diff < epsilon*minNormalFloat64
}
return diff/math.Min(absA+absB, math.MaxFloat64) < epsilon
}
// AlmostEqualFloat64s is the slice form of AlmostEqualFloat64.
func AlmostEqualFloat64s(a, b []float64, epsilon float64) bool {
if len(a) != len(b) {
return false
}
for i := range a {
if !AlmostEqualFloat64(a[i], b[i], epsilon) {
return false
}
}
return true
}

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@ -0,0 +1,655 @@
// Copyright 2022 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// It provides tools to compare sequences of strings and generate textual diffs.
//
// Maintaining `GetUnifiedDiffString` here because original repository
// (https://github.com/pmezard/go-difflib) is no longer maintained.
package internal
import (
"bufio"
"bytes"
"fmt"
"io"
"strconv"
"strings"
)
func minInt(a, b int) int {
if a < b {
return a
}
return b
}
func maxInt(a, b int) int {
if a > b {
return a
}
return b
}
func calculateRatio(matches, length int) float64 {
if length > 0 {
return 2.0 * float64(matches) / float64(length)
}
return 1.0
}
type Match struct {
A int
B int
Size int
}
type OpCode struct {
Tag byte
I1 int
I2 int
J1 int
J2 int
}
// SequenceMatcher compares sequence of strings. The basic
// algorithm predates, and is a little fancier than, an algorithm
// published in the late 1980's by Ratcliff and Obershelp under the
// hyperbolic name "gestalt pattern matching". The basic idea is to find
// the longest contiguous matching subsequence that contains no "junk"
// elements (R-O doesn't address junk). The same idea is then applied
// recursively to the pieces of the sequences to the left and to the right
// of the matching subsequence. This does not yield minimal edit
// sequences, but does tend to yield matches that "look right" to people.
//
// SequenceMatcher tries to compute a "human-friendly diff" between two
// sequences. Unlike e.g. UNIX(tm) diff, the fundamental notion is the
// longest *contiguous* & junk-free matching subsequence. That's what
// catches peoples' eyes. The Windows(tm) windiff has another interesting
// notion, pairing up elements that appear uniquely in each sequence.
// That, and the method here, appear to yield more intuitive difference
// reports than does diff. This method appears to be the least vulnerable
// to synching up on blocks of "junk lines", though (like blank lines in
// ordinary text files, or maybe "<P>" lines in HTML files). That may be
// because this is the only method of the 3 that has a *concept* of
// "junk" <wink>.
//
// Timing: Basic R-O is cubic time worst case and quadratic time expected
// case. SequenceMatcher is quadratic time for the worst case and has
// expected-case behavior dependent in a complicated way on how many
// elements the sequences have in common; best case time is linear.
type SequenceMatcher struct {
a []string
b []string
b2j map[string][]int
IsJunk func(string) bool
autoJunk bool
bJunk map[string]struct{}
matchingBlocks []Match
fullBCount map[string]int
bPopular map[string]struct{}
opCodes []OpCode
}
func NewMatcher(a, b []string) *SequenceMatcher {
m := SequenceMatcher{autoJunk: true}
m.SetSeqs(a, b)
return &m
}
func NewMatcherWithJunk(a, b []string, autoJunk bool,
isJunk func(string) bool,
) *SequenceMatcher {
m := SequenceMatcher{IsJunk: isJunk, autoJunk: autoJunk}
m.SetSeqs(a, b)
return &m
}
// Set two sequences to be compared.
func (m *SequenceMatcher) SetSeqs(a, b []string) {
m.SetSeq1(a)
m.SetSeq2(b)
}
// Set the first sequence to be compared. The second sequence to be compared is
// not changed.
//
// SequenceMatcher computes and caches detailed information about the second
// sequence, so if you want to compare one sequence S against many sequences,
// use .SetSeq2(s) once and call .SetSeq1(x) repeatedly for each of the other
// sequences.
//
// See also SetSeqs() and SetSeq2().
func (m *SequenceMatcher) SetSeq1(a []string) {
if &a == &m.a {
return
}
m.a = a
m.matchingBlocks = nil
m.opCodes = nil
}
// Set the second sequence to be compared. The first sequence to be compared is
// not changed.
func (m *SequenceMatcher) SetSeq2(b []string) {
if &b == &m.b {
return
}
m.b = b
m.matchingBlocks = nil
m.opCodes = nil
m.fullBCount = nil
m.chainB()
}
func (m *SequenceMatcher) chainB() {
// Populate line -> index mapping
b2j := map[string][]int{}
for i, s := range m.b {
indices := b2j[s]
indices = append(indices, i)
b2j[s] = indices
}
// Purge junk elements
m.bJunk = map[string]struct{}{}
if m.IsJunk != nil {
junk := m.bJunk
for s := range b2j {
if m.IsJunk(s) {
junk[s] = struct{}{}
}
}
for s := range junk {
delete(b2j, s)
}
}
// Purge remaining popular elements
popular := map[string]struct{}{}
n := len(m.b)
if m.autoJunk && n >= 200 {
ntest := n/100 + 1
for s, indices := range b2j {
if len(indices) > ntest {
popular[s] = struct{}{}
}
}
for s := range popular {
delete(b2j, s)
}
}
m.bPopular = popular
m.b2j = b2j
}
func (m *SequenceMatcher) isBJunk(s string) bool {
_, ok := m.bJunk[s]
return ok
}
// Find longest matching block in a[alo:ahi] and b[blo:bhi].
//
// If IsJunk is not defined:
//
// Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where
//
// alo <= i <= i+k <= ahi
// blo <= j <= j+k <= bhi
//
// and for all (i',j',k') meeting those conditions,
//
// k >= k'
// i <= i'
// and if i == i', j <= j'
//
// In other words, of all maximal matching blocks, return one that
// starts earliest in a, and of all those maximal matching blocks that
// start earliest in a, return the one that starts earliest in b.
//
// If IsJunk is defined, first the longest matching block is
// determined as above, but with the additional restriction that no
// junk element appears in the block. Then that block is extended as
// far as possible by matching (only) junk elements on both sides. So
// the resulting block never matches on junk except as identical junk
// happens to be adjacent to an "interesting" match.
//
// If no blocks match, return (alo, blo, 0).
func (m *SequenceMatcher) findLongestMatch(alo, ahi, blo, bhi int) Match {
// CAUTION: stripping common prefix or suffix would be incorrect.
// E.g.,
// ab
// acab
// Longest matching block is "ab", but if common prefix is
// stripped, it's "a" (tied with "b"). UNIX(tm) diff does so
// strip, so ends up claiming that ab is changed to acab by
// inserting "ca" in the middle. That's minimal but unintuitive:
// "it's obvious" that someone inserted "ac" at the front.
// Windiff ends up at the same place as diff, but by pairing up
// the unique 'b's and then matching the first two 'a's.
besti, bestj, bestsize := alo, blo, 0
// find longest junk-free match
// during an iteration of the loop, j2len[j] = length of longest
// junk-free match ending with a[i-1] and b[j]
j2len := map[int]int{}
for i := alo; i != ahi; i++ {
// look at all instances of a[i] in b; note that because
// b2j has no junk keys, the loop is skipped if a[i] is junk
newj2len := map[int]int{}
for _, j := range m.b2j[m.a[i]] {
// a[i] matches b[j]
if j < blo {
continue
}
if j >= bhi {
break
}
k := j2len[j-1] + 1
newj2len[j] = k
if k > bestsize {
besti, bestj, bestsize = i-k+1, j-k+1, k
}
}
j2len = newj2len
}
// Extend the best by non-junk elements on each end. In particular,
// "popular" non-junk elements aren't in b2j, which greatly speeds
// the inner loop above, but also means "the best" match so far
// doesn't contain any junk *or* popular non-junk elements.
for besti > alo && bestj > blo && !m.isBJunk(m.b[bestj-1]) &&
m.a[besti-1] == m.b[bestj-1] {
besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
}
for besti+bestsize < ahi && bestj+bestsize < bhi &&
!m.isBJunk(m.b[bestj+bestsize]) &&
m.a[besti+bestsize] == m.b[bestj+bestsize] {
bestsize++
}
// Now that we have a wholly interesting match (albeit possibly
// empty!), we may as well suck up the matching junk on each
// side of it too. Can't think of a good reason not to, and it
// saves post-processing the (possibly considerable) expense of
// figuring out what to do with it. In the case of an empty
// interesting match, this is clearly the right thing to do,
// because no other kind of match is possible in the regions.
for besti > alo && bestj > blo && m.isBJunk(m.b[bestj-1]) &&
m.a[besti-1] == m.b[bestj-1] {
besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
}
for besti+bestsize < ahi && bestj+bestsize < bhi &&
m.isBJunk(m.b[bestj+bestsize]) &&
m.a[besti+bestsize] == m.b[bestj+bestsize] {
bestsize++
}
return Match{A: besti, B: bestj, Size: bestsize}
}
// Return list of triples describing matching subsequences.
//
// Each triple is of the form (i, j, n), and means that
// a[i:i+n] == b[j:j+n]. The triples are monotonically increasing in
// i and in j. It's also guaranteed that if (i, j, n) and (i', j', n') are
// adjacent triples in the list, and the second is not the last triple in the
// list, then i+n != i' or j+n != j'. IOW, adjacent triples never describe
// adjacent equal blocks.
//
// The last triple is a dummy, (len(a), len(b), 0), and is the only
// triple with n==0.
func (m *SequenceMatcher) GetMatchingBlocks() []Match {
if m.matchingBlocks != nil {
return m.matchingBlocks
}
var matchBlocks func(alo, ahi, blo, bhi int, matched []Match) []Match
matchBlocks = func(alo, ahi, blo, bhi int, matched []Match) []Match {
match := m.findLongestMatch(alo, ahi, blo, bhi)
i, j, k := match.A, match.B, match.Size
if match.Size > 0 {
if alo < i && blo < j {
matched = matchBlocks(alo, i, blo, j, matched)
}
matched = append(matched, match)
if i+k < ahi && j+k < bhi {
matched = matchBlocks(i+k, ahi, j+k, bhi, matched)
}
}
return matched
}
matched := matchBlocks(0, len(m.a), 0, len(m.b), nil)
// It's possible that we have adjacent equal blocks in the
// matching_blocks list now.
nonAdjacent := []Match{}
i1, j1, k1 := 0, 0, 0
for _, b := range matched {
// Is this block adjacent to i1, j1, k1?
i2, j2, k2 := b.A, b.B, b.Size
if i1+k1 == i2 && j1+k1 == j2 {
// Yes, so collapse them -- this just increases the length of
// the first block by the length of the second, and the first
// block so lengthened remains the block to compare against.
k1 += k2
} else {
// Not adjacent. Remember the first block (k1==0 means it's
// the dummy we started with), and make the second block the
// new block to compare against.
if k1 > 0 {
nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
}
i1, j1, k1 = i2, j2, k2
}
}
if k1 > 0 {
nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
}
nonAdjacent = append(nonAdjacent, Match{len(m.a), len(m.b), 0})
m.matchingBlocks = nonAdjacent
return m.matchingBlocks
}
// Return list of 5-tuples describing how to turn a into b.
//
// Each tuple is of the form (tag, i1, i2, j1, j2). The first tuple
// has i1 == j1 == 0, and remaining tuples have i1 == the i2 from the
// tuple preceding it, and likewise for j1 == the previous j2.
//
// The tags are characters, with these meanings:
//
// 'r' (replace): a[i1:i2] should be replaced by b[j1:j2]
//
// 'd' (delete): a[i1:i2] should be deleted, j1==j2 in this case.
//
// 'i' (insert): b[j1:j2] should be inserted at a[i1:i1], i1==i2 in this case.
//
// 'e' (equal): a[i1:i2] == b[j1:j2]
func (m *SequenceMatcher) GetOpCodes() []OpCode {
if m.opCodes != nil {
return m.opCodes
}
i, j := 0, 0
matching := m.GetMatchingBlocks()
opCodes := make([]OpCode, 0, len(matching))
for _, m := range matching {
// invariant: we've pumped out correct diffs to change
// a[:i] into b[:j], and the next matching block is
// a[ai:ai+size] == b[bj:bj+size]. So we need to pump
// out a diff to change a[i:ai] into b[j:bj], pump out
// the matching block, and move (i,j) beyond the match
ai, bj, size := m.A, m.B, m.Size
tag := byte(0)
if i < ai && j < bj {
tag = 'r'
} else if i < ai {
tag = 'd'
} else if j < bj {
tag = 'i'
}
if tag > 0 {
opCodes = append(opCodes, OpCode{tag, i, ai, j, bj})
}
i, j = ai+size, bj+size
// the list of matching blocks is terminated by a
// sentinel with size 0
if size > 0 {
opCodes = append(opCodes, OpCode{'e', ai, i, bj, j})
}
}
m.opCodes = opCodes
return m.opCodes
}
// Isolate change clusters by eliminating ranges with no changes.
//
// Return a generator of groups with up to n lines of context.
// Each group is in the same format as returned by GetOpCodes().
func (m *SequenceMatcher) GetGroupedOpCodes(n int) [][]OpCode {
if n < 0 {
n = 3
}
codes := m.GetOpCodes()
if len(codes) == 0 {
codes = []OpCode{{'e', 0, 1, 0, 1}}
}
// Fixup leading and trailing groups if they show no changes.
if codes[0].Tag == 'e' {
c := codes[0]
i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
codes[0] = OpCode{c.Tag, maxInt(i1, i2-n), i2, maxInt(j1, j2-n), j2}
}
if codes[len(codes)-1].Tag == 'e' {
c := codes[len(codes)-1]
i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
codes[len(codes)-1] = OpCode{c.Tag, i1, minInt(i2, i1+n), j1, minInt(j2, j1+n)}
}
nn := n + n
groups := [][]OpCode{}
group := []OpCode{}
for _, c := range codes {
i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
// End the current group and start a new one whenever
// there is a large range with no changes.
if c.Tag == 'e' && i2-i1 > nn {
group = append(group, OpCode{
c.Tag, i1, minInt(i2, i1+n),
j1, minInt(j2, j1+n),
})
groups = append(groups, group)
group = []OpCode{}
i1, j1 = maxInt(i1, i2-n), maxInt(j1, j2-n)
}
group = append(group, OpCode{c.Tag, i1, i2, j1, j2})
}
if len(group) > 0 && !(len(group) == 1 && group[0].Tag == 'e') {
groups = append(groups, group)
}
return groups
}
// Return a measure of the sequences' similarity (float in [0,1]).
//
// Where T is the total number of elements in both sequences, and
// M is the number of matches, this is 2.0*M / T.
// Note that this is 1 if the sequences are identical, and 0 if
// they have nothing in common.
//
// .Ratio() is expensive to compute if you haven't already computed
// .GetMatchingBlocks() or .GetOpCodes(), in which case you may
// want to try .QuickRatio() or .RealQuickRation() first to get an
// upper bound.
func (m *SequenceMatcher) Ratio() float64 {
matches := 0
for _, m := range m.GetMatchingBlocks() {
matches += m.Size
}
return calculateRatio(matches, len(m.a)+len(m.b))
}
// Return an upper bound on ratio() relatively quickly.
//
// This isn't defined beyond that it is an upper bound on .Ratio(), and
// is faster to compute.
func (m *SequenceMatcher) QuickRatio() float64 {
// viewing a and b as multisets, set matches to the cardinality
// of their intersection; this counts the number of matches
// without regard to order, so is clearly an upper bound
if m.fullBCount == nil {
m.fullBCount = map[string]int{}
for _, s := range m.b {
m.fullBCount[s]++
}
}
// avail[x] is the number of times x appears in 'b' less the
// number of times we've seen it in 'a' so far ... kinda
avail := map[string]int{}
matches := 0
for _, s := range m.a {
n, ok := avail[s]
if !ok {
n = m.fullBCount[s]
}
avail[s] = n - 1
if n > 0 {
matches++
}
}
return calculateRatio(matches, len(m.a)+len(m.b))
}
// Return an upper bound on ratio() very quickly.
//
// This isn't defined beyond that it is an upper bound on .Ratio(), and
// is faster to compute than either .Ratio() or .QuickRatio().
func (m *SequenceMatcher) RealQuickRatio() float64 {
la, lb := len(m.a), len(m.b)
return calculateRatio(minInt(la, lb), la+lb)
}
// Convert range to the "ed" format
func formatRangeUnified(start, stop int) string {
// Per the diff spec at http://www.unix.org/single_unix_specification/
beginning := start + 1 // lines start numbering with one
length := stop - start
if length == 1 {
return strconv.Itoa(beginning)
}
if length == 0 {
beginning-- // empty ranges begin at line just before the range
}
return fmt.Sprintf("%d,%d", beginning, length)
}
// Unified diff parameters
type UnifiedDiff struct {
A []string // First sequence lines
FromFile string // First file name
FromDate string // First file time
B []string // Second sequence lines
ToFile string // Second file name
ToDate string // Second file time
Eol string // Headers end of line, defaults to LF
Context int // Number of context lines
}
// Compare two sequences of lines; generate the delta as a unified diff.
//
// Unified diffs are a compact way of showing line changes and a few
// lines of context. The number of context lines is set by 'n' which
// defaults to three.
//
// By default, the diff control lines (those with ---, +++, or @@) are
// created with a trailing newline. This is helpful so that inputs
// created from file.readlines() result in diffs that are suitable for
// file.writelines() since both the inputs and outputs have trailing
// newlines.
//
// For inputs that do not have trailing newlines, set the lineterm
// argument to "" so that the output will be uniformly newline free.
//
// The unidiff format normally has a header for filenames and modification
// times. Any or all of these may be specified using strings for
// 'fromfile', 'tofile', 'fromfiledate', and 'tofiledate'.
// The modification times are normally expressed in the ISO 8601 format.
func WriteUnifiedDiff(writer io.Writer, diff UnifiedDiff) error {
buf := bufio.NewWriter(writer)
defer buf.Flush()
wf := func(format string, args ...interface{}) error {
_, err := buf.WriteString(fmt.Sprintf(format, args...))
return err
}
ws := func(s string) error {
_, err := buf.WriteString(s)
return err
}
if len(diff.Eol) == 0 {
diff.Eol = "\n"
}
started := false
m := NewMatcher(diff.A, diff.B)
for _, g := range m.GetGroupedOpCodes(diff.Context) {
if !started {
started = true
fromDate := ""
if len(diff.FromDate) > 0 {
fromDate = "\t" + diff.FromDate
}
toDate := ""
if len(diff.ToDate) > 0 {
toDate = "\t" + diff.ToDate
}
if diff.FromFile != "" || diff.ToFile != "" {
err := wf("--- %s%s%s", diff.FromFile, fromDate, diff.Eol)
if err != nil {
return err
}
err = wf("+++ %s%s%s", diff.ToFile, toDate, diff.Eol)
if err != nil {
return err
}
}
}
first, last := g[0], g[len(g)-1]
range1 := formatRangeUnified(first.I1, last.I2)
range2 := formatRangeUnified(first.J1, last.J2)
if err := wf("@@ -%s +%s @@%s", range1, range2, diff.Eol); err != nil {
return err
}
for _, c := range g {
i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
if c.Tag == 'e' {
for _, line := range diff.A[i1:i2] {
if err := ws(" " + line); err != nil {
return err
}
}
continue
}
if c.Tag == 'r' || c.Tag == 'd' {
for _, line := range diff.A[i1:i2] {
if err := ws("-" + line); err != nil {
return err
}
}
}
if c.Tag == 'r' || c.Tag == 'i' {
for _, line := range diff.B[j1:j2] {
if err := ws("+" + line); err != nil {
return err
}
}
}
}
}
return nil
}
// Like WriteUnifiedDiff but returns the diff a string.
func GetUnifiedDiffString(diff UnifiedDiff) (string, error) {
w := &bytes.Buffer{}
err := WriteUnifiedDiff(w, diff)
return w.String(), err
}
// Split a string on "\n" while preserving them. The output can be used
// as input for UnifiedDiff and ContextDiff structures.
func SplitLines(s string) []string {
lines := strings.SplitAfter(s, "\n")
lines[len(lines)-1] += "\n"
return lines
}

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package internal
import "regexp"
type GoCollectorRule struct {
Matcher *regexp.Regexp
Deny bool
}
// GoCollectorOptions should not be used be directly by anything, except `collectors` package.
// Use it via collectors package instead. See issue
// https://github.com/prometheus/client_golang/issues/1030.
//
// This is internal, so external users only can use it via `collector.WithGoCollector*` methods
type GoCollectorOptions struct {
DisableMemStatsLikeMetrics bool
RuntimeMetricSumForHist map[string]string
RuntimeMetricRules []GoCollectorRule
}
var GoCollectorDefaultRuntimeMetrics = regexp.MustCompile(`/gc/gogc:percent|/gc/gomemlimit:bytes|/sched/gomaxprocs:threads`)

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// Copyright 2021 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build go1.17
// +build go1.17
package internal
import (
"math"
"path"
"runtime/metrics"
"strings"
"github.com/prometheus/common/model"
)
// RuntimeMetricsToProm produces a Prometheus metric name from a runtime/metrics
// metric description and validates whether the metric is suitable for integration
// with Prometheus.
//
// Returns false if a name could not be produced, or if Prometheus does not understand
// the runtime/metrics Kind.
//
// Note that the main reason a name couldn't be produced is if the runtime/metrics
// package exports a name with characters outside the valid Prometheus metric name
// character set. This is theoretically possible, but should never happen in practice.
// Still, don't rely on it.
func RuntimeMetricsToProm(d *metrics.Description) (string, string, string, bool) {
namespace := "go"
comp := strings.SplitN(d.Name, ":", 2)
key := comp[0]
unit := comp[1]
// The last path element in the key is the name,
// the rest is the subsystem.
subsystem := path.Dir(key[1:] /* remove leading / */)
name := path.Base(key)
// subsystem is translated by replacing all / and - with _.
subsystem = strings.ReplaceAll(subsystem, "/", "_")
subsystem = strings.ReplaceAll(subsystem, "-", "_")
// unit is translated assuming that the unit contains no
// non-ASCII characters.
unit = strings.ReplaceAll(unit, "-", "_")
unit = strings.ReplaceAll(unit, "*", "_")
unit = strings.ReplaceAll(unit, "/", "_per_")
// name has - replaced with _ and is concatenated with the unit and
// other data.
name = strings.ReplaceAll(name, "-", "_")
name += "_" + unit
if d.Cumulative && d.Kind != metrics.KindFloat64Histogram {
name += "_total"
}
// Our current conversion moves to legacy naming, so use legacy validation.
valid := model.IsValidLegacyMetricName(namespace + "_" + subsystem + "_" + name)
switch d.Kind {
case metrics.KindUint64:
case metrics.KindFloat64:
case metrics.KindFloat64Histogram:
default:
valid = false
}
return namespace, subsystem, name, valid
}
// RuntimeMetricsBucketsForUnit takes a set of buckets obtained for a runtime/metrics histogram
// type (so, lower-bound inclusive) and a unit from a runtime/metrics name, and produces
// a reduced set of buckets. This function always removes any -Inf bucket as it's represented
// as the bottom-most upper-bound inclusive bucket in Prometheus.
func RuntimeMetricsBucketsForUnit(buckets []float64, unit string) []float64 {
switch unit {
case "bytes":
// Re-bucket as powers of 2.
return reBucketExp(buckets, 2)
case "seconds":
// Re-bucket as powers of 10 and then merge all buckets greater
// than 1 second into the +Inf bucket.
b := reBucketExp(buckets, 10)
for i := range b {
if b[i] <= 1 {
continue
}
b[i] = math.Inf(1)
b = b[:i+1]
break
}
return b
}
return buckets
}
// reBucketExp takes a list of bucket boundaries (lower bound inclusive) and
// downsamples the buckets to those a multiple of base apart. The end result
// is a roughly exponential (in many cases, perfectly exponential) bucketing
// scheme.
func reBucketExp(buckets []float64, base float64) []float64 {
bucket := buckets[0]
var newBuckets []float64
// We may see a -Inf here, in which case, add it and skip it
// since we risk producing NaNs otherwise.
//
// We need to preserve -Inf values to maintain runtime/metrics
// conventions. We'll strip it out later.
if bucket == math.Inf(-1) {
newBuckets = append(newBuckets, bucket)
buckets = buckets[1:]
bucket = buckets[0]
}
// From now on, bucket should always have a non-Inf value because
// Infs are only ever at the ends of the bucket lists, so
// arithmetic operations on it are non-NaN.
for i := 1; i < len(buckets); i++ {
if bucket >= 0 && buckets[i] < bucket*base {
// The next bucket we want to include is at least bucket*base.
continue
} else if bucket < 0 && buckets[i] < bucket/base {
// In this case the bucket we're targeting is negative, and since
// we're ascending through buckets here, we need to divide to get
// closer to zero exponentially.
continue
}
// The +Inf bucket will always be the last one, and we'll always
// end up including it here because bucket
newBuckets = append(newBuckets, bucket)
bucket = buckets[i]
}
return append(newBuckets, bucket)
}

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// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package internal
import (
"sort"
dto "github.com/prometheus/client_model/go"
)
// LabelPairSorter implements sort.Interface. It is used to sort a slice of
// dto.LabelPair pointers.
type LabelPairSorter []*dto.LabelPair
func (s LabelPairSorter) Len() int {
return len(s)
}
func (s LabelPairSorter) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s LabelPairSorter) Less(i, j int) bool {
return s[i].GetName() < s[j].GetName()
}
// MetricSorter is a sortable slice of *dto.Metric.
type MetricSorter []*dto.Metric
func (s MetricSorter) Len() int {
return len(s)
}
func (s MetricSorter) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s MetricSorter) Less(i, j int) bool {
if len(s[i].Label) != len(s[j].Label) {
// This should not happen. The metrics are
// inconsistent. However, we have to deal with the fact, as
// people might use custom collectors or metric family injection
// to create inconsistent metrics. So let's simply compare the
// number of labels in this case. That will still yield
// reproducible sorting.
return len(s[i].Label) < len(s[j].Label)
}
for n, lp := range s[i].Label {
vi := lp.GetValue()
vj := s[j].Label[n].GetValue()
if vi != vj {
return vi < vj
}
}
// We should never arrive here. Multiple metrics with the same
// label set in the same scrape will lead to undefined ingestion
// behavior. However, as above, we have to provide stable sorting
// here, even for inconsistent metrics. So sort equal metrics
// by their timestamp, with missing timestamps (implying "now")
// coming last.
if s[i].TimestampMs == nil {
return false
}
if s[j].TimestampMs == nil {
return true
}
return s[i].GetTimestampMs() < s[j].GetTimestampMs()
}
// NormalizeMetricFamilies returns a MetricFamily slice with empty
// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
// the slice, with the contained Metrics sorted within each MetricFamily.
func NormalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
for _, mf := range metricFamiliesByName {
sort.Sort(MetricSorter(mf.Metric))
}
names := make([]string, 0, len(metricFamiliesByName))
for name, mf := range metricFamiliesByName {
if len(mf.Metric) > 0 {
names = append(names, name)
}
}
sort.Strings(names)
result := make([]*dto.MetricFamily, 0, len(names))
for _, name := range names {
result = append(result, metricFamiliesByName[name])
}
return result
}

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// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"fmt"
"strings"
"unicode/utf8"
"github.com/prometheus/common/model"
)
// Labels represents a collection of label name -> value mappings. This type is
// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
// metric vector Collectors, e.g.:
//
// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
//
// The other use-case is the specification of constant label pairs in Opts or to
// create a Desc.
type Labels map[string]string
// LabelConstraint normalizes label values.
type LabelConstraint func(string) string
// ConstrainedLabels represents a label name and its constrain function
// to normalize label values. This type is commonly used when constructing
// metric vector Collectors.
type ConstrainedLabel struct {
Name string
Constraint LabelConstraint
}
// ConstrainableLabels is an interface that allows creating of labels that can
// be optionally constrained.
//
// prometheus.V2().NewCounterVec(CounterVecOpts{
// CounterOpts: {...}, // Usual CounterOpts fields
// VariableLabels: []ConstrainedLabels{
// {Name: "A"},
// {Name: "B", Constraint: func(v string) string { ... }},
// },
// })
type ConstrainableLabels interface {
compile() *compiledLabels
labelNames() []string
}
// ConstrainedLabels represents a collection of label name -> constrain function
// to normalize label values. This type is commonly used when constructing
// metric vector Collectors.
type ConstrainedLabels []ConstrainedLabel
func (cls ConstrainedLabels) compile() *compiledLabels {
compiled := &compiledLabels{
names: make([]string, len(cls)),
labelConstraints: map[string]LabelConstraint{},
}
for i, label := range cls {
compiled.names[i] = label.Name
if label.Constraint != nil {
compiled.labelConstraints[label.Name] = label.Constraint
}
}
return compiled
}
func (cls ConstrainedLabels) labelNames() []string {
names := make([]string, len(cls))
for i, label := range cls {
names[i] = label.Name
}
return names
}
// UnconstrainedLabels represents collection of label without any constraint on
// their value. Thus, it is simply a collection of label names.
//
// UnconstrainedLabels([]string{ "A", "B" })
//
// is equivalent to
//
// ConstrainedLabels {
// { Name: "A" },
// { Name: "B" },
// }
type UnconstrainedLabels []string
func (uls UnconstrainedLabels) compile() *compiledLabels {
return &compiledLabels{
names: uls,
}
}
func (uls UnconstrainedLabels) labelNames() []string {
return uls
}
type compiledLabels struct {
names []string
labelConstraints map[string]LabelConstraint
}
func (cls *compiledLabels) compile() *compiledLabels {
return cls
}
func (cls *compiledLabels) labelNames() []string {
return cls.names
}
func (cls *compiledLabels) constrain(labelName, value string) string {
if fn, ok := cls.labelConstraints[labelName]; ok && fn != nil {
return fn(value)
}
return value
}
// reservedLabelPrefix is a prefix which is not legal in user-supplied
// label names.
const reservedLabelPrefix = "__"
var errInconsistentCardinality = errors.New("inconsistent label cardinality")
func makeInconsistentCardinalityError(fqName string, labels, labelValues []string) error {
return fmt.Errorf(
"%w: %q has %d variable labels named %q but %d values %q were provided",
errInconsistentCardinality, fqName,
len(labels), labels,
len(labelValues), labelValues,
)
}
func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
if len(labels) != expectedNumberOfValues {
return fmt.Errorf(
"%w: expected %d label values but got %d in %#v",
errInconsistentCardinality, expectedNumberOfValues,
len(labels), labels,
)
}
for name, val := range labels {
if !utf8.ValidString(val) {
return fmt.Errorf("label %s: value %q is not valid UTF-8", name, val)
}
}
return nil
}
func validateLabelValues(vals []string, expectedNumberOfValues int) error {
if len(vals) != expectedNumberOfValues {
// The call below makes vals escape, copy them to avoid that.
vals := append([]string(nil), vals...)
return fmt.Errorf(
"%w: expected %d label values but got %d in %#v",
errInconsistentCardinality, expectedNumberOfValues,
len(vals), vals,
)
}
for _, val := range vals {
if !utf8.ValidString(val) {
return fmt.Errorf("label value %q is not valid UTF-8", val)
}
}
return nil
}
func checkLabelName(l string) bool {
return model.LabelName(l).IsValid() && !strings.HasPrefix(l, reservedLabelPrefix)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"math"
"sort"
"strings"
"time"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/common/model"
"google.golang.org/protobuf/proto"
)
var separatorByteSlice = []byte{model.SeparatorByte} // For convenient use with xxhash.
// A Metric models a single sample value with its meta data being exported to
// Prometheus. Implementations of Metric in this package are Gauge, Counter,
// Histogram, Summary, and Untyped.
type Metric interface {
// Desc returns the descriptor for the Metric. This method idempotently
// returns the same descriptor throughout the lifetime of the
// Metric. The returned descriptor is immutable by contract. A Metric
// unable to describe itself must return an invalid descriptor (created
// with NewInvalidDesc).
Desc() *Desc
// Write encodes the Metric into a "Metric" Protocol Buffer data
// transmission object.
//
// Metric implementations must observe concurrency safety as reads of
// this metric may occur at any time, and any blocking occurs at the
// expense of total performance of rendering all registered
// metrics. Ideally, Metric implementations should support concurrent
// readers.
//
// While populating dto.Metric, it is the responsibility of the
// implementation to ensure validity of the Metric protobuf (like valid
// UTF-8 strings or syntactically valid metric and label names). It is
// recommended to sort labels lexicographically. Callers of Write should
// still make sure of sorting if they depend on it.
Write(*dto.Metric) error
// TODO(beorn7): The original rationale of passing in a pre-allocated
// dto.Metric protobuf to save allocations has disappeared. The
// signature of this method should be changed to "Write() (*dto.Metric,
// error)".
}
// Opts bundles the options for creating most Metric types. Each metric
// implementation XXX has its own XXXOpts type, but in most cases, it is just
// an alias of this type (which might change when the requirement arises.)
//
// It is mandatory to set Name to a non-empty string. All other fields are
// optional and can safely be left at their zero value, although it is strongly
// encouraged to set a Help string.
type Opts struct {
// Namespace, Subsystem, and Name are components of the fully-qualified
// name of the Metric (created by joining these components with
// "_"). Only Name is mandatory, the others merely help structuring the
// name. Note that the fully-qualified name of the metric must be a
// valid Prometheus metric name.
Namespace string
Subsystem string
Name string
// Help provides information about this metric.
//
// Metrics with the same fully-qualified name must have the same Help
// string.
Help string
// ConstLabels are used to attach fixed labels to this metric. Metrics
// with the same fully-qualified name must have the same label names in
// their ConstLabels.
//
// ConstLabels are only used rarely. In particular, do not use them to
// attach the same labels to all your metrics. Those use cases are
// better covered by target labels set by the scraping Prometheus
// server, or by one specific metric (e.g. a build_info or a
// machine_role metric). See also
// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels-not-static-scraped-labels
ConstLabels Labels
// now is for testing purposes, by default it's time.Now.
now func() time.Time
}
// BuildFQName joins the given three name components by "_". Empty name
// components are ignored. If the name parameter itself is empty, an empty
// string is returned, no matter what. Metric implementations included in this
// library use this function internally to generate the fully-qualified metric
// name from the name component in their Opts. Users of the library will only
// need this function if they implement their own Metric or instantiate a Desc
// (with NewDesc) directly.
func BuildFQName(namespace, subsystem, name string) string {
if name == "" {
return ""
}
sb := strings.Builder{}
sb.Grow(len(namespace) + len(subsystem) + len(name) + 2)
if namespace != "" {
sb.WriteString(namespace)
sb.WriteString("_")
}
if subsystem != "" {
sb.WriteString(subsystem)
sb.WriteString("_")
}
sb.WriteString(name)
return sb.String()
}
type invalidMetric struct {
desc *Desc
err error
}
// NewInvalidMetric returns a metric whose Write method always returns the
// provided error. It is useful if a Collector finds itself unable to collect
// a metric and wishes to report an error to the registry.
func NewInvalidMetric(desc *Desc, err error) Metric {
return &invalidMetric{desc, err}
}
func (m *invalidMetric) Desc() *Desc { return m.desc }
func (m *invalidMetric) Write(*dto.Metric) error { return m.err }
type timestampedMetric struct {
Metric
t time.Time
}
func (m timestampedMetric) Write(pb *dto.Metric) error {
e := m.Metric.Write(pb)
pb.TimestampMs = proto.Int64(m.t.Unix()*1000 + int64(m.t.Nanosecond()/1000000))
return e
}
// NewMetricWithTimestamp returns a new Metric wrapping the provided Metric in a
// way that it has an explicit timestamp set to the provided Time. This is only
// useful in rare cases as the timestamp of a Prometheus metric should usually
// be set by the Prometheus server during scraping. Exceptions include mirroring
// metrics with given timestamps from other metric
// sources.
//
// NewMetricWithTimestamp works best with MustNewConstMetric,
// MustNewConstHistogram, and MustNewConstSummary, see example.
//
// Currently, the exposition formats used by Prometheus are limited to
// millisecond resolution. Thus, the provided time will be rounded down to the
// next full millisecond value.
func NewMetricWithTimestamp(t time.Time, m Metric) Metric {
return timestampedMetric{Metric: m, t: t}
}
type withExemplarsMetric struct {
Metric
exemplars []*dto.Exemplar
}
func (m *withExemplarsMetric) Write(pb *dto.Metric) error {
if err := m.Metric.Write(pb); err != nil {
return err
}
switch {
case pb.Counter != nil:
pb.Counter.Exemplar = m.exemplars[len(m.exemplars)-1]
case pb.Histogram != nil:
for _, e := range m.exemplars {
// pb.Histogram.Bucket are sorted by UpperBound.
i := sort.Search(len(pb.Histogram.Bucket), func(i int) bool {
return pb.Histogram.Bucket[i].GetUpperBound() >= e.GetValue()
})
if i < len(pb.Histogram.Bucket) {
pb.Histogram.Bucket[i].Exemplar = e
} else {
// The +Inf bucket should be explicitly added if there is an exemplar for it, similar to non-const histogram logic in https://github.com/prometheus/client_golang/blob/main/prometheus/histogram.go#L357-L365.
b := &dto.Bucket{
CumulativeCount: proto.Uint64(pb.Histogram.GetSampleCount()),
UpperBound: proto.Float64(math.Inf(1)),
Exemplar: e,
}
pb.Histogram.Bucket = append(pb.Histogram.Bucket, b)
}
}
default:
// TODO(bwplotka): Implement Gauge?
return errors.New("cannot inject exemplar into Gauge, Summary or Untyped")
}
return nil
}
// Exemplar is easier to use, user-facing representation of *dto.Exemplar.
type Exemplar struct {
Value float64
Labels Labels
// Optional.
// Default value (time.Time{}) indicates its empty, which should be
// understood as time.Now() time at the moment of creation of metric.
Timestamp time.Time
}
// NewMetricWithExemplars returns a new Metric wrapping the provided Metric with given
// exemplars. Exemplars are validated.
//
// Only last applicable exemplar is injected from the list.
// For example for Counter it means last exemplar is injected.
// For Histogram, it means last applicable exemplar for each bucket is injected.
//
// NewMetricWithExemplars works best with MustNewConstMetric and
// MustNewConstHistogram, see example.
func NewMetricWithExemplars(m Metric, exemplars ...Exemplar) (Metric, error) {
if len(exemplars) == 0 {
return nil, errors.New("no exemplar was passed for NewMetricWithExemplars")
}
var (
now = time.Now()
exs = make([]*dto.Exemplar, len(exemplars))
err error
)
for i, e := range exemplars {
ts := e.Timestamp
if ts.IsZero() {
ts = now
}
exs[i], err = newExemplar(e.Value, ts, e.Labels)
if err != nil {
return nil, err
}
}
return &withExemplarsMetric{Metric: m, exemplars: exs}, nil
}
// MustNewMetricWithExemplars is a version of NewMetricWithExemplars that panics where
// NewMetricWithExemplars would have returned an error.
func MustNewMetricWithExemplars(m Metric, exemplars ...Exemplar) Metric {
ret, err := NewMetricWithExemplars(m, exemplars...)
if err != nil {
panic(err)
}
return ret
}

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// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build !js || wasm
// +build !js wasm
package prometheus
import "runtime"
// getRuntimeNumThreads returns the number of open OS threads.
func getRuntimeNumThreads() float64 {
n, _ := runtime.ThreadCreateProfile(nil)
return float64(n)
}

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// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build js && !wasm
// +build js,!wasm
package prometheus
// getRuntimeNumThreads returns the number of open OS threads.
func getRuntimeNumThreads() float64 {
return 1
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// Observer is the interface that wraps the Observe method, which is used by
// Histogram and Summary to add observations.
type Observer interface {
Observe(float64)
}
// The ObserverFunc type is an adapter to allow the use of ordinary
// functions as Observers. If f is a function with the appropriate
// signature, ObserverFunc(f) is an Observer that calls f.
//
// This adapter is usually used in connection with the Timer type, and there are
// two general use cases:
//
// The most common one is to use a Gauge as the Observer for a Timer.
// See the "Gauge" Timer example.
//
// The more advanced use case is to create a function that dynamically decides
// which Observer to use for observing the duration. See the "Complex" Timer
// example.
type ObserverFunc func(float64)
// Observe calls f(value). It implements Observer.
func (f ObserverFunc) Observe(value float64) {
f(value)
}
// ObserverVec is an interface implemented by `HistogramVec` and `SummaryVec`.
type ObserverVec interface {
GetMetricWith(Labels) (Observer, error)
GetMetricWithLabelValues(lvs ...string) (Observer, error)
With(Labels) Observer
WithLabelValues(...string) Observer
CurryWith(Labels) (ObserverVec, error)
MustCurryWith(Labels) ObserverVec
Collector
}
// ExemplarObserver is implemented by Observers that offer the option of
// observing a value together with an exemplar. Its ObserveWithExemplar method
// works like the Observe method of an Observer but also replaces the currently
// saved exemplar (if any) with a new one, created from the provided value, the
// current time as timestamp, and the provided Labels. Empty Labels will lead to
// a valid (label-less) exemplar. But if Labels is nil, the current exemplar is
// left in place. ObserveWithExemplar panics if any of the provided labels are
// invalid or if the provided labels contain more than 128 runes in total.
type ExemplarObserver interface {
ObserveWithExemplar(value float64, exemplar Labels)
}

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// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"fmt"
"os"
"strconv"
"strings"
)
type processCollector struct {
collectFn func(chan<- Metric)
describeFn func(chan<- *Desc)
pidFn func() (int, error)
reportErrors bool
cpuTotal *Desc
openFDs, maxFDs *Desc
vsize, maxVsize *Desc
rss *Desc
startTime *Desc
inBytes, outBytes *Desc
}
// ProcessCollectorOpts defines the behavior of a process metrics collector
// created with NewProcessCollector.
type ProcessCollectorOpts struct {
// PidFn returns the PID of the process the collector collects metrics
// for. It is called upon each collection. By default, the PID of the
// current process is used, as determined on construction time by
// calling os.Getpid().
PidFn func() (int, error)
// If non-empty, each of the collected metrics is prefixed by the
// provided string and an underscore ("_").
Namespace string
// If true, any error encountered during collection is reported as an
// invalid metric (see NewInvalidMetric). Otherwise, errors are ignored
// and the collected metrics will be incomplete. (Possibly, no metrics
// will be collected at all.) While that's usually not desired, it is
// appropriate for the common "mix-in" of process metrics, where process
// metrics are nice to have, but failing to collect them should not
// disrupt the collection of the remaining metrics.
ReportErrors bool
}
// NewProcessCollector is the obsolete version of collectors.NewProcessCollector.
// See there for documentation.
//
// Deprecated: Use collectors.NewProcessCollector instead.
func NewProcessCollector(opts ProcessCollectorOpts) Collector {
ns := ""
if len(opts.Namespace) > 0 {
ns = opts.Namespace + "_"
}
c := &processCollector{
reportErrors: opts.ReportErrors,
cpuTotal: NewDesc(
ns+"process_cpu_seconds_total",
"Total user and system CPU time spent in seconds.",
nil, nil,
),
openFDs: NewDesc(
ns+"process_open_fds",
"Number of open file descriptors.",
nil, nil,
),
maxFDs: NewDesc(
ns+"process_max_fds",
"Maximum number of open file descriptors.",
nil, nil,
),
vsize: NewDesc(
ns+"process_virtual_memory_bytes",
"Virtual memory size in bytes.",
nil, nil,
),
maxVsize: NewDesc(
ns+"process_virtual_memory_max_bytes",
"Maximum amount of virtual memory available in bytes.",
nil, nil,
),
rss: NewDesc(
ns+"process_resident_memory_bytes",
"Resident memory size in bytes.",
nil, nil,
),
startTime: NewDesc(
ns+"process_start_time_seconds",
"Start time of the process since unix epoch in seconds.",
nil, nil,
),
inBytes: NewDesc(
ns+"process_network_receive_bytes_total",
"Number of bytes received by the process over the network.",
nil, nil,
),
outBytes: NewDesc(
ns+"process_network_transmit_bytes_total",
"Number of bytes sent by the process over the network.",
nil, nil,
),
}
if opts.PidFn == nil {
c.pidFn = getPIDFn()
} else {
c.pidFn = opts.PidFn
}
// Set up process metric collection if supported by the runtime.
if canCollectProcess() {
c.collectFn = c.processCollect
c.describeFn = c.describe
} else {
c.collectFn = c.errorCollectFn
c.describeFn = c.errorDescribeFn
}
return c
}
func (c *processCollector) errorCollectFn(ch chan<- Metric) {
c.reportError(ch, nil, errors.New("process metrics not supported on this platform"))
}
func (c *processCollector) errorDescribeFn(ch chan<- *Desc) {
if c.reportErrors {
ch <- NewInvalidDesc(errors.New("process metrics not supported on this platform"))
}
}
// Collect returns the current state of all metrics of the collector.
func (c *processCollector) Collect(ch chan<- Metric) {
c.collectFn(ch)
}
// Describe returns all descriptions of the collector.
func (c *processCollector) Describe(ch chan<- *Desc) {
c.describeFn(ch)
}
func (c *processCollector) reportError(ch chan<- Metric, desc *Desc, err error) {
if !c.reportErrors {
return
}
if desc == nil {
desc = NewInvalidDesc(err)
}
ch <- NewInvalidMetric(desc, err)
}
// NewPidFileFn returns a function that retrieves a pid from the specified file.
// It is meant to be used for the PidFn field in ProcessCollectorOpts.
func NewPidFileFn(pidFilePath string) func() (int, error) {
return func() (int, error) {
content, err := os.ReadFile(pidFilePath)
if err != nil {
return 0, fmt.Errorf("can't read pid file %q: %w", pidFilePath, err)
}
pid, err := strconv.Atoi(strings.TrimSpace(string(content)))
if err != nil {
return 0, fmt.Errorf("can't parse pid file %q: %w", pidFilePath, err)
}
return pid, nil
}
}

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// Copyright 2024 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build darwin && cgo
#include <mach/mach_init.h>
#include <mach/task.h>
#include <mach/mach_vm.h>
// The compiler warns that mach/shared_memory_server.h is deprecated, and to use
// mach/shared_region.h instead. But that doesn't define
// SHARED_DATA_REGION_SIZE or SHARED_TEXT_REGION_SIZE, so redefine them here and
// avoid a warning message when running tests.
#define GLOBAL_SHARED_TEXT_SEGMENT 0x90000000U
#define SHARED_DATA_REGION_SIZE 0x10000000
#define SHARED_TEXT_REGION_SIZE 0x10000000
int get_memory_info(unsigned long long *rss, unsigned long long *vsize)
{
// This is lightly adapted from how ps(1) obtains its memory info.
// https://github.com/apple-oss-distributions/adv_cmds/blob/8744084ea0ff41ca4bb96b0f9c22407d0e48e9b7/ps/tasks.c#L109
kern_return_t error;
task_t task = MACH_PORT_NULL;
mach_task_basic_info_data_t info;
mach_msg_type_number_t info_count = MACH_TASK_BASIC_INFO_COUNT;
error = task_info(
mach_task_self(),
MACH_TASK_BASIC_INFO,
(task_info_t) &info,
&info_count );
if( error != KERN_SUCCESS )
{
return error;
}
*rss = info.resident_size;
*vsize = info.virtual_size;
{
vm_region_basic_info_data_64_t b_info;
mach_vm_address_t address = GLOBAL_SHARED_TEXT_SEGMENT;
mach_vm_size_t size;
mach_port_t object_name;
/*
* try to determine if this task has the split libraries
* mapped in... if so, adjust its virtual size down by
* the 2 segments that are used for split libraries
*/
info_count = VM_REGION_BASIC_INFO_COUNT_64;
error = mach_vm_region(
mach_task_self(),
&address,
&size,
VM_REGION_BASIC_INFO_64,
(vm_region_info_t) &b_info,
&info_count,
&object_name);
if (error == KERN_SUCCESS) {
if (b_info.reserved && size == (SHARED_TEXT_REGION_SIZE) &&
*vsize > (SHARED_TEXT_REGION_SIZE + SHARED_DATA_REGION_SIZE)) {
*vsize -= (SHARED_TEXT_REGION_SIZE + SHARED_DATA_REGION_SIZE);
}
}
}
return 0;
}

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// Copyright 2024 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build darwin && cgo
package prometheus
/*
int get_memory_info(unsigned long long *rss, unsigned long long *vs);
*/
import "C"
import "fmt"
func getMemory() (*memoryInfo, error) {
var rss, vsize C.ulonglong
if err := C.get_memory_info(&rss, &vsize); err != 0 {
return nil, fmt.Errorf("task_info() failed with 0x%x", int(err))
}
return &memoryInfo{vsize: uint64(vsize), rss: uint64(rss)}, nil
}
// describe returns all descriptions of the collector for Darwin.
// Ensure that this list of descriptors is kept in sync with the metrics collected
// in the processCollect method. Any changes to the metrics in processCollect
// (such as adding or removing metrics) should be reflected in this list of descriptors.
func (c *processCollector) describe(ch chan<- *Desc) {
ch <- c.cpuTotal
ch <- c.openFDs
ch <- c.maxFDs
ch <- c.maxVsize
ch <- c.startTime
ch <- c.rss
ch <- c.vsize
/* the process could be collected but not implemented yet
ch <- c.inBytes
ch <- c.outBytes
*/
}

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// Copyright 2024 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"fmt"
"os"
"syscall"
"time"
"golang.org/x/sys/unix"
)
// notImplementedErr is returned by stub functions that replace cgo functions, when cgo
// isn't available.
var notImplementedErr = errors.New("not implemented")
type memoryInfo struct {
vsize uint64 // Virtual memory size in bytes
rss uint64 // Resident memory size in bytes
}
func canCollectProcess() bool {
return true
}
func getSoftLimit(which int) (uint64, error) {
rlimit := syscall.Rlimit{}
if err := syscall.Getrlimit(which, &rlimit); err != nil {
return 0, err
}
return rlimit.Cur, nil
}
func getOpenFileCount() (float64, error) {
// Alternately, the undocumented proc_pidinfo(PROC_PIDLISTFDS) can be used to
// return a list of open fds, but that requires a way to call C APIs. The
// benefits, however, include fewer system calls and not failing when at the
// open file soft limit.
if dir, err := os.Open("/dev/fd"); err != nil {
return 0.0, err
} else {
defer dir.Close()
// Avoid ReadDir(), as it calls stat(2) on each descriptor. Not only is
// that info not used, but KQUEUE descriptors fail stat(2), which causes
// the whole method to fail.
if names, err := dir.Readdirnames(0); err != nil {
return 0.0, err
} else {
// Subtract 1 to ignore the open /dev/fd descriptor above.
return float64(len(names) - 1), nil
}
}
}
func (c *processCollector) processCollect(ch chan<- Metric) {
if procs, err := unix.SysctlKinfoProcSlice("kern.proc.pid", os.Getpid()); err == nil {
if len(procs) == 1 {
startTime := float64(procs[0].Proc.P_starttime.Nano() / 1e9)
ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
} else {
err = fmt.Errorf("sysctl() returned %d proc structs (expected 1)", len(procs))
c.reportError(ch, c.startTime, err)
}
} else {
c.reportError(ch, c.startTime, err)
}
// The proc structure returned by kern.proc.pid above has an Rusage member,
// but it is not filled in, so it needs to be fetched by getrusage(2). For
// that call, the UTime, STime, and Maxrss members are filled out, but not
// Ixrss, Idrss, or Isrss for the memory usage. Memory stats will require
// access to the C API to call task_info(TASK_BASIC_INFO).
rusage := unix.Rusage{}
if err := unix.Getrusage(syscall.RUSAGE_SELF, &rusage); err == nil {
cpuTime := time.Duration(rusage.Stime.Nano() + rusage.Utime.Nano()).Seconds()
ch <- MustNewConstMetric(c.cpuTotal, CounterValue, cpuTime)
} else {
c.reportError(ch, c.cpuTotal, err)
}
if memInfo, err := getMemory(); err == nil {
ch <- MustNewConstMetric(c.rss, GaugeValue, float64(memInfo.rss))
ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(memInfo.vsize))
} else if !errors.Is(err, notImplementedErr) {
// Don't report an error when support is not compiled in.
c.reportError(ch, c.rss, err)
c.reportError(ch, c.vsize, err)
}
if fds, err := getOpenFileCount(); err == nil {
ch <- MustNewConstMetric(c.openFDs, GaugeValue, fds)
} else {
c.reportError(ch, c.openFDs, err)
}
if openFiles, err := getSoftLimit(syscall.RLIMIT_NOFILE); err == nil {
ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(openFiles))
} else {
c.reportError(ch, c.maxFDs, err)
}
if addressSpace, err := getSoftLimit(syscall.RLIMIT_AS); err == nil {
ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(addressSpace))
} else {
c.reportError(ch, c.maxVsize, err)
}
// TODO: socket(PF_SYSTEM) to fetch "com.apple.network.statistics" might
// be able to get the per-process network send/receive counts.
}

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// Copyright 2024 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build darwin && !cgo
package prometheus
func getMemory() (*memoryInfo, error) {
return nil, notImplementedErr
}
// describe returns all descriptions of the collector for Darwin.
// Ensure that this list of descriptors is kept in sync with the metrics collected
// in the processCollect method. Any changes to the metrics in processCollect
// (such as adding or removing metrics) should be reflected in this list of descriptors.
func (c *processCollector) describe(ch chan<- *Desc) {
ch <- c.cpuTotal
ch <- c.openFDs
ch <- c.maxFDs
ch <- c.maxVsize
ch <- c.startTime
/* the process could be collected but not implemented yet
ch <- c.rss
ch <- c.vsize
ch <- c.inBytes
ch <- c.outBytes
*/
}

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// Copyright 2019 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build !windows && !js && !wasip1 && !darwin
// +build !windows,!js,!wasip1,!darwin
package prometheus
import (
"github.com/prometheus/procfs"
)
func canCollectProcess() bool {
_, err := procfs.NewDefaultFS()
return err == nil
}
func (c *processCollector) processCollect(ch chan<- Metric) {
pid, err := c.pidFn()
if err != nil {
c.reportError(ch, nil, err)
return
}
p, err := procfs.NewProc(pid)
if err != nil {
c.reportError(ch, nil, err)
return
}
if stat, err := p.Stat(); err == nil {
ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
if startTime, err := stat.StartTime(); err == nil {
ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
} else {
c.reportError(ch, c.startTime, err)
}
} else {
c.reportError(ch, nil, err)
}
if fds, err := p.FileDescriptorsLen(); err == nil {
ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
} else {
c.reportError(ch, c.openFDs, err)
}
if limits, err := p.Limits(); err == nil {
ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace))
} else {
c.reportError(ch, nil, err)
}
if netstat, err := p.Netstat(); err == nil {
var inOctets, outOctets float64
if netstat.IpExt.InOctets != nil {
inOctets = *netstat.IpExt.InOctets
}
if netstat.IpExt.OutOctets != nil {
outOctets = *netstat.IpExt.OutOctets
}
ch <- MustNewConstMetric(c.inBytes, CounterValue, inOctets)
ch <- MustNewConstMetric(c.outBytes, CounterValue, outOctets)
} else {
c.reportError(ch, nil, err)
}
}
// describe returns all descriptions of the collector for others than windows, js, wasip1 and darwin.
// Ensure that this list of descriptors is kept in sync with the metrics collected
// in the processCollect method. Any changes to the metrics in processCollect
// (such as adding or removing metrics) should be reflected in this list of descriptors.
func (c *processCollector) describe(ch chan<- *Desc) {
ch <- c.cpuTotal
ch <- c.openFDs
ch <- c.maxFDs
ch <- c.vsize
ch <- c.maxVsize
ch <- c.rss
ch <- c.startTime
ch <- c.inBytes
ch <- c.outBytes
}

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// Copyright 2023 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//go:build wasip1 || js
// +build wasip1 js
package prometheus
func canCollectProcess() bool {
return false
}
func (c *processCollector) processCollect(ch chan<- Metric) {
c.errorCollectFn(ch)
}
// describe returns all descriptions of the collector for wasip1 and js.
// Ensure that this list of descriptors is kept in sync with the metrics collected
// in the processCollect method. Any changes to the metrics in processCollect
// (such as adding or removing metrics) should be reflected in this list of descriptors.
func (c *processCollector) describe(ch chan<- *Desc) {
c.errorDescribeFn(ch)
}

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// Copyright 2019 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"syscall"
"unsafe"
"golang.org/x/sys/windows"
)
func canCollectProcess() bool {
return true
}
var (
modpsapi = syscall.NewLazyDLL("psapi.dll")
modkernel32 = syscall.NewLazyDLL("kernel32.dll")
procGetProcessMemoryInfo = modpsapi.NewProc("GetProcessMemoryInfo")
procGetProcessHandleCount = modkernel32.NewProc("GetProcessHandleCount")
)
type processMemoryCounters struct {
// System interface description
// https://docs.microsoft.com/en-us/windows/desktop/api/psapi/ns-psapi-process_memory_counters_ex
// Refer to the Golang internal implementation
// https://golang.org/src/internal/syscall/windows/psapi_windows.go
_ uint32
PageFaultCount uint32
PeakWorkingSetSize uintptr
WorkingSetSize uintptr
QuotaPeakPagedPoolUsage uintptr
QuotaPagedPoolUsage uintptr
QuotaPeakNonPagedPoolUsage uintptr
QuotaNonPagedPoolUsage uintptr
PagefileUsage uintptr
PeakPagefileUsage uintptr
PrivateUsage uintptr
}
func getProcessMemoryInfo(handle windows.Handle) (processMemoryCounters, error) {
mem := processMemoryCounters{}
r1, _, err := procGetProcessMemoryInfo.Call(
uintptr(handle),
uintptr(unsafe.Pointer(&mem)),
uintptr(unsafe.Sizeof(mem)),
)
if r1 != 1 {
return mem, err
} else {
return mem, nil
}
}
func getProcessHandleCount(handle windows.Handle) (uint32, error) {
var count uint32
r1, _, err := procGetProcessHandleCount.Call(
uintptr(handle),
uintptr(unsafe.Pointer(&count)),
)
if r1 != 1 {
return 0, err
} else {
return count, nil
}
}
func (c *processCollector) processCollect(ch chan<- Metric) {
h := windows.CurrentProcess()
var startTime, exitTime, kernelTime, userTime windows.Filetime
err := windows.GetProcessTimes(h, &startTime, &exitTime, &kernelTime, &userTime)
if err != nil {
c.reportError(ch, nil, err)
return
}
ch <- MustNewConstMetric(c.startTime, GaugeValue, float64(startTime.Nanoseconds()/1e9))
ch <- MustNewConstMetric(c.cpuTotal, CounterValue, fileTimeToSeconds(kernelTime)+fileTimeToSeconds(userTime))
mem, err := getProcessMemoryInfo(h)
if err != nil {
c.reportError(ch, nil, err)
return
}
ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(mem.PrivateUsage))
ch <- MustNewConstMetric(c.rss, GaugeValue, float64(mem.WorkingSetSize))
handles, err := getProcessHandleCount(h)
if err != nil {
c.reportError(ch, nil, err)
return
}
ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(handles))
ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(16*1024*1024)) // Windows has a hard-coded max limit, not per-process.
}
// describe returns all descriptions of the collector for windows.
// Ensure that this list of descriptors is kept in sync with the metrics collected
// in the processCollect method. Any changes to the metrics in processCollect
// (such as adding or removing metrics) should be reflected in this list of descriptors.
func (c *processCollector) describe(ch chan<- *Desc) {
ch <- c.cpuTotal
ch <- c.openFDs
ch <- c.maxFDs
ch <- c.vsize
ch <- c.rss
ch <- c.startTime
}
func fileTimeToSeconds(ft windows.Filetime) float64 {
return float64(uint64(ft.HighDateTime)<<32+uint64(ft.LowDateTime)) / 1e7
}

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// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"bufio"
"io"
"net"
"net/http"
)
const (
closeNotifier = 1 << iota
flusher
hijacker
readerFrom
pusher
)
type delegator interface {
http.ResponseWriter
Status() int
Written() int64
}
type responseWriterDelegator struct {
http.ResponseWriter
status int
written int64
wroteHeader bool
observeWriteHeader func(int)
}
func (r *responseWriterDelegator) Status() int {
return r.status
}
func (r *responseWriterDelegator) Written() int64 {
return r.written
}
func (r *responseWriterDelegator) WriteHeader(code int) {
if r.observeWriteHeader != nil && !r.wroteHeader {
// Only call observeWriteHeader for the 1st time. It's a bug if
// WriteHeader is called more than once, but we want to protect
// against it here. Note that we still delegate the WriteHeader
// to the original ResponseWriter to not mask the bug from it.
r.observeWriteHeader(code)
}
r.status = code
r.wroteHeader = true
r.ResponseWriter.WriteHeader(code)
}
func (r *responseWriterDelegator) Write(b []byte) (int, error) {
// If applicable, call WriteHeader here so that observeWriteHeader is
// handled appropriately.
if !r.wroteHeader {
r.WriteHeader(http.StatusOK)
}
n, err := r.ResponseWriter.Write(b)
r.written += int64(n)
return n, err
}
// Unwrap lets http.ResponseController get the underlying http.ResponseWriter,
// by implementing the [rwUnwrapper](https://cs.opensource.google/go/go/+/refs/tags/go1.21.4:src/net/http/responsecontroller.go;l=42-44) interface.
func (r *responseWriterDelegator) Unwrap() http.ResponseWriter {
return r.ResponseWriter
}
type (
closeNotifierDelegator struct{ *responseWriterDelegator }
flusherDelegator struct{ *responseWriterDelegator }
hijackerDelegator struct{ *responseWriterDelegator }
readerFromDelegator struct{ *responseWriterDelegator }
pusherDelegator struct{ *responseWriterDelegator }
)
func (d closeNotifierDelegator) CloseNotify() <-chan bool {
//nolint:staticcheck // Ignore SA1019. http.CloseNotifier is deprecated but we keep it here to not break existing users.
return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
}
func (d flusherDelegator) Flush() {
// If applicable, call WriteHeader here so that observeWriteHeader is
// handled appropriately.
if !d.wroteHeader {
d.WriteHeader(http.StatusOK)
}
d.ResponseWriter.(http.Flusher).Flush()
}
func (d hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
return d.ResponseWriter.(http.Hijacker).Hijack()
}
func (d readerFromDelegator) ReadFrom(re io.Reader) (int64, error) {
// If applicable, call WriteHeader here so that observeWriteHeader is
// handled appropriately.
if !d.wroteHeader {
d.WriteHeader(http.StatusOK)
}
n, err := d.ResponseWriter.(io.ReaderFrom).ReadFrom(re)
d.written += n
return n, err
}
func (d pusherDelegator) Push(target string, opts *http.PushOptions) error {
return d.ResponseWriter.(http.Pusher).Push(target, opts)
}
var pickDelegator = make([]func(*responseWriterDelegator) delegator, 32)
func init() {
// TODO(beorn7): Code generation would help here.
pickDelegator[0] = func(d *responseWriterDelegator) delegator { // 0
return d
}
pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1
return closeNotifierDelegator{d}
}
pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2
return flusherDelegator{d}
}
pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3
return struct {
*responseWriterDelegator
http.Flusher
http.CloseNotifier
}{d, flusherDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4
return hijackerDelegator{d}
}
pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5
return struct {
*responseWriterDelegator
http.Hijacker
http.CloseNotifier
}{d, hijackerDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 6
return struct {
*responseWriterDelegator
http.Hijacker
http.Flusher
}{d, hijackerDelegator{d}, flusherDelegator{d}}
}
pickDelegator[hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 7
return struct {
*responseWriterDelegator
http.Hijacker
http.Flusher
http.CloseNotifier
}{d, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[readerFrom] = func(d *responseWriterDelegator) delegator { // 8
return readerFromDelegator{d}
}
pickDelegator[readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 9
return struct {
*responseWriterDelegator
io.ReaderFrom
http.CloseNotifier
}{d, readerFromDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 10
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Flusher
}{d, readerFromDelegator{d}, flusherDelegator{d}}
}
pickDelegator[readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 11
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Flusher
http.CloseNotifier
}{d, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 12
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Hijacker
}{d, readerFromDelegator{d}, hijackerDelegator{d}}
}
pickDelegator[readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 13
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Hijacker
http.CloseNotifier
}{d, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 14
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Hijacker
http.Flusher
}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
}
pickDelegator[readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 15
return struct {
*responseWriterDelegator
io.ReaderFrom
http.Hijacker
http.Flusher
http.CloseNotifier
}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16
return pusherDelegator{d}
}
pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17
return struct {
*responseWriterDelegator
http.Pusher
http.CloseNotifier
}{d, pusherDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[pusher+flusher] = func(d *responseWriterDelegator) delegator { // 18
return struct {
*responseWriterDelegator
http.Pusher
http.Flusher
}{d, pusherDelegator{d}, flusherDelegator{d}}
}
pickDelegator[pusher+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 19
return struct {
*responseWriterDelegator
http.Pusher
http.Flusher
http.CloseNotifier
}{d, pusherDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[pusher+hijacker] = func(d *responseWriterDelegator) delegator { // 20
return struct {
*responseWriterDelegator
http.Pusher
http.Hijacker
}{d, pusherDelegator{d}, hijackerDelegator{d}}
}
pickDelegator[pusher+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 21
return struct {
*responseWriterDelegator
http.Pusher
http.Hijacker
http.CloseNotifier
}{d, pusherDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[pusher+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 22
return struct {
*responseWriterDelegator
http.Pusher
http.Hijacker
http.Flusher
}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
}
pickDelegator[pusher+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 23
return struct {
*responseWriterDelegator
http.Pusher
http.Hijacker
http.Flusher
http.CloseNotifier
}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[pusher+readerFrom] = func(d *responseWriterDelegator) delegator { // 24
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
}{d, pusherDelegator{d}, readerFromDelegator{d}}
}
pickDelegator[pusher+readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 25
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.CloseNotifier
}{d, pusherDelegator{d}, readerFromDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[pusher+readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 26
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Flusher
}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}}
}
pickDelegator[pusher+readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 27
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Flusher
http.CloseNotifier
}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[pusher+readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 28
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Hijacker
}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}}
}
pickDelegator[pusher+readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 29
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Hijacker
http.CloseNotifier
}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
}
pickDelegator[pusher+readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 30
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Hijacker
http.Flusher
}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
}
pickDelegator[pusher+readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 31
return struct {
*responseWriterDelegator
http.Pusher
io.ReaderFrom
http.Hijacker
http.Flusher
http.CloseNotifier
}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
}
}
func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
d := &responseWriterDelegator{
ResponseWriter: w,
observeWriteHeader: observeWriteHeaderFunc,
}
id := 0
//nolint:staticcheck // Ignore SA1019. http.CloseNotifier is deprecated but we keep it here to not break existing users.
if _, ok := w.(http.CloseNotifier); ok {
id += closeNotifier
}
if _, ok := w.(http.Flusher); ok {
id += flusher
}
if _, ok := w.(http.Hijacker); ok {
id += hijacker
}
if _, ok := w.(io.ReaderFrom); ok {
id += readerFrom
}
if _, ok := w.(http.Pusher); ok {
id += pusher
}
return pickDelegator[id](d)
}

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@ -0,0 +1,488 @@
// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package promhttp provides tooling around HTTP servers and clients.
//
// First, the package allows the creation of http.Handler instances to expose
// Prometheus metrics via HTTP. promhttp.Handler acts on the
// prometheus.DefaultGatherer. With HandlerFor, you can create a handler for a
// custom registry or anything that implements the Gatherer interface. It also
// allows the creation of handlers that act differently on errors or allow to
// log errors.
//
// Second, the package provides tooling to instrument instances of http.Handler
// via middleware. Middleware wrappers follow the naming scheme
// InstrumentHandlerX, where X describes the intended use of the middleware.
// See each function's doc comment for specific details.
//
// Finally, the package allows for an http.RoundTripper to be instrumented via
// middleware. Middleware wrappers follow the naming scheme
// InstrumentRoundTripperX, where X describes the intended use of the
// middleware. See each function's doc comment for specific details.
package promhttp
import (
"compress/gzip"
"errors"
"fmt"
"io"
"net/http"
"strconv"
"sync"
"time"
"github.com/klauspost/compress/zstd"
"github.com/prometheus/common/expfmt"
"github.com/prometheus/client_golang/internal/github.com/golang/gddo/httputil"
"github.com/prometheus/client_golang/prometheus"
)
const (
contentTypeHeader = "Content-Type"
contentEncodingHeader = "Content-Encoding"
acceptEncodingHeader = "Accept-Encoding"
processStartTimeHeader = "Process-Start-Time-Unix"
)
// Compression represents the content encodings handlers support for the HTTP
// responses.
type Compression string
const (
Identity Compression = "identity"
Gzip Compression = "gzip"
Zstd Compression = "zstd"
)
var defaultCompressionFormats = []Compression{Identity, Gzip, Zstd}
var gzipPool = sync.Pool{
New: func() interface{} {
return gzip.NewWriter(nil)
},
}
// Handler returns an http.Handler for the prometheus.DefaultGatherer, using
// default HandlerOpts, i.e. it reports the first error as an HTTP error, it has
// no error logging, and it applies compression if requested by the client.
//
// The returned http.Handler is already instrumented using the
// InstrumentMetricHandler function and the prometheus.DefaultRegisterer. If you
// create multiple http.Handlers by separate calls of the Handler function, the
// metrics used for instrumentation will be shared between them, providing
// global scrape counts.
//
// This function is meant to cover the bulk of basic use cases. If you are doing
// anything that requires more customization (including using a non-default
// Gatherer, different instrumentation, and non-default HandlerOpts), use the
// HandlerFor function. See there for details.
func Handler() http.Handler {
return InstrumentMetricHandler(
prometheus.DefaultRegisterer, HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}),
)
}
// HandlerFor returns an uninstrumented http.Handler for the provided
// Gatherer. The behavior of the Handler is defined by the provided
// HandlerOpts. Thus, HandlerFor is useful to create http.Handlers for custom
// Gatherers, with non-default HandlerOpts, and/or with custom (or no)
// instrumentation. Use the InstrumentMetricHandler function to apply the same
// kind of instrumentation as it is used by the Handler function.
func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
return HandlerForTransactional(prometheus.ToTransactionalGatherer(reg), opts)
}
// HandlerForTransactional is like HandlerFor, but it uses transactional gather, which
// can safely change in-place returned *dto.MetricFamily before call to `Gather` and after
// call to `done` of that `Gather`.
func HandlerForTransactional(reg prometheus.TransactionalGatherer, opts HandlerOpts) http.Handler {
var (
inFlightSem chan struct{}
errCnt = prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "promhttp_metric_handler_errors_total",
Help: "Total number of internal errors encountered by the promhttp metric handler.",
},
[]string{"cause"},
)
)
if opts.MaxRequestsInFlight > 0 {
inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight)
}
if opts.Registry != nil {
// Initialize all possibilities that can occur below.
errCnt.WithLabelValues("gathering")
errCnt.WithLabelValues("encoding")
if err := opts.Registry.Register(errCnt); err != nil {
are := &prometheus.AlreadyRegisteredError{}
if errors.As(err, are) {
errCnt = are.ExistingCollector.(*prometheus.CounterVec)
} else {
panic(err)
}
}
}
// Select compression formats to offer based on default or user choice.
var compressions []string
if !opts.DisableCompression {
offers := defaultCompressionFormats
if len(opts.OfferedCompressions) > 0 {
offers = opts.OfferedCompressions
}
for _, comp := range offers {
compressions = append(compressions, string(comp))
}
}
h := http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
if !opts.ProcessStartTime.IsZero() {
rsp.Header().Set(processStartTimeHeader, strconv.FormatInt(opts.ProcessStartTime.Unix(), 10))
}
if inFlightSem != nil {
select {
case inFlightSem <- struct{}{}: // All good, carry on.
defer func() { <-inFlightSem }()
default:
http.Error(rsp, fmt.Sprintf(
"Limit of concurrent requests reached (%d), try again later.", opts.MaxRequestsInFlight,
), http.StatusServiceUnavailable)
return
}
}
mfs, done, err := reg.Gather()
defer done()
if err != nil {
if opts.ErrorLog != nil {
opts.ErrorLog.Println("error gathering metrics:", err)
}
errCnt.WithLabelValues("gathering").Inc()
switch opts.ErrorHandling {
case PanicOnError:
panic(err)
case ContinueOnError:
if len(mfs) == 0 {
// Still report the error if no metrics have been gathered.
httpError(rsp, err)
return
}
case HTTPErrorOnError:
httpError(rsp, err)
return
}
}
var contentType expfmt.Format
if opts.EnableOpenMetrics {
contentType = expfmt.NegotiateIncludingOpenMetrics(req.Header)
} else {
contentType = expfmt.Negotiate(req.Header)
}
rsp.Header().Set(contentTypeHeader, string(contentType))
w, encodingHeader, closeWriter, err := negotiateEncodingWriter(req, rsp, compressions)
if err != nil {
if opts.ErrorLog != nil {
opts.ErrorLog.Println("error getting writer", err)
}
w = io.Writer(rsp)
encodingHeader = string(Identity)
}
defer closeWriter()
// Set Content-Encoding only when data is compressed
if encodingHeader != string(Identity) {
rsp.Header().Set(contentEncodingHeader, encodingHeader)
}
var enc expfmt.Encoder
if opts.EnableOpenMetricsTextCreatedSamples {
enc = expfmt.NewEncoder(w, contentType, expfmt.WithCreatedLines())
} else {
enc = expfmt.NewEncoder(w, contentType)
}
// handleError handles the error according to opts.ErrorHandling
// and returns true if we have to abort after the handling.
handleError := func(err error) bool {
if err == nil {
return false
}
if opts.ErrorLog != nil {
opts.ErrorLog.Println("error encoding and sending metric family:", err)
}
errCnt.WithLabelValues("encoding").Inc()
switch opts.ErrorHandling {
case PanicOnError:
panic(err)
case HTTPErrorOnError:
// We cannot really send an HTTP error at this
// point because we most likely have written
// something to rsp already. But at least we can
// stop sending.
return true
}
// Do nothing in all other cases, including ContinueOnError.
return false
}
for _, mf := range mfs {
if handleError(enc.Encode(mf)) {
return
}
}
if closer, ok := enc.(expfmt.Closer); ok {
// This in particular takes care of the final "# EOF\n" line for OpenMetrics.
if handleError(closer.Close()) {
return
}
}
})
if opts.Timeout <= 0 {
return h
}
return http.TimeoutHandler(h, opts.Timeout, fmt.Sprintf(
"Exceeded configured timeout of %v.\n",
opts.Timeout,
))
}
// InstrumentMetricHandler is usually used with an http.Handler returned by the
// HandlerFor function. It instruments the provided http.Handler with two
// metrics: A counter vector "promhttp_metric_handler_requests_total" to count
// scrapes partitioned by HTTP status code, and a gauge
// "promhttp_metric_handler_requests_in_flight" to track the number of
// simultaneous scrapes. This function idempotently registers collectors for
// both metrics with the provided Registerer. It panics if the registration
// fails. The provided metrics are useful to see how many scrapes hit the
// monitored target (which could be from different Prometheus servers or other
// scrapers), and how often they overlap (which would result in more than one
// scrape in flight at the same time). Note that the scrapes-in-flight gauge
// will contain the scrape by which it is exposed, while the scrape counter will
// only get incremented after the scrape is complete (as only then the status
// code is known). For tracking scrape durations, use the
// "scrape_duration_seconds" gauge created by the Prometheus server upon each
// scrape.
func InstrumentMetricHandler(reg prometheus.Registerer, handler http.Handler) http.Handler {
cnt := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "promhttp_metric_handler_requests_total",
Help: "Total number of scrapes by HTTP status code.",
},
[]string{"code"},
)
// Initialize the most likely HTTP status codes.
cnt.WithLabelValues("200")
cnt.WithLabelValues("500")
cnt.WithLabelValues("503")
if err := reg.Register(cnt); err != nil {
are := &prometheus.AlreadyRegisteredError{}
if errors.As(err, are) {
cnt = are.ExistingCollector.(*prometheus.CounterVec)
} else {
panic(err)
}
}
gge := prometheus.NewGauge(prometheus.GaugeOpts{
Name: "promhttp_metric_handler_requests_in_flight",
Help: "Current number of scrapes being served.",
})
if err := reg.Register(gge); err != nil {
are := &prometheus.AlreadyRegisteredError{}
if errors.As(err, are) {
gge = are.ExistingCollector.(prometheus.Gauge)
} else {
panic(err)
}
}
return InstrumentHandlerCounter(cnt, InstrumentHandlerInFlight(gge, handler))
}
// HandlerErrorHandling defines how a Handler serving metrics will handle
// errors.
type HandlerErrorHandling int
// These constants cause handlers serving metrics to behave as described if
// errors are encountered.
const (
// Serve an HTTP status code 500 upon the first error
// encountered. Report the error message in the body. Note that HTTP
// errors cannot be served anymore once the beginning of a regular
// payload has been sent. Thus, in the (unlikely) case that encoding the
// payload into the negotiated wire format fails, serving the response
// will simply be aborted. Set an ErrorLog in HandlerOpts to detect
// those errors.
HTTPErrorOnError HandlerErrorHandling = iota
// Ignore errors and try to serve as many metrics as possible. However,
// if no metrics can be served, serve an HTTP status code 500 and the
// last error message in the body. Only use this in deliberate "best
// effort" metrics collection scenarios. In this case, it is highly
// recommended to provide other means of detecting errors: By setting an
// ErrorLog in HandlerOpts, the errors are logged. By providing a
// Registry in HandlerOpts, the exposed metrics include an error counter
// "promhttp_metric_handler_errors_total", which can be used for
// alerts.
ContinueOnError
// Panic upon the first error encountered (useful for "crash only" apps).
PanicOnError
)
// Logger is the minimal interface HandlerOpts needs for logging. Note that
// log.Logger from the standard library implements this interface, and it is
// easy to implement by custom loggers, if they don't do so already anyway.
type Logger interface {
Println(v ...interface{})
}
// HandlerOpts specifies options how to serve metrics via an http.Handler. The
// zero value of HandlerOpts is a reasonable default.
type HandlerOpts struct {
// ErrorLog specifies an optional Logger for errors collecting and
// serving metrics. If nil, errors are not logged at all. Note that the
// type of a reported error is often prometheus.MultiError, which
// formats into a multi-line error string. If you want to avoid the
// latter, create a Logger implementation that detects a
// prometheus.MultiError and formats the contained errors into one line.
ErrorLog Logger
// ErrorHandling defines how errors are handled. Note that errors are
// logged regardless of the configured ErrorHandling provided ErrorLog
// is not nil.
ErrorHandling HandlerErrorHandling
// If Registry is not nil, it is used to register a metric
// "promhttp_metric_handler_errors_total", partitioned by "cause". A
// failed registration causes a panic. Note that this error counter is
// different from the instrumentation you get from the various
// InstrumentHandler... helpers. It counts errors that don't necessarily
// result in a non-2xx HTTP status code. There are two typical cases:
// (1) Encoding errors that only happen after streaming of the HTTP body
// has already started (and the status code 200 has been sent). This
// should only happen with custom collectors. (2) Collection errors with
// no effect on the HTTP status code because ErrorHandling is set to
// ContinueOnError.
Registry prometheus.Registerer
// DisableCompression disables the response encoding (compression) and
// encoding negotiation. If true, the handler will
// never compress the response, even if requested
// by the client and the OfferedCompressions field is set.
DisableCompression bool
// OfferedCompressions is a set of encodings (compressions) handler will
// try to offer when negotiating with the client. This defaults to identity, gzip
// and zstd.
// NOTE: If handler can't agree with the client on the encodings or
// unsupported or empty encodings are set in OfferedCompressions,
// handler always fallbacks to no compression (identity), for
// compatibility reasons. In such cases ErrorLog will be used if set.
OfferedCompressions []Compression
// The number of concurrent HTTP requests is limited to
// MaxRequestsInFlight. Additional requests are responded to with 503
// Service Unavailable and a suitable message in the body. If
// MaxRequestsInFlight is 0 or negative, no limit is applied.
MaxRequestsInFlight int
// If handling a request takes longer than Timeout, it is responded to
// with 503 ServiceUnavailable and a suitable Message. No timeout is
// applied if Timeout is 0 or negative. Note that with the current
// implementation, reaching the timeout simply ends the HTTP requests as
// described above (and even that only if sending of the body hasn't
// started yet), while the bulk work of gathering all the metrics keeps
// running in the background (with the eventual result to be thrown
// away). Until the implementation is improved, it is recommended to
// implement a separate timeout in potentially slow Collectors.
Timeout time.Duration
// If true, the experimental OpenMetrics encoding is added to the
// possible options during content negotiation. Note that Prometheus
// 2.5.0+ will negotiate OpenMetrics as first priority. OpenMetrics is
// the only way to transmit exemplars. However, the move to OpenMetrics
// is not completely transparent. Most notably, the values of "quantile"
// labels of Summaries and "le" labels of Histograms are formatted with
// a trailing ".0" if they would otherwise look like integer numbers
// (which changes the identity of the resulting series on the Prometheus
// server).
EnableOpenMetrics bool
// EnableOpenMetricsTextCreatedSamples specifies if this handler should add, extra, synthetic
// Created Timestamps for counters, histograms and summaries, which for the current
// version of OpenMetrics are defined as extra series with the same name and "_created"
// suffix. See also the OpenMetrics specification for more details
// https://github.com/prometheus/OpenMetrics/blob/v1.0.0/specification/OpenMetrics.md#counter-1
//
// Created timestamps are used to improve the accuracy of reset detection,
// but the way it's designed in OpenMetrics 1.0 it also dramatically increases cardinality
// if the scraper does not handle those metrics correctly (converting to created timestamp
// instead of leaving those series as-is). New OpenMetrics versions might improve
// this situation.
//
// Prometheus introduced the feature flag 'created-timestamp-zero-ingestion'
// in version 2.50.0 to handle this situation.
EnableOpenMetricsTextCreatedSamples bool
// ProcessStartTime allows setting process start timevalue that will be exposed
// with "Process-Start-Time-Unix" response header along with the metrics
// payload. This allow callers to have efficient transformations to cumulative
// counters (e.g. OpenTelemetry) or generally _created timestamp estimation per
// scrape target.
// NOTE: This feature is experimental and not covered by OpenMetrics or Prometheus
// exposition format.
ProcessStartTime time.Time
}
// httpError removes any content-encoding header and then calls http.Error with
// the provided error and http.StatusInternalServerError. Error contents is
// supposed to be uncompressed plain text. Same as with a plain http.Error, this
// must not be called if the header or any payload has already been sent.
func httpError(rsp http.ResponseWriter, err error) {
rsp.Header().Del(contentEncodingHeader)
http.Error(
rsp,
"An error has occurred while serving metrics:\n\n"+err.Error(),
http.StatusInternalServerError,
)
}
// negotiateEncodingWriter reads the Accept-Encoding header from a request and
// selects the right compression based on an allow-list of supported
// compressions. It returns a writer implementing the compression and an the
// correct value that the caller can set in the response header.
func negotiateEncodingWriter(r *http.Request, rw io.Writer, compressions []string) (_ io.Writer, encodingHeaderValue string, closeWriter func(), _ error) {
if len(compressions) == 0 {
return rw, string(Identity), func() {}, nil
}
// TODO(mrueg): Replace internal/github.com/gddo once https://github.com/golang/go/issues/19307 is implemented.
selected := httputil.NegotiateContentEncoding(r, compressions)
switch selected {
case "zstd":
// TODO(mrueg): Replace klauspost/compress with stdlib implementation once https://github.com/golang/go/issues/62513 is implemented.
z, err := zstd.NewWriter(rw, zstd.WithEncoderLevel(zstd.SpeedFastest))
if err != nil {
return nil, "", func() {}, err
}
z.Reset(rw)
return z, selected, func() { _ = z.Close() }, nil
case "gzip":
gz := gzipPool.Get().(*gzip.Writer)
gz.Reset(rw)
return gz, selected, func() { _ = gz.Close(); gzipPool.Put(gz) }, nil
case "identity":
// This means the content is not compressed.
return rw, selected, func() {}, nil
default:
// The content encoding was not implemented yet.
return nil, "", func() {}, fmt.Errorf("content compression format not recognized: %s. Valid formats are: %s", selected, defaultCompressionFormats)
}
}

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@ -0,0 +1,249 @@
// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"crypto/tls"
"net/http"
"net/http/httptrace"
"time"
"github.com/prometheus/client_golang/prometheus"
)
// The RoundTripperFunc type is an adapter to allow the use of ordinary
// functions as RoundTrippers. If f is a function with the appropriate
// signature, RountTripperFunc(f) is a RoundTripper that calls f.
type RoundTripperFunc func(req *http.Request) (*http.Response, error)
// RoundTrip implements the RoundTripper interface.
func (rt RoundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
return rt(r)
}
// InstrumentRoundTripperInFlight is a middleware that wraps the provided
// http.RoundTripper. It sets the provided prometheus.Gauge to the number of
// requests currently handled by the wrapped http.RoundTripper.
//
// See the example for ExampleInstrumentRoundTripperDuration for example usage.
func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripper) RoundTripperFunc {
return func(r *http.Request) (*http.Response, error) {
gauge.Inc()
defer gauge.Dec()
return next.RoundTrip(r)
}
}
// InstrumentRoundTripperCounter is a middleware that wraps the provided
// http.RoundTripper to observe the request result with the provided CounterVec.
// The CounterVec must have zero, one, or two non-const non-curried labels. For
// those, the only allowed label names are "code" and "method". The function
// panics otherwise. For the "method" label a predefined default label value set
// is used to filter given values. Values besides predefined values will count
// as `unknown` method.`WithExtraMethods` can be used to add more
// methods to the set. Partitioning of the CounterVec happens by HTTP status code
// and/or HTTP method if the respective instance label names are present in the
// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
//
// If the wrapped RoundTripper panics or returns a non-nil error, the Counter
// is not incremented.
//
// Use with WithExemplarFromContext to instrument the exemplars on the counter of requests.
//
// See the example for ExampleInstrumentRoundTripperDuration for example usage.
func InstrumentRoundTripperCounter(counter *prometheus.CounterVec, next http.RoundTripper, opts ...Option) RoundTripperFunc {
rtOpts := defaultOptions()
for _, o := range opts {
o.apply(rtOpts)
}
// Curry the counter with dynamic labels before checking the remaining labels.
code, method := checkLabels(counter.MustCurryWith(rtOpts.emptyDynamicLabels()))
return func(r *http.Request) (*http.Response, error) {
resp, err := next.RoundTrip(r)
if err == nil {
l := labels(code, method, r.Method, resp.StatusCode, rtOpts.extraMethods...)
for label, resolve := range rtOpts.extraLabelsFromCtx {
l[label] = resolve(resp.Request.Context())
}
addWithExemplar(counter.With(l), 1, rtOpts.getExemplarFn(r.Context()))
}
return resp, err
}
}
// InstrumentRoundTripperDuration is a middleware that wraps the provided
// http.RoundTripper to observe the request duration with the provided
// ObserverVec. The ObserverVec must have zero, one, or two non-const
// non-curried labels. For those, the only allowed label names are "code" and
// "method". The function panics otherwise. For the "method" label a predefined
// default label value set is used to filter given values. Values besides
// predefined values will count as `unknown` method. `WithExtraMethods`
// can be used to add more methods to the set. The Observe method of the Observer
// in the ObserverVec is called with the request duration in
// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
// respective instance label names are present in the ObserverVec. For
// unpartitioned observations, use an ObserverVec with zero labels. Note that
// partitioning of Histograms is expensive and should be used judiciously.
//
// If the wrapped RoundTripper panics or returns a non-nil error, no values are
// reported.
//
// Use with WithExemplarFromContext to instrument the exemplars on the duration histograms.
//
// Note that this method is only guaranteed to never observe negative durations
// if used with Go1.9+.
func InstrumentRoundTripperDuration(obs prometheus.ObserverVec, next http.RoundTripper, opts ...Option) RoundTripperFunc {
rtOpts := defaultOptions()
for _, o := range opts {
o.apply(rtOpts)
}
// Curry the observer with dynamic labels before checking the remaining labels.
code, method := checkLabels(obs.MustCurryWith(rtOpts.emptyDynamicLabels()))
return func(r *http.Request) (*http.Response, error) {
start := time.Now()
resp, err := next.RoundTrip(r)
if err == nil {
l := labels(code, method, r.Method, resp.StatusCode, rtOpts.extraMethods...)
for label, resolve := range rtOpts.extraLabelsFromCtx {
l[label] = resolve(resp.Request.Context())
}
observeWithExemplar(obs.With(l), time.Since(start).Seconds(), rtOpts.getExemplarFn(r.Context()))
}
return resp, err
}
}
// InstrumentTrace is used to offer flexibility in instrumenting the available
// httptrace.ClientTrace hook functions. Each function is passed a float64
// representing the time in seconds since the start of the http request. A user
// may choose to use separately buckets Histograms, or implement custom
// instance labels on a per function basis.
type InstrumentTrace struct {
GotConn func(float64)
PutIdleConn func(float64)
GotFirstResponseByte func(float64)
Got100Continue func(float64)
DNSStart func(float64)
DNSDone func(float64)
ConnectStart func(float64)
ConnectDone func(float64)
TLSHandshakeStart func(float64)
TLSHandshakeDone func(float64)
WroteHeaders func(float64)
Wait100Continue func(float64)
WroteRequest func(float64)
}
// InstrumentRoundTripperTrace is a middleware that wraps the provided
// RoundTripper and reports times to hook functions provided in the
// InstrumentTrace struct. Hook functions that are not present in the provided
// InstrumentTrace struct are ignored. Times reported to the hook functions are
// time since the start of the request. Only with Go1.9+, those times are
// guaranteed to never be negative. (Earlier Go versions are not using a
// monotonic clock.) Note that partitioning of Histograms is expensive and
// should be used judiciously.
//
// For hook functions that receive an error as an argument, no observations are
// made in the event of a non-nil error value.
//
// See the example for ExampleInstrumentRoundTripperDuration for example usage.
func InstrumentRoundTripperTrace(it *InstrumentTrace, next http.RoundTripper) RoundTripperFunc {
return func(r *http.Request) (*http.Response, error) {
start := time.Now()
trace := &httptrace.ClientTrace{
GotConn: func(_ httptrace.GotConnInfo) {
if it.GotConn != nil {
it.GotConn(time.Since(start).Seconds())
}
},
PutIdleConn: func(err error) {
if err != nil {
return
}
if it.PutIdleConn != nil {
it.PutIdleConn(time.Since(start).Seconds())
}
},
DNSStart: func(_ httptrace.DNSStartInfo) {
if it.DNSStart != nil {
it.DNSStart(time.Since(start).Seconds())
}
},
DNSDone: func(_ httptrace.DNSDoneInfo) {
if it.DNSDone != nil {
it.DNSDone(time.Since(start).Seconds())
}
},
ConnectStart: func(_, _ string) {
if it.ConnectStart != nil {
it.ConnectStart(time.Since(start).Seconds())
}
},
ConnectDone: func(_, _ string, err error) {
if err != nil {
return
}
if it.ConnectDone != nil {
it.ConnectDone(time.Since(start).Seconds())
}
},
GotFirstResponseByte: func() {
if it.GotFirstResponseByte != nil {
it.GotFirstResponseByte(time.Since(start).Seconds())
}
},
Got100Continue: func() {
if it.Got100Continue != nil {
it.Got100Continue(time.Since(start).Seconds())
}
},
TLSHandshakeStart: func() {
if it.TLSHandshakeStart != nil {
it.TLSHandshakeStart(time.Since(start).Seconds())
}
},
TLSHandshakeDone: func(_ tls.ConnectionState, err error) {
if err != nil {
return
}
if it.TLSHandshakeDone != nil {
it.TLSHandshakeDone(time.Since(start).Seconds())
}
},
WroteHeaders: func() {
if it.WroteHeaders != nil {
it.WroteHeaders(time.Since(start).Seconds())
}
},
Wait100Continue: func() {
if it.Wait100Continue != nil {
it.Wait100Continue(time.Since(start).Seconds())
}
},
WroteRequest: func(_ httptrace.WroteRequestInfo) {
if it.WroteRequest != nil {
it.WroteRequest(time.Since(start).Seconds())
}
},
}
r = r.WithContext(httptrace.WithClientTrace(r.Context(), trace))
return next.RoundTrip(r)
}
}

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@ -0,0 +1,576 @@
// Copyright 2017 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"errors"
"net/http"
"strconv"
"strings"
"time"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/client_golang/prometheus"
)
// magicString is used for the hacky label test in checkLabels. Remove once fixed.
const magicString = "zZgWfBxLqvG8kc8IMv3POi2Bb0tZI3vAnBx+gBaFi9FyPzB/CzKUer1yufDa"
// observeWithExemplar is a wrapper for [prometheus.ExemplarAdder.ExemplarObserver],
// which falls back to [prometheus.Observer.Observe] if no labels are provided.
func observeWithExemplar(obs prometheus.Observer, val float64, labels map[string]string) {
if labels == nil {
obs.Observe(val)
return
}
obs.(prometheus.ExemplarObserver).ObserveWithExemplar(val, labels)
}
// addWithExemplar is a wrapper for [prometheus.ExemplarAdder.AddWithExemplar],
// which falls back to [prometheus.Counter.Add] if no labels are provided.
func addWithExemplar(obs prometheus.Counter, val float64, labels map[string]string) {
if labels == nil {
obs.Add(val)
return
}
obs.(prometheus.ExemplarAdder).AddWithExemplar(val, labels)
}
// InstrumentHandlerInFlight is a middleware that wraps the provided
// http.Handler. It sets the provided prometheus.Gauge to the number of
// requests currently handled by the wrapped http.Handler.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
g.Inc()
defer g.Dec()
next.ServeHTTP(w, r)
})
}
// InstrumentHandlerDuration is a middleware that wraps the provided
// http.Handler to observe the request duration with the provided ObserverVec.
// The ObserverVec must have valid metric and label names and must have zero,
// one, or two non-const non-curried labels. For those, the only allowed label
// names are "code" and "method". The function panics otherwise. For the "method"
// label a predefined default label value set is used to filter given values.
// Values besides predefined values will count as `unknown` method.
// `WithExtraMethods` can be used to add more methods to the set. The Observe
// method of the Observer in the ObserverVec is called with the request duration
// in seconds. Partitioning happens by HTTP status code and/or HTTP method if
// the respective instance label names are present in the ObserverVec. For
// unpartitioned observations, use an ObserverVec with zero labels. Note that
// partitioning of Histograms is expensive and should be used judiciously.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
// If the wrapped Handler panics, no values are reported.
//
// Note that this method is only guaranteed to never observe negative durations
// if used with Go1.9+.
func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler, opts ...Option) http.HandlerFunc {
hOpts := defaultOptions()
for _, o := range opts {
o.apply(hOpts)
}
// Curry the observer with dynamic labels before checking the remaining labels.
code, method := checkLabels(obs.MustCurryWith(hOpts.emptyDynamicLabels()))
if code {
return func(w http.ResponseWriter, r *http.Request) {
now := time.Now()
d := newDelegator(w, nil)
next.ServeHTTP(d, r)
l := labels(code, method, r.Method, d.Status(), hOpts.extraMethods...)
for label, resolve := range hOpts.extraLabelsFromCtx {
l[label] = resolve(r.Context())
}
observeWithExemplar(obs.With(l), time.Since(now).Seconds(), hOpts.getExemplarFn(r.Context()))
}
}
return func(w http.ResponseWriter, r *http.Request) {
now := time.Now()
next.ServeHTTP(w, r)
l := labels(code, method, r.Method, 0, hOpts.extraMethods...)
for label, resolve := range hOpts.extraLabelsFromCtx {
l[label] = resolve(r.Context())
}
observeWithExemplar(obs.With(l), time.Since(now).Seconds(), hOpts.getExemplarFn(r.Context()))
}
}
// InstrumentHandlerCounter is a middleware that wraps the provided http.Handler
// to observe the request result with the provided CounterVec. The CounterVec
// must have valid metric and label names and must have zero, one, or two
// non-const non-curried labels. For those, the only allowed label names are
// "code" and "method". The function panics otherwise. For the "method"
// label a predefined default label value set is used to filter given values.
// Values besides predefined values will count as `unknown` method.
// `WithExtraMethods` can be used to add more methods to the set. Partitioning of the
// CounterVec happens by HTTP status code and/or HTTP method if the respective
// instance label names are present in the CounterVec. For unpartitioned
// counting, use a CounterVec with zero labels.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
// If the wrapped Handler panics, the Counter is not incremented.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler, opts ...Option) http.HandlerFunc {
hOpts := defaultOptions()
for _, o := range opts {
o.apply(hOpts)
}
// Curry the counter with dynamic labels before checking the remaining labels.
code, method := checkLabels(counter.MustCurryWith(hOpts.emptyDynamicLabels()))
if code {
return func(w http.ResponseWriter, r *http.Request) {
d := newDelegator(w, nil)
next.ServeHTTP(d, r)
l := labels(code, method, r.Method, d.Status(), hOpts.extraMethods...)
for label, resolve := range hOpts.extraLabelsFromCtx {
l[label] = resolve(r.Context())
}
addWithExemplar(counter.With(l), 1, hOpts.getExemplarFn(r.Context()))
}
}
return func(w http.ResponseWriter, r *http.Request) {
next.ServeHTTP(w, r)
l := labels(code, method, r.Method, 0, hOpts.extraMethods...)
for label, resolve := range hOpts.extraLabelsFromCtx {
l[label] = resolve(r.Context())
}
addWithExemplar(counter.With(l), 1, hOpts.getExemplarFn(r.Context()))
}
}
// InstrumentHandlerTimeToWriteHeader is a middleware that wraps the provided
// http.Handler to observe with the provided ObserverVec the request duration
// until the response headers are written. The ObserverVec must have valid
// metric and label names and must have zero, one, or two non-const non-curried
// labels. For those, the only allowed label names are "code" and "method". The
// function panics otherwise. For the "method" label a predefined default label
// value set is used to filter given values. Values besides predefined values
// will count as `unknown` method.`WithExtraMethods` can be used to add more
// methods to the set. The Observe method of the Observer in the
// ObserverVec is called with the request duration in seconds. Partitioning
// happens by HTTP status code and/or HTTP method if the respective instance
// label names are present in the ObserverVec. For unpartitioned observations,
// use an ObserverVec with zero labels. Note that partitioning of Histograms is
// expensive and should be used judiciously.
//
// If the wrapped Handler panics before calling WriteHeader, no value is
// reported.
//
// Note that this method is only guaranteed to never observe negative durations
// if used with Go1.9+.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Handler, opts ...Option) http.HandlerFunc {
hOpts := defaultOptions()
for _, o := range opts {
o.apply(hOpts)
}
// Curry the observer with dynamic labels before checking the remaining labels.
code, method := checkLabels(obs.MustCurryWith(hOpts.emptyDynamicLabels()))
return func(w http.ResponseWriter, r *http.Request) {
now := time.Now()
d := newDelegator(w, func(status int) {
l := labels(code, method, r.Method, status, hOpts.extraMethods...)
for label, resolve := range hOpts.extraLabelsFromCtx {
l[label] = resolve(r.Context())
}
observeWithExemplar(obs.With(l), time.Since(now).Seconds(), hOpts.getExemplarFn(r.Context()))
})
next.ServeHTTP(d, r)
}
}
// InstrumentHandlerRequestSize is a middleware that wraps the provided
// http.Handler to observe the request size with the provided ObserverVec. The
// ObserverVec must have valid metric and label names and must have zero, one,
// or two non-const non-curried labels. For those, the only allowed label names
// are "code" and "method". The function panics otherwise. For the "method"
// label a predefined default label value set is used to filter given values.
// Values besides predefined values will count as `unknown` method.
// `WithExtraMethods` can be used to add more methods to the set. The Observe
// method of the Observer in the ObserverVec is called with the request size in
// bytes. Partitioning happens by HTTP status code and/or HTTP method if the
// respective instance label names are present in the ObserverVec. For
// unpartitioned observations, use an ObserverVec with zero labels. Note that
// partitioning of Histograms is expensive and should be used judiciously.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
// If the wrapped Handler panics, no values are reported.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler, opts ...Option) http.HandlerFunc {
hOpts := defaultOptions()
for _, o := range opts {
o.apply(hOpts)
}
// Curry the observer with dynamic labels before checking the remaining labels.
code, method := checkLabels(obs.MustCurryWith(hOpts.emptyDynamicLabels()))
if code {
return func(w http.ResponseWriter, r *http.Request) {
d := newDelegator(w, nil)
next.ServeHTTP(d, r)
size := computeApproximateRequestSize(r)
l := labels(code, method, r.Method, d.Status(), hOpts.extraMethods...)
for label, resolve := range hOpts.extraLabelsFromCtx {
l[label] = resolve(r.Context())
}
observeWithExemplar(obs.With(l), float64(size), hOpts.getExemplarFn(r.Context()))
}
}
return func(w http.ResponseWriter, r *http.Request) {
next.ServeHTTP(w, r)
size := computeApproximateRequestSize(r)
l := labels(code, method, r.Method, 0, hOpts.extraMethods...)
for label, resolve := range hOpts.extraLabelsFromCtx {
l[label] = resolve(r.Context())
}
observeWithExemplar(obs.With(l), float64(size), hOpts.getExemplarFn(r.Context()))
}
}
// InstrumentHandlerResponseSize is a middleware that wraps the provided
// http.Handler to observe the response size with the provided ObserverVec. The
// ObserverVec must have valid metric and label names and must have zero, one,
// or two non-const non-curried labels. For those, the only allowed label names
// are "code" and "method". The function panics otherwise. For the "method"
// label a predefined default label value set is used to filter given values.
// Values besides predefined values will count as `unknown` method.
// `WithExtraMethods` can be used to add more methods to the set. The Observe
// method of the Observer in the ObserverVec is called with the response size in
// bytes. Partitioning happens by HTTP status code and/or HTTP method if the
// respective instance label names are present in the ObserverVec. For
// unpartitioned observations, use an ObserverVec with zero labels. Note that
// partitioning of Histograms is expensive and should be used judiciously.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
// If the wrapped Handler panics, no values are reported.
//
// See the example for InstrumentHandlerDuration for example usage.
func InstrumentHandlerResponseSize(obs prometheus.ObserverVec, next http.Handler, opts ...Option) http.Handler {
hOpts := defaultOptions()
for _, o := range opts {
o.apply(hOpts)
}
// Curry the observer with dynamic labels before checking the remaining labels.
code, method := checkLabels(obs.MustCurryWith(hOpts.emptyDynamicLabels()))
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
d := newDelegator(w, nil)
next.ServeHTTP(d, r)
l := labels(code, method, r.Method, d.Status(), hOpts.extraMethods...)
for label, resolve := range hOpts.extraLabelsFromCtx {
l[label] = resolve(r.Context())
}
observeWithExemplar(obs.With(l), float64(d.Written()), hOpts.getExemplarFn(r.Context()))
})
}
// checkLabels returns whether the provided Collector has a non-const,
// non-curried label named "code" and/or "method". It panics if the provided
// Collector does not have a Desc or has more than one Desc or its Desc is
// invalid. It also panics if the Collector has any non-const, non-curried
// labels that are not named "code" or "method".
func checkLabels(c prometheus.Collector) (code, method bool) {
// TODO(beorn7): Remove this hacky way to check for instance labels
// once Descriptors can have their dimensionality queried.
var (
desc *prometheus.Desc
m prometheus.Metric
pm dto.Metric
lvs []string
)
// Get the Desc from the Collector.
descc := make(chan *prometheus.Desc, 1)
c.Describe(descc)
select {
case desc = <-descc:
default:
panic("no description provided by collector")
}
select {
case <-descc:
panic("more than one description provided by collector")
default:
}
close(descc)
// Make sure the Collector has a valid Desc by registering it with a
// temporary registry.
prometheus.NewRegistry().MustRegister(c)
// Create a ConstMetric with the Desc. Since we don't know how many
// variable labels there are, try for as long as it needs.
for err := errors.New("dummy"); err != nil; lvs = append(lvs, magicString) {
m, err = prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, lvs...)
}
// Write out the metric into a proto message and look at the labels.
// If the value is not the magicString, it is a constLabel, which doesn't interest us.
// If the label is curried, it doesn't interest us.
// In all other cases, only "code" or "method" is allowed.
if err := m.Write(&pm); err != nil {
panic("error checking metric for labels")
}
for _, label := range pm.Label {
name, value := label.GetName(), label.GetValue()
if value != magicString || isLabelCurried(c, name) {
continue
}
switch name {
case "code":
code = true
case "method":
method = true
default:
panic("metric partitioned with non-supported labels")
}
}
return
}
func isLabelCurried(c prometheus.Collector, label string) bool {
// This is even hackier than the label test above.
// We essentially try to curry again and see if it works.
// But for that, we need to type-convert to the two
// types we use here, ObserverVec or *CounterVec.
switch v := c.(type) {
case *prometheus.CounterVec:
if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
return false
}
case prometheus.ObserverVec:
if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
return false
}
default:
panic("unsupported metric vec type")
}
return true
}
func labels(code, method bool, reqMethod string, status int, extraMethods ...string) prometheus.Labels {
labels := prometheus.Labels{}
if !(code || method) {
return labels
}
if code {
labels["code"] = sanitizeCode(status)
}
if method {
labels["method"] = sanitizeMethod(reqMethod, extraMethods...)
}
return labels
}
func computeApproximateRequestSize(r *http.Request) int {
s := 0
if r.URL != nil {
s += len(r.URL.String())
}
s += len(r.Method)
s += len(r.Proto)
for name, values := range r.Header {
s += len(name)
for _, value := range values {
s += len(value)
}
}
s += len(r.Host)
// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
if r.ContentLength != -1 {
s += int(r.ContentLength)
}
return s
}
// If the wrapped http.Handler has a known method, it will be sanitized and returned.
// Otherwise, "unknown" will be returned. The known method list can be extended
// as needed by using extraMethods parameter.
func sanitizeMethod(m string, extraMethods ...string) string {
// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods for
// the methods chosen as default.
switch m {
case "GET", "get":
return "get"
case "PUT", "put":
return "put"
case "HEAD", "head":
return "head"
case "POST", "post":
return "post"
case "DELETE", "delete":
return "delete"
case "CONNECT", "connect":
return "connect"
case "OPTIONS", "options":
return "options"
case "NOTIFY", "notify":
return "notify"
case "TRACE", "trace":
return "trace"
case "PATCH", "patch":
return "patch"
default:
for _, method := range extraMethods {
if strings.EqualFold(m, method) {
return strings.ToLower(m)
}
}
return "unknown"
}
}
// If the wrapped http.Handler has not set a status code, i.e. the value is
// currently 0, sanitizeCode will return 200, for consistency with behavior in
// the stdlib.
func sanitizeCode(s int) string {
// See for accepted codes https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml
switch s {
case 100:
return "100"
case 101:
return "101"
case 200, 0:
return "200"
case 201:
return "201"
case 202:
return "202"
case 203:
return "203"
case 204:
return "204"
case 205:
return "205"
case 206:
return "206"
case 300:
return "300"
case 301:
return "301"
case 302:
return "302"
case 304:
return "304"
case 305:
return "305"
case 307:
return "307"
case 400:
return "400"
case 401:
return "401"
case 402:
return "402"
case 403:
return "403"
case 404:
return "404"
case 405:
return "405"
case 406:
return "406"
case 407:
return "407"
case 408:
return "408"
case 409:
return "409"
case 410:
return "410"
case 411:
return "411"
case 412:
return "412"
case 413:
return "413"
case 414:
return "414"
case 415:
return "415"
case 416:
return "416"
case 417:
return "417"
case 418:
return "418"
case 500:
return "500"
case 501:
return "501"
case 502:
return "502"
case 503:
return "503"
case 504:
return "504"
case 505:
return "505"
case 428:
return "428"
case 429:
return "429"
case 431:
return "431"
case 511:
return "511"
default:
if s >= 100 && s <= 599 {
return strconv.Itoa(s)
}
return "unknown"
}
}

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@ -0,0 +1,84 @@
// Copyright 2022 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promhttp
import (
"context"
"github.com/prometheus/client_golang/prometheus"
)
// Option are used to configure both handler (middleware) or round tripper.
type Option interface {
apply(*options)
}
// LabelValueFromCtx are used to compute the label value from request context.
// Context can be filled with values from request through middleware.
type LabelValueFromCtx func(ctx context.Context) string
// options store options for both a handler or round tripper.
type options struct {
extraMethods []string
getExemplarFn func(requestCtx context.Context) prometheus.Labels
extraLabelsFromCtx map[string]LabelValueFromCtx
}
func defaultOptions() *options {
return &options{
getExemplarFn: func(ctx context.Context) prometheus.Labels { return nil },
extraLabelsFromCtx: map[string]LabelValueFromCtx{},
}
}
func (o *options) emptyDynamicLabels() prometheus.Labels {
labels := prometheus.Labels{}
for label := range o.extraLabelsFromCtx {
labels[label] = ""
}
return labels
}
type optionApplyFunc func(*options)
func (o optionApplyFunc) apply(opt *options) { o(opt) }
// WithExtraMethods adds additional HTTP methods to the list of allowed methods.
// See https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods for the default list.
//
// See the example for ExampleInstrumentHandlerWithExtraMethods for example usage.
func WithExtraMethods(methods ...string) Option {
return optionApplyFunc(func(o *options) {
o.extraMethods = methods
})
}
// WithExemplarFromContext allows to inject function that will get exemplar from context that will be put to counter and histogram metrics.
// If the function returns nil labels or the metric does not support exemplars, no exemplar will be added (noop), but
// metric will continue to observe/increment.
func WithExemplarFromContext(getExemplarFn func(requestCtx context.Context) prometheus.Labels) Option {
return optionApplyFunc(func(o *options) {
o.getExemplarFn = getExemplarFn
})
}
// WithLabelFromCtx registers a label for dynamic resolution with access to context.
// See the example for ExampleInstrumentHandlerWithLabelResolver for example usage
func WithLabelFromCtx(name string, valueFn LabelValueFromCtx) Option {
return optionApplyFunc(func(o *options) {
o.extraLabelsFromCtx[name] = valueFn
})
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"math"
"runtime"
"sort"
"sync"
"sync/atomic"
"time"
dto "github.com/prometheus/client_model/go"
"github.com/beorn7/perks/quantile"
"google.golang.org/protobuf/proto"
"google.golang.org/protobuf/types/known/timestamppb"
)
// quantileLabel is used for the label that defines the quantile in a
// summary.
const quantileLabel = "quantile"
// A Summary captures individual observations from an event or sample stream and
// summarizes them in a manner similar to traditional summary statistics: 1. sum
// of observations, 2. observation count, 3. rank estimations.
//
// A typical use-case is the observation of request latencies. By default, a
// Summary provides the median, the 90th and the 99th percentile of the latency
// as rank estimations. However, the default behavior will change in the
// upcoming v1.0.0 of the library. There will be no rank estimations at all by
// default. For a sane transition, it is recommended to set the desired rank
// estimations explicitly.
//
// Note that the rank estimations cannot be aggregated in a meaningful way with
// the Prometheus query language (i.e. you cannot average or add them). If you
// need aggregatable quantiles (e.g. you want the 99th percentile latency of all
// queries served across all instances of a service), consider the Histogram
// metric type. See the Prometheus documentation for more details.
//
// To create Summary instances, use NewSummary.
type Summary interface {
Metric
Collector
// Observe adds a single observation to the summary. Observations are
// usually positive or zero. Negative observations are accepted but
// prevent current versions of Prometheus from properly detecting
// counter resets in the sum of observations. See
// https://prometheus.io/docs/practices/histograms/#count-and-sum-of-observations
// for details.
Observe(float64)
}
var errQuantileLabelNotAllowed = fmt.Errorf(
"%q is not allowed as label name in summaries", quantileLabel,
)
// Default values for SummaryOpts.
const (
// DefMaxAge is the default duration for which observations stay
// relevant.
DefMaxAge time.Duration = 10 * time.Minute
// DefAgeBuckets is the default number of buckets used to calculate the
// age of observations.
DefAgeBuckets = 5
// DefBufCap is the standard buffer size for collecting Summary observations.
DefBufCap = 500
)
// SummaryOpts bundles the options for creating a Summary metric. It is
// mandatory to set Name to a non-empty string. While all other fields are
// optional and can safely be left at their zero value, it is recommended to set
// a help string and to explicitly set the Objectives field to the desired value
// as the default value will change in the upcoming v1.0.0 of the library.
type SummaryOpts struct {
// Namespace, Subsystem, and Name are components of the fully-qualified
// name of the Summary (created by joining these components with
// "_"). Only Name is mandatory, the others merely help structuring the
// name. Note that the fully-qualified name of the Summary must be a
// valid Prometheus metric name.
Namespace string
Subsystem string
Name string
// Help provides information about this Summary.
//
// Metrics with the same fully-qualified name must have the same Help
// string.
Help string
// ConstLabels are used to attach fixed labels to this metric. Metrics
// with the same fully-qualified name must have the same label names in
// their ConstLabels.
//
// Due to the way a Summary is represented in the Prometheus text format
// and how it is handled by the Prometheus server internally, “quantile”
// is an illegal label name. Construction of a Summary or SummaryVec
// will panic if this label name is used in ConstLabels.
//
// ConstLabels are only used rarely. In particular, do not use them to
// attach the same labels to all your metrics. Those use cases are
// better covered by target labels set by the scraping Prometheus
// server, or by one specific metric (e.g. a build_info or a
// machine_role metric). See also
// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels-not-static-scraped-labels
ConstLabels Labels
// Objectives defines the quantile rank estimates with their respective
// absolute error. If Objectives[q] = e, then the value reported for q
// will be the φ-quantile value for some φ between q-e and q+e. The
// default value is an empty map, resulting in a summary without
// quantiles.
Objectives map[float64]float64
// MaxAge defines the duration for which an observation stays relevant
// for the summary. Only applies to pre-calculated quantiles, does not
// apply to _sum and _count. Must be positive. The default value is
// DefMaxAge.
MaxAge time.Duration
// AgeBuckets is the number of buckets used to exclude observations that
// are older than MaxAge from the summary. A higher number has a
// resource penalty, so only increase it if the higher resolution is
// really required. For very high observation rates, you might want to
// reduce the number of age buckets. With only one age bucket, you will
// effectively see a complete reset of the summary each time MaxAge has
// passed. The default value is DefAgeBuckets.
AgeBuckets uint32
// BufCap defines the default sample stream buffer size. The default
// value of DefBufCap should suffice for most uses. If there is a need
// to increase the value, a multiple of 500 is recommended (because that
// is the internal buffer size of the underlying package
// "github.com/bmizerany/perks/quantile").
BufCap uint32
// now is for testing purposes, by default it's time.Now.
now func() time.Time
}
// SummaryVecOpts bundles the options to create a SummaryVec metric.
// It is mandatory to set SummaryOpts, see there for mandatory fields. VariableLabels
// is optional and can safely be left to its default value.
type SummaryVecOpts struct {
SummaryOpts
// VariableLabels are used to partition the metric vector by the given set
// of labels. Each label value will be constrained with the optional Constraint
// function, if provided.
VariableLabels ConstrainableLabels
}
// Problem with the sliding-window decay algorithm... The Merge method of
// perk/quantile is actually not working as advertised - and it might be
// unfixable, as the underlying algorithm is apparently not capable of merging
// summaries in the first place. To avoid using Merge, we are currently adding
// observations to _each_ age bucket, i.e. the effort to add a sample is
// essentially multiplied by the number of age buckets. When rotating age
// buckets, we empty the previous head stream. On scrape time, we simply take
// the quantiles from the head stream (no merging required). Result: More effort
// on observation time, less effort on scrape time, which is exactly the
// opposite of what we try to accomplish, but at least the results are correct.
//
// The quite elegant previous contraption to merge the age buckets efficiently
// on scrape time (see code up commit 6b9530d72ea715f0ba612c0120e6e09fbf1d49d0)
// can't be used anymore.
// NewSummary creates a new Summary based on the provided SummaryOpts.
func NewSummary(opts SummaryOpts) Summary {
return newSummary(
NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
),
opts,
)
}
func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
if len(desc.variableLabels.names) != len(labelValues) {
panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels.names, labelValues))
}
for _, n := range desc.variableLabels.names {
if n == quantileLabel {
panic(errQuantileLabelNotAllowed)
}
}
for _, lp := range desc.constLabelPairs {
if lp.GetName() == quantileLabel {
panic(errQuantileLabelNotAllowed)
}
}
if opts.Objectives == nil {
opts.Objectives = map[float64]float64{}
}
if opts.MaxAge < 0 {
panic(fmt.Errorf("illegal max age MaxAge=%v", opts.MaxAge))
}
if opts.MaxAge == 0 {
opts.MaxAge = DefMaxAge
}
if opts.AgeBuckets == 0 {
opts.AgeBuckets = DefAgeBuckets
}
if opts.BufCap == 0 {
opts.BufCap = DefBufCap
}
if opts.now == nil {
opts.now = time.Now
}
if len(opts.Objectives) == 0 {
// Use the lock-free implementation of a Summary without objectives.
s := &noObjectivesSummary{
desc: desc,
labelPairs: MakeLabelPairs(desc, labelValues),
counts: [2]*summaryCounts{{}, {}},
}
s.init(s) // Init self-collection.
s.createdTs = timestamppb.New(opts.now())
return s
}
s := &summary{
desc: desc,
now: opts.now,
objectives: opts.Objectives,
sortedObjectives: make([]float64, 0, len(opts.Objectives)),
labelPairs: MakeLabelPairs(desc, labelValues),
hotBuf: make([]float64, 0, opts.BufCap),
coldBuf: make([]float64, 0, opts.BufCap),
streamDuration: opts.MaxAge / time.Duration(opts.AgeBuckets),
}
s.headStreamExpTime = opts.now().Add(s.streamDuration)
s.hotBufExpTime = s.headStreamExpTime
for i := uint32(0); i < opts.AgeBuckets; i++ {
s.streams = append(s.streams, s.newStream())
}
s.headStream = s.streams[0]
for qu := range s.objectives {
s.sortedObjectives = append(s.sortedObjectives, qu)
}
sort.Float64s(s.sortedObjectives)
s.init(s) // Init self-collection.
s.createdTs = timestamppb.New(opts.now())
return s
}
type summary struct {
selfCollector
bufMtx sync.Mutex // Protects hotBuf and hotBufExpTime.
mtx sync.Mutex // Protects every other moving part.
// Lock bufMtx before mtx if both are needed.
desc *Desc
now func() time.Time
objectives map[float64]float64
sortedObjectives []float64
labelPairs []*dto.LabelPair
sum float64
cnt uint64
hotBuf, coldBuf []float64
streams []*quantile.Stream
streamDuration time.Duration
headStream *quantile.Stream
headStreamIdx int
headStreamExpTime, hotBufExpTime time.Time
createdTs *timestamppb.Timestamp
}
func (s *summary) Desc() *Desc {
return s.desc
}
func (s *summary) Observe(v float64) {
s.bufMtx.Lock()
defer s.bufMtx.Unlock()
now := s.now()
if now.After(s.hotBufExpTime) {
s.asyncFlush(now)
}
s.hotBuf = append(s.hotBuf, v)
if len(s.hotBuf) == cap(s.hotBuf) {
s.asyncFlush(now)
}
}
func (s *summary) Write(out *dto.Metric) error {
sum := &dto.Summary{
CreatedTimestamp: s.createdTs,
}
qs := make([]*dto.Quantile, 0, len(s.objectives))
s.bufMtx.Lock()
s.mtx.Lock()
// Swap bufs even if hotBuf is empty to set new hotBufExpTime.
s.swapBufs(s.now())
s.bufMtx.Unlock()
s.flushColdBuf()
sum.SampleCount = proto.Uint64(s.cnt)
sum.SampleSum = proto.Float64(s.sum)
for _, rank := range s.sortedObjectives {
var q float64
if s.headStream.Count() == 0 {
q = math.NaN()
} else {
q = s.headStream.Query(rank)
}
qs = append(qs, &dto.Quantile{
Quantile: proto.Float64(rank),
Value: proto.Float64(q),
})
}
s.mtx.Unlock()
if len(qs) > 0 {
sort.Sort(quantSort(qs))
}
sum.Quantile = qs
out.Summary = sum
out.Label = s.labelPairs
return nil
}
func (s *summary) newStream() *quantile.Stream {
return quantile.NewTargeted(s.objectives)
}
// asyncFlush needs bufMtx locked.
func (s *summary) asyncFlush(now time.Time) {
s.mtx.Lock()
s.swapBufs(now)
// Unblock the original goroutine that was responsible for the mutation
// that triggered the compaction. But hold onto the global non-buffer
// state mutex until the operation finishes.
go func() {
s.flushColdBuf()
s.mtx.Unlock()
}()
}
// rotateStreams needs mtx AND bufMtx locked.
func (s *summary) maybeRotateStreams() {
for !s.hotBufExpTime.Equal(s.headStreamExpTime) {
s.headStream.Reset()
s.headStreamIdx++
if s.headStreamIdx >= len(s.streams) {
s.headStreamIdx = 0
}
s.headStream = s.streams[s.headStreamIdx]
s.headStreamExpTime = s.headStreamExpTime.Add(s.streamDuration)
}
}
// flushColdBuf needs mtx locked.
func (s *summary) flushColdBuf() {
for _, v := range s.coldBuf {
for _, stream := range s.streams {
stream.Insert(v)
}
s.cnt++
s.sum += v
}
s.coldBuf = s.coldBuf[0:0]
s.maybeRotateStreams()
}
// swapBufs needs mtx AND bufMtx locked, coldBuf must be empty.
func (s *summary) swapBufs(now time.Time) {
if len(s.coldBuf) != 0 {
panic("coldBuf is not empty")
}
s.hotBuf, s.coldBuf = s.coldBuf, s.hotBuf
// hotBuf is now empty and gets new expiration set.
for now.After(s.hotBufExpTime) {
s.hotBufExpTime = s.hotBufExpTime.Add(s.streamDuration)
}
}
type summaryCounts struct {
// sumBits contains the bits of the float64 representing the sum of all
// observations. sumBits and count have to go first in the struct to
// guarantee alignment for atomic operations.
// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
sumBits uint64
count uint64
}
type noObjectivesSummary struct {
// countAndHotIdx enables lock-free writes with use of atomic updates.
// The most significant bit is the hot index [0 or 1] of the count field
// below. Observe calls update the hot one. All remaining bits count the
// number of Observe calls. Observe starts by incrementing this counter,
// and finish by incrementing the count field in the respective
// summaryCounts, as a marker for completion.
//
// Calls of the Write method (which are non-mutating reads from the
// perspective of the summary) swap the hotcold under the writeMtx
// lock. A cooldown is awaited (while locked) by comparing the number of
// observations with the initiation count. Once they match, then the
// last observation on the now cool one has completed. All cool fields must
// be merged into the new hot before releasing writeMtx.
// Fields with atomic access first! See alignment constraint:
// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
countAndHotIdx uint64
selfCollector
desc *Desc
writeMtx sync.Mutex // Only used in the Write method.
// Two counts, one is "hot" for lock-free observations, the other is
// "cold" for writing out a dto.Metric. It has to be an array of
// pointers to guarantee 64bit alignment of the histogramCounts, see
// http://golang.org/pkg/sync/atomic/#pkg-note-BUG.
counts [2]*summaryCounts
labelPairs []*dto.LabelPair
createdTs *timestamppb.Timestamp
}
func (s *noObjectivesSummary) Desc() *Desc {
return s.desc
}
func (s *noObjectivesSummary) Observe(v float64) {
// We increment h.countAndHotIdx so that the counter in the lower
// 63 bits gets incremented. At the same time, we get the new value
// back, which we can use to find the currently-hot counts.
n := atomic.AddUint64(&s.countAndHotIdx, 1)
hotCounts := s.counts[n>>63]
atomicUpdateFloat(&hotCounts.sumBits, func(oldVal float64) float64 {
return oldVal + v
})
// Increment count last as we take it as a signal that the observation
// is complete.
atomic.AddUint64(&hotCounts.count, 1)
}
func (s *noObjectivesSummary) Write(out *dto.Metric) error {
// For simplicity, we protect this whole method by a mutex. It is not in
// the hot path, i.e. Observe is called much more often than Write. The
// complication of making Write lock-free isn't worth it, if possible at
// all.
s.writeMtx.Lock()
defer s.writeMtx.Unlock()
// Adding 1<<63 switches the hot index (from 0 to 1 or from 1 to 0)
// without touching the count bits. See the struct comments for a full
// description of the algorithm.
n := atomic.AddUint64(&s.countAndHotIdx, 1<<63)
// count is contained unchanged in the lower 63 bits.
count := n & ((1 << 63) - 1)
// The most significant bit tells us which counts is hot. The complement
// is thus the cold one.
hotCounts := s.counts[n>>63]
coldCounts := s.counts[(^n)>>63]
// Await cooldown.
for count != atomic.LoadUint64(&coldCounts.count) {
runtime.Gosched() // Let observations get work done.
}
sum := &dto.Summary{
SampleCount: proto.Uint64(count),
SampleSum: proto.Float64(math.Float64frombits(atomic.LoadUint64(&coldCounts.sumBits))),
CreatedTimestamp: s.createdTs,
}
out.Summary = sum
out.Label = s.labelPairs
// Finally add all the cold counts to the new hot counts and reset the cold counts.
atomic.AddUint64(&hotCounts.count, count)
atomic.StoreUint64(&coldCounts.count, 0)
// Use atomicUpdateFloat to update hotCounts.sumBits atomically.
atomicUpdateFloat(&hotCounts.sumBits, func(oldVal float64) float64 {
return oldVal + sum.GetSampleSum()
})
atomic.StoreUint64(&coldCounts.sumBits, 0)
return nil
}
type quantSort []*dto.Quantile
func (s quantSort) Len() int {
return len(s)
}
func (s quantSort) Swap(i, j int) {
s[i], s[j] = s[j], s[i]
}
func (s quantSort) Less(i, j int) bool {
return s[i].GetQuantile() < s[j].GetQuantile()
}
// SummaryVec is a Collector that bundles a set of Summaries that all share the
// same Desc, but have different values for their variable labels. This is used
// if you want to count the same thing partitioned by various dimensions
// (e.g. HTTP request latencies, partitioned by status code and method). Create
// instances with NewSummaryVec.
type SummaryVec struct {
*MetricVec
}
// NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and
// partitioned by the given label names.
//
// Due to the way a Summary is represented in the Prometheus text format and how
// it is handled by the Prometheus server internally, “quantile” is an illegal
// label name. NewSummaryVec will panic if this label name is used.
func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
return V2.NewSummaryVec(SummaryVecOpts{
SummaryOpts: opts,
VariableLabels: UnconstrainedLabels(labelNames),
})
}
// NewSummaryVec creates a new SummaryVec based on the provided SummaryVecOpts.
func (v2) NewSummaryVec(opts SummaryVecOpts) *SummaryVec {
for _, ln := range opts.VariableLabels.labelNames() {
if ln == quantileLabel {
panic(errQuantileLabelNotAllowed)
}
}
desc := V2.NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
opts.VariableLabels,
opts.ConstLabels,
)
return &SummaryVec{
MetricVec: NewMetricVec(desc, func(lvs ...string) Metric {
return newSummary(desc, opts.SummaryOpts, lvs...)
}),
}
}
// GetMetricWithLabelValues returns the Summary for the given slice of label
// values (same order as the variable labels in Desc). If that combination of
// label values is accessed for the first time, a new Summary is created.
//
// It is possible to call this method without using the returned Summary to only
// create the new Summary but leave it at its starting value, a Summary without
// any observations.
//
// Keeping the Summary for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Summary from the SummaryVec. In that case,
// the Summary will still exist, but it will not be exported anymore, even if a
// Summary with the same label values is created later. See also the CounterVec
// example.
//
// An error is returned if the number of label values is not the same as the
// number of variable labels in Desc (minus any curried labels).
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the GaugeVec example.
func (v *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
metric, err := v.MetricVec.GetMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Observer), err
}
return nil, err
}
// GetMetricWith returns the Summary for the given Labels map (the label names
// must match those of the variable labels in Desc). If that label map is
// accessed for the first time, a new Summary is created. Implications of
// creating a Summary without using it and keeping the Summary for later use are
// the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the variable labels in Desc (minus any curried labels).
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
func (v *SummaryVec) GetMetricWith(labels Labels) (Observer, error) {
metric, err := v.MetricVec.GetMetricWith(labels)
if metric != nil {
return metric.(Observer), err
}
return nil, err
}
// WithLabelValues works as GetMetricWithLabelValues, but panics where
// GetMetricWithLabelValues would have returned an error. Not returning an
// error allows shortcuts like
//
// myVec.WithLabelValues("404", "GET").Observe(42.21)
func (v *SummaryVec) WithLabelValues(lvs ...string) Observer {
s, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return s
}
// With works as GetMetricWith, but panics where GetMetricWithLabels would have
// returned an error. Not returning an error allows shortcuts like
//
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
func (v *SummaryVec) With(labels Labels) Observer {
s, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return s
}
// CurryWith returns a vector curried with the provided labels, i.e. the
// returned vector has those labels pre-set for all labeled operations performed
// on it. The cardinality of the curried vector is reduced accordingly. The
// order of the remaining labels stays the same (just with the curried labels
// taken out of the sequence which is relevant for the
// (GetMetric)WithLabelValues methods). It is possible to curry a curried
// vector, but only with labels not yet used for currying before.
//
// The metrics contained in the SummaryVec are shared between the curried and
// uncurried vectors. They are just accessed differently. Curried and uncurried
// vectors behave identically in terms of collection. Only one must be
// registered with a given registry (usually the uncurried version). The Reset
// method deletes all metrics, even if called on a curried vector.
func (v *SummaryVec) CurryWith(labels Labels) (ObserverVec, error) {
vec, err := v.MetricVec.CurryWith(labels)
if vec != nil {
return &SummaryVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *SummaryVec) MustCurryWith(labels Labels) ObserverVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
type constSummary struct {
desc *Desc
count uint64
sum float64
quantiles map[float64]float64
labelPairs []*dto.LabelPair
createdTs *timestamppb.Timestamp
}
func (s *constSummary) Desc() *Desc {
return s.desc
}
func (s *constSummary) Write(out *dto.Metric) error {
sum := &dto.Summary{
CreatedTimestamp: s.createdTs,
}
qs := make([]*dto.Quantile, 0, len(s.quantiles))
sum.SampleCount = proto.Uint64(s.count)
sum.SampleSum = proto.Float64(s.sum)
for rank, q := range s.quantiles {
qs = append(qs, &dto.Quantile{
Quantile: proto.Float64(rank),
Value: proto.Float64(q),
})
}
if len(qs) > 0 {
sort.Sort(quantSort(qs))
}
sum.Quantile = qs
out.Summary = sum
out.Label = s.labelPairs
return nil
}
// NewConstSummary returns a metric representing a Prometheus summary with fixed
// values for the count, sum, and quantiles. As those parameters cannot be
// changed, the returned value does not implement the Summary interface (but
// only the Metric interface). Users of this package will not have much use for
// it in regular operations. However, when implementing custom Collectors, it is
// useful as a throw-away metric that is generated on the fly to send it to
// Prometheus in the Collect method.
//
// quantiles maps ranks to quantile values. For example, a median latency of
// 0.23s and a 99th percentile latency of 0.56s would be expressed as:
//
// map[float64]float64{0.5: 0.23, 0.99: 0.56}
//
// NewConstSummary returns an error if the length of labelValues is not
// consistent with the variable labels in Desc or if Desc is invalid.
func NewConstSummary(
desc *Desc,
count uint64,
sum float64,
quantiles map[float64]float64,
labelValues ...string,
) (Metric, error) {
if desc.err != nil {
return nil, desc.err
}
if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
return nil, err
}
return &constSummary{
desc: desc,
count: count,
sum: sum,
quantiles: quantiles,
labelPairs: MakeLabelPairs(desc, labelValues),
}, nil
}
// MustNewConstSummary is a version of NewConstSummary that panics where
// NewConstMetric would have returned an error.
func MustNewConstSummary(
desc *Desc,
count uint64,
sum float64,
quantiles map[float64]float64,
labelValues ...string,
) Metric {
m, err := NewConstSummary(desc, count, sum, quantiles, labelValues...)
if err != nil {
panic(err)
}
return m
}
// NewConstSummaryWithCreatedTimestamp does the same thing as NewConstSummary but sets the created timestamp.
func NewConstSummaryWithCreatedTimestamp(
desc *Desc,
count uint64,
sum float64,
quantiles map[float64]float64,
ct time.Time,
labelValues ...string,
) (Metric, error) {
if desc.err != nil {
return nil, desc.err
}
if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
return nil, err
}
return &constSummary{
desc: desc,
count: count,
sum: sum,
quantiles: quantiles,
labelPairs: MakeLabelPairs(desc, labelValues),
createdTs: timestamppb.New(ct),
}, nil
}
// MustNewConstSummaryWithCreatedTimestamp is a version of NewConstSummaryWithCreatedTimestamp that panics where
// NewConstSummaryWithCreatedTimestamp would have returned an error.
func MustNewConstSummaryWithCreatedTimestamp(
desc *Desc,
count uint64,
sum float64,
quantiles map[float64]float64,
ct time.Time,
labelValues ...string,
) Metric {
m, err := NewConstSummaryWithCreatedTimestamp(desc, count, sum, quantiles, ct, labelValues...)
if err != nil {
panic(err)
}
return m
}

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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package testutil
import (
"fmt"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/testutil/promlint"
)
// CollectAndLint registers the provided Collector with a newly created pedantic
// Registry. It then calls GatherAndLint with that Registry and with the
// provided metricNames.
func CollectAndLint(c prometheus.Collector, metricNames ...string) ([]promlint.Problem, error) {
reg := prometheus.NewPedanticRegistry()
if err := reg.Register(c); err != nil {
return nil, fmt.Errorf("registering collector failed: %w", err)
}
return GatherAndLint(reg, metricNames...)
}
// GatherAndLint gathers all metrics from the provided Gatherer and checks them
// with the linter in the promlint package. If any metricNames are provided,
// only metrics with those names are checked.
func GatherAndLint(g prometheus.Gatherer, metricNames ...string) ([]promlint.Problem, error) {
got, err := g.Gather()
if err != nil {
return nil, fmt.Errorf("gathering metrics failed: %w", err)
}
if metricNames != nil {
got = filterMetrics(got, metricNames)
}
return promlint.NewWithMetricFamilies(got).Lint()
}

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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promlint
import dto "github.com/prometheus/client_model/go"
// A Problem is an issue detected by a linter.
type Problem struct {
// The name of the metric indicated by this Problem.
Metric string
// A description of the issue for this Problem.
Text string
}
// newProblem is helper function to create a Problem.
func newProblem(mf *dto.MetricFamily, text string) Problem {
return Problem{
Metric: mf.GetName(),
Text: text,
}
}

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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package promlint provides a linter for Prometheus metrics.
package promlint
import (
"errors"
"io"
"sort"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/common/expfmt"
)
// A Linter is a Prometheus metrics linter. It identifies issues with metric
// names, types, and metadata, and reports them to the caller.
type Linter struct {
// The linter will read metrics in the Prometheus text format from r and
// then lint it, _and_ it will lint the metrics provided directly as
// MetricFamily proto messages in mfs. Note, however, that the current
// constructor functions New and NewWithMetricFamilies only ever set one
// of them.
r io.Reader
mfs []*dto.MetricFamily
customValidations []Validation
}
// New creates a new Linter that reads an input stream of Prometheus metrics in
// the Prometheus text exposition format.
func New(r io.Reader) *Linter {
return &Linter{
r: r,
}
}
// NewWithMetricFamilies creates a new Linter that reads from a slice of
// MetricFamily protobuf messages.
func NewWithMetricFamilies(mfs []*dto.MetricFamily) *Linter {
return &Linter{
mfs: mfs,
}
}
// AddCustomValidations adds custom validations to the linter.
func (l *Linter) AddCustomValidations(vs ...Validation) {
if l.customValidations == nil {
l.customValidations = make([]Validation, 0, len(vs))
}
l.customValidations = append(l.customValidations, vs...)
}
// Lint performs a linting pass, returning a slice of Problems indicating any
// issues found in the metrics stream. The slice is sorted by metric name
// and issue description.
func (l *Linter) Lint() ([]Problem, error) {
var problems []Problem
if l.r != nil {
d := expfmt.NewDecoder(l.r, expfmt.NewFormat(expfmt.TypeTextPlain))
mf := &dto.MetricFamily{}
for {
if err := d.Decode(mf); err != nil {
if errors.Is(err, io.EOF) {
break
}
return nil, err
}
problems = append(problems, l.lint(mf)...)
}
}
for _, mf := range l.mfs {
problems = append(problems, l.lint(mf)...)
}
// Ensure deterministic output.
sort.SliceStable(problems, func(i, j int) bool {
if problems[i].Metric == problems[j].Metric {
return problems[i].Text < problems[j].Text
}
return problems[i].Metric < problems[j].Metric
})
return problems, nil
}
// lint is the entry point for linting a single metric.
func (l *Linter) lint(mf *dto.MetricFamily) []Problem {
var problems []Problem
for _, fn := range defaultValidations {
errs := fn(mf)
for _, err := range errs {
problems = append(problems, newProblem(mf, err.Error()))
}
}
if l.customValidations != nil {
for _, fn := range l.customValidations {
errs := fn(mf)
for _, err := range errs {
problems = append(problems, newProblem(mf, err.Error()))
}
}
}
// TODO(mdlayher): lint rules for specific metrics types.
return problems
}

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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package promlint
import (
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/client_golang/prometheus/testutil/promlint/validations"
)
type Validation = func(mf *dto.MetricFamily) []error
var defaultValidations = []Validation{
validations.LintHelp,
validations.LintMetricUnits,
validations.LintCounter,
validations.LintHistogramSummaryReserved,
validations.LintMetricTypeInName,
validations.LintReservedChars,
validations.LintCamelCase,
validations.LintUnitAbbreviations,
validations.LintDuplicateMetric,
}

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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package validations
import (
"errors"
"strings"
dto "github.com/prometheus/client_model/go"
)
// LintCounter detects issues specific to counters, as well as patterns that should
// only be used with counters.
func LintCounter(mf *dto.MetricFamily) []error {
var problems []error
isCounter := mf.GetType() == dto.MetricType_COUNTER
isUntyped := mf.GetType() == dto.MetricType_UNTYPED
hasTotalSuffix := strings.HasSuffix(mf.GetName(), "_total")
switch {
case isCounter && !hasTotalSuffix:
problems = append(problems, errors.New(`counter metrics should have "_total" suffix`))
case !isUntyped && !isCounter && hasTotalSuffix:
problems = append(problems, errors.New(`non-counter metrics should not have "_total" suffix`))
}
return problems
}

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// Copyright 2024 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package validations
import (
"errors"
"reflect"
dto "github.com/prometheus/client_model/go"
)
// LintDuplicateMetric detects duplicate metric.
func LintDuplicateMetric(mf *dto.MetricFamily) []error {
var problems []error
for i, m := range mf.Metric {
for _, k := range mf.Metric[i+1:] {
if reflect.DeepEqual(m.Label, k.Label) {
problems = append(problems, errors.New("metric not unique"))
break
}
}
}
return problems
}

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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package validations
import (
"errors"
"fmt"
"regexp"
"strings"
dto "github.com/prometheus/client_model/go"
)
var camelCase = regexp.MustCompile(`[a-z][A-Z]`)
// LintMetricUnits detects issues with metric unit names.
func LintMetricUnits(mf *dto.MetricFamily) []error {
var problems []error
unit, base, ok := metricUnits(*mf.Name)
if !ok {
// No known units detected.
return nil
}
// Unit is already a base unit.
if unit == base {
return nil
}
problems = append(problems, fmt.Errorf("use base unit %q instead of %q", base, unit))
return problems
}
// LintMetricTypeInName detects when the metric type is included in the metric name.
func LintMetricTypeInName(mf *dto.MetricFamily) []error {
if mf.GetType() == dto.MetricType_UNTYPED {
return nil
}
var problems []error
n := strings.ToLower(mf.GetName())
typename := strings.ToLower(mf.GetType().String())
if strings.Contains(n, "_"+typename+"_") || strings.HasSuffix(n, "_"+typename) {
problems = append(problems, fmt.Errorf(`metric name should not include type '%s'`, typename))
}
return problems
}
// LintReservedChars detects colons in metric names.
func LintReservedChars(mf *dto.MetricFamily) []error {
var problems []error
if strings.Contains(mf.GetName(), ":") {
problems = append(problems, errors.New("metric names should not contain ':'"))
}
return problems
}
// LintCamelCase detects metric names and label names written in camelCase.
func LintCamelCase(mf *dto.MetricFamily) []error {
var problems []error
if camelCase.FindString(mf.GetName()) != "" {
problems = append(problems, errors.New("metric names should be written in 'snake_case' not 'camelCase'"))
}
for _, m := range mf.GetMetric() {
for _, l := range m.GetLabel() {
if camelCase.FindString(l.GetName()) != "" {
problems = append(problems, errors.New("label names should be written in 'snake_case' not 'camelCase'"))
}
}
}
return problems
}
// LintUnitAbbreviations detects abbreviated units in the metric name.
func LintUnitAbbreviations(mf *dto.MetricFamily) []error {
var problems []error
n := strings.ToLower(mf.GetName())
for _, s := range unitAbbreviations {
if strings.Contains(n, "_"+s+"_") || strings.HasSuffix(n, "_"+s) {
problems = append(problems, errors.New("metric names should not contain abbreviated units"))
}
}
return problems
}

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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package validations
import (
"errors"
dto "github.com/prometheus/client_model/go"
)
// LintHelp detects issues related to the help text for a metric.
func LintHelp(mf *dto.MetricFamily) []error {
var problems []error
// Expect all metrics to have help text available.
if mf.Help == nil {
problems = append(problems, errors.New("no help text"))
}
return problems
}

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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package validations
import (
"errors"
"strings"
dto "github.com/prometheus/client_model/go"
)
// LintHistogramSummaryReserved detects when other types of metrics use names or labels
// reserved for use by histograms and/or summaries.
func LintHistogramSummaryReserved(mf *dto.MetricFamily) []error {
// These rules do not apply to untyped metrics.
t := mf.GetType()
if t == dto.MetricType_UNTYPED {
return nil
}
var problems []error
isHistogram := t == dto.MetricType_HISTOGRAM
isSummary := t == dto.MetricType_SUMMARY
n := mf.GetName()
if !isHistogram && strings.HasSuffix(n, "_bucket") {
problems = append(problems, errors.New(`non-histogram metrics should not have "_bucket" suffix`))
}
if !isHistogram && !isSummary && strings.HasSuffix(n, "_count") {
problems = append(problems, errors.New(`non-histogram and non-summary metrics should not have "_count" suffix`))
}
if !isHistogram && !isSummary && strings.HasSuffix(n, "_sum") {
problems = append(problems, errors.New(`non-histogram and non-summary metrics should not have "_sum" suffix`))
}
for _, m := range mf.GetMetric() {
for _, l := range m.GetLabel() {
ln := l.GetName()
if !isHistogram && ln == "le" {
problems = append(problems, errors.New(`non-histogram metrics should not have "le" label`))
}
if !isSummary && ln == "quantile" {
problems = append(problems, errors.New(`non-summary metrics should not have "quantile" label`))
}
}
}
return problems
}

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// Copyright 2020 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package validations
import "strings"
// Units and their possible prefixes recognized by this library. More can be
// added over time as needed.
var (
// map a unit to the appropriate base unit.
units = map[string]string{
// Base units.
"amperes": "amperes",
"bytes": "bytes",
"celsius": "celsius", // Also allow Celsius because it is common in typical Prometheus use cases.
"grams": "grams",
"joules": "joules",
"kelvin": "kelvin", // SI base unit, used in special cases (e.g. color temperature, scientific measurements).
"meters": "meters", // Both American and international spelling permitted.
"metres": "metres",
"seconds": "seconds",
"volts": "volts",
// Non base units.
// Time.
"minutes": "seconds",
"hours": "seconds",
"days": "seconds",
"weeks": "seconds",
// Temperature.
"kelvins": "kelvin",
"fahrenheit": "celsius",
"rankine": "celsius",
// Length.
"inches": "meters",
"yards": "meters",
"miles": "meters",
// Bytes.
"bits": "bytes",
// Energy.
"calories": "joules",
// Mass.
"pounds": "grams",
"ounces": "grams",
}
unitPrefixes = []string{
"pico",
"nano",
"micro",
"milli",
"centi",
"deci",
"deca",
"hecto",
"kilo",
"kibi",
"mega",
"mibi",
"giga",
"gibi",
"tera",
"tebi",
"peta",
"pebi",
}
// Common abbreviations that we'd like to discourage.
unitAbbreviations = []string{
"s",
"ms",
"us",
"ns",
"sec",
"b",
"kb",
"mb",
"gb",
"tb",
"pb",
"m",
"h",
"d",
}
)
// metricUnits attempts to detect known unit types used as part of a metric name,
// e.g. "foo_bytes_total" or "bar_baz_milligrams".
func metricUnits(m string) (unit, base string, ok bool) {
ss := strings.Split(m, "_")
for _, s := range ss {
if base, found := units[s]; found {
return s, base, true
}
for _, p := range unitPrefixes {
if strings.HasPrefix(s, p) {
if base, found := units[s[len(p):]]; found {
return s, base, true
}
}
}
}
return "", "", false
}

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// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package testutil provides helpers to test code using the prometheus package
// of client_golang.
//
// While writing unit tests to verify correct instrumentation of your code, it's
// a common mistake to mostly test the instrumentation library instead of your
// own code. Rather than verifying that a prometheus.Counter's value has changed
// as expected or that it shows up in the exposition after registration, it is
// in general more robust and more faithful to the concept of unit tests to use
// mock implementations of the prometheus.Counter and prometheus.Registerer
// interfaces that simply assert that the Add or Register methods have been
// called with the expected arguments. However, this might be overkill in simple
// scenarios. The ToFloat64 function is provided for simple inspection of a
// single-value metric, but it has to be used with caution.
//
// End-to-end tests to verify all or larger parts of the metrics exposition can
// be implemented with the CollectAndCompare or GatherAndCompare functions. The
// most appropriate use is not so much testing instrumentation of your code, but
// testing custom prometheus.Collector implementations and in particular whole
// exporters, i.e. programs that retrieve telemetry data from a 3rd party source
// and convert it into Prometheus metrics.
//
// In a similar pattern, CollectAndLint and GatherAndLint can be used to detect
// metrics that have issues with their name, type, or metadata without being
// necessarily invalid, e.g. a counter with a name missing the “_total” suffix.
package testutil
import (
"bytes"
"errors"
"fmt"
"io"
"net/http"
"github.com/kylelemons/godebug/diff"
dto "github.com/prometheus/client_model/go"
"github.com/prometheus/common/expfmt"
"github.com/prometheus/common/model"
"google.golang.org/protobuf/proto"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/internal"
)
// ToFloat64 collects all Metrics from the provided Collector. It expects that
// this results in exactly one Metric being collected, which must be a Gauge,
// Counter, or Untyped. In all other cases, ToFloat64 panics. ToFloat64 returns
// the value of the collected Metric.
//
// The Collector provided is typically a simple instance of Gauge or Counter, or
// less commonly a GaugeVec or CounterVec with exactly one element. But any
// Collector fulfilling the prerequisites described above will do.
//
// Use this function with caution. It is computationally very expensive and thus
// not suited at all to read values from Metrics in regular code. This is really
// only for testing purposes, and even for testing, other approaches are often
// more appropriate (see this package's documentation).
//
// A clear anti-pattern would be to use a metric type from the prometheus
// package to track values that are also needed for something else than the
// exposition of Prometheus metrics. For example, you would like to track the
// number of items in a queue because your code should reject queuing further
// items if a certain limit is reached. It is tempting to track the number of
// items in a prometheus.Gauge, as it is then easily available as a metric for
// exposition, too. However, then you would need to call ToFloat64 in your
// regular code, potentially quite often. The recommended way is to track the
// number of items conventionally (in the way you would have done it without
// considering Prometheus metrics) and then expose the number with a
// prometheus.GaugeFunc.
func ToFloat64(c prometheus.Collector) float64 {
var (
m prometheus.Metric
mCount int
mChan = make(chan prometheus.Metric)
done = make(chan struct{})
)
go func() {
for m = range mChan {
mCount++
}
close(done)
}()
c.Collect(mChan)
close(mChan)
<-done
if mCount != 1 {
panic(fmt.Errorf("collected %d metrics instead of exactly 1", mCount))
}
pb := &dto.Metric{}
if err := m.Write(pb); err != nil {
panic(fmt.Errorf("error happened while collecting metrics: %w", err))
}
if pb.Gauge != nil {
return pb.Gauge.GetValue()
}
if pb.Counter != nil {
return pb.Counter.GetValue()
}
if pb.Untyped != nil {
return pb.Untyped.GetValue()
}
panic(fmt.Errorf("collected a non-gauge/counter/untyped metric: %s", pb))
}
// CollectAndCount registers the provided Collector with a newly created
// pedantic Registry. It then calls GatherAndCount with that Registry and with
// the provided metricNames. In the unlikely case that the registration or the
// gathering fails, this function panics. (This is inconsistent with the other
// CollectAnd… functions in this package and has historical reasons. Changing
// the function signature would be a breaking change and will therefore only
// happen with the next major version bump.)
func CollectAndCount(c prometheus.Collector, metricNames ...string) int {
reg := prometheus.NewPedanticRegistry()
if err := reg.Register(c); err != nil {
panic(fmt.Errorf("registering collector failed: %w", err))
}
result, err := GatherAndCount(reg, metricNames...)
if err != nil {
panic(err)
}
return result
}
// GatherAndCount gathers all metrics from the provided Gatherer and counts
// them. It returns the number of metric children in all gathered metric
// families together. If any metricNames are provided, only metrics with those
// names are counted.
func GatherAndCount(g prometheus.Gatherer, metricNames ...string) (int, error) {
got, err := g.Gather()
if err != nil {
return 0, fmt.Errorf("gathering metrics failed: %w", err)
}
if metricNames != nil {
got = filterMetrics(got, metricNames)
}
result := 0
for _, mf := range got {
result += len(mf.GetMetric())
}
return result, nil
}
// ScrapeAndCompare calls a remote exporter's endpoint which is expected to return some metrics in
// plain text format. Then it compares it with the results that the `expected` would return.
// If the `metricNames` is not empty it would filter the comparison only to the given metric names.
//
// NOTE: Be mindful of accidental discrepancies between expected and metricNames; metricNames filter
// both expected and scraped metrics. See https://github.com/prometheus/client_golang/issues/1351.
func ScrapeAndCompare(url string, expected io.Reader, metricNames ...string) error {
resp, err := http.Get(url)
if err != nil {
return fmt.Errorf("scraping metrics failed: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return fmt.Errorf("the scraping target returned a status code other than 200: %d",
resp.StatusCode)
}
scraped, err := convertReaderToMetricFamily(resp.Body)
if err != nil {
return err
}
wanted, err := convertReaderToMetricFamily(expected)
if err != nil {
return err
}
return compareMetricFamilies(scraped, wanted, metricNames...)
}
// CollectAndCompare collects the metrics identified by `metricNames` and compares them in the Prometheus text
// exposition format to the data read from expected.
//
// NOTE: Be mindful of accidental discrepancies between expected and metricNames; metricNames filter
// both expected and collected metrics. See https://github.com/prometheus/client_golang/issues/1351.
func CollectAndCompare(c prometheus.Collector, expected io.Reader, metricNames ...string) error {
reg := prometheus.NewPedanticRegistry()
if err := reg.Register(c); err != nil {
return fmt.Errorf("registering collector failed: %w", err)
}
return GatherAndCompare(reg, expected, metricNames...)
}
// GatherAndCompare gathers all metrics from the provided Gatherer and compares
// it to an expected output read from the provided Reader in the Prometheus text
// exposition format. If any metricNames are provided, only metrics with those
// names are compared.
//
// NOTE: Be mindful of accidental discrepancies between expected and metricNames; metricNames filter
// both expected and gathered metrics. See https://github.com/prometheus/client_golang/issues/1351.
func GatherAndCompare(g prometheus.Gatherer, expected io.Reader, metricNames ...string) error {
return TransactionalGatherAndCompare(prometheus.ToTransactionalGatherer(g), expected, metricNames...)
}
// TransactionalGatherAndCompare gathers all metrics from the provided Gatherer and compares
// it to an expected output read from the provided Reader in the Prometheus text
// exposition format. If any metricNames are provided, only metrics with those
// names are compared.
//
// NOTE: Be mindful of accidental discrepancies between expected and metricNames; metricNames filter
// both expected and gathered metrics. See https://github.com/prometheus/client_golang/issues/1351.
func TransactionalGatherAndCompare(g prometheus.TransactionalGatherer, expected io.Reader, metricNames ...string) error {
got, done, err := g.Gather()
defer done()
if err != nil {
return fmt.Errorf("gathering metrics failed: %w", err)
}
wanted, err := convertReaderToMetricFamily(expected)
if err != nil {
return err
}
return compareMetricFamilies(got, wanted, metricNames...)
}
// CollectAndFormat collects the metrics identified by `metricNames` and returns them in the given format.
func CollectAndFormat(c prometheus.Collector, format expfmt.FormatType, metricNames ...string) ([]byte, error) {
reg := prometheus.NewPedanticRegistry()
if err := reg.Register(c); err != nil {
return nil, fmt.Errorf("registering collector failed: %w", err)
}
gotFiltered, err := reg.Gather()
if err != nil {
return nil, fmt.Errorf("gathering metrics failed: %w", err)
}
gotFiltered = filterMetrics(gotFiltered, metricNames)
var gotFormatted bytes.Buffer
enc := expfmt.NewEncoder(&gotFormatted, expfmt.NewFormat(format))
for _, mf := range gotFiltered {
if err := enc.Encode(mf); err != nil {
return nil, fmt.Errorf("encoding gathered metrics failed: %w", err)
}
}
return gotFormatted.Bytes(), nil
}
// convertReaderToMetricFamily would read from a io.Reader object and convert it to a slice of
// dto.MetricFamily.
func convertReaderToMetricFamily(reader io.Reader) ([]*dto.MetricFamily, error) {
var tp expfmt.TextParser
notNormalized, err := tp.TextToMetricFamilies(reader)
if err != nil {
return nil, fmt.Errorf("converting reader to metric families failed: %w", err)
}
// The text protocol handles empty help fields inconsistently. When
// encoding, any non-nil value, include the empty string, produces a
// "# HELP" line. But when decoding, the help field is only set to a
// non-nil value if the "# HELP" line contains a non-empty value.
//
// Because metrics in a registry always have non-nil help fields, populate
// any nil help fields in the parsed metrics with the empty string so that
// when we compare text encodings, the results are consistent.
for _, metric := range notNormalized {
if metric.Help == nil {
metric.Help = proto.String("")
}
}
return internal.NormalizeMetricFamilies(notNormalized), nil
}
// compareMetricFamilies would compare 2 slices of metric families, and optionally filters both of
// them to the `metricNames` provided.
func compareMetricFamilies(got, expected []*dto.MetricFamily, metricNames ...string) error {
if metricNames != nil {
got = filterMetrics(got, metricNames)
expected = filterMetrics(expected, metricNames)
}
return compare(got, expected)
}
// compare encodes both provided slices of metric families into the text format,
// compares their string message, and returns an error if they do not match.
// The error contains the encoded text of both the desired and the actual
// result.
func compare(got, want []*dto.MetricFamily) error {
var gotBuf, wantBuf bytes.Buffer
enc := expfmt.NewEncoder(&gotBuf, expfmt.NewFormat(expfmt.TypeTextPlain).WithEscapingScheme(model.NoEscaping))
for _, mf := range got {
if err := enc.Encode(mf); err != nil {
return fmt.Errorf("encoding gathered metrics failed: %w", err)
}
}
enc = expfmt.NewEncoder(&wantBuf, expfmt.NewFormat(expfmt.TypeTextPlain).WithEscapingScheme(model.NoEscaping))
for _, mf := range want {
if err := enc.Encode(mf); err != nil {
return fmt.Errorf("encoding expected metrics failed: %w", err)
}
}
if diffErr := diff.Diff(gotBuf.String(), wantBuf.String()); diffErr != "" {
return errors.New(diffErr)
}
return nil
}
func filterMetrics(metrics []*dto.MetricFamily, names []string) []*dto.MetricFamily {
var filtered []*dto.MetricFamily
for _, m := range metrics {
for _, name := range names {
if m.GetName() == name {
filtered = append(filtered, m)
break
}
}
}
return filtered
}

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// Copyright 2016 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import "time"
// Timer is a helper type to time functions. Use NewTimer to create new
// instances.
type Timer struct {
begin time.Time
observer Observer
}
// NewTimer creates a new Timer. The provided Observer is used to observe a
// duration in seconds. If the Observer implements ExemplarObserver, passing exemplar
// later on will be also supported.
// Timer is usually used to time a function call in the
// following way:
//
// func TimeMe() {
// timer := NewTimer(myHistogram)
// defer timer.ObserveDuration()
// // Do actual work.
// }
//
// or
//
// func TimeMeWithExemplar() {
// timer := NewTimer(myHistogram)
// defer timer.ObserveDurationWithExemplar(exemplar)
// // Do actual work.
// }
func NewTimer(o Observer) *Timer {
return &Timer{
begin: time.Now(),
observer: o,
}
}
// ObserveDuration records the duration passed since the Timer was created with
// NewTimer. It calls the Observe method of the Observer provided during
// construction with the duration in seconds as an argument. The observed
// duration is also returned. ObserveDuration is usually called with a defer
// statement.
//
// Note that this method is only guaranteed to never observe negative durations
// if used with Go1.9+.
func (t *Timer) ObserveDuration() time.Duration {
d := time.Since(t.begin)
if t.observer != nil {
t.observer.Observe(d.Seconds())
}
return d
}
// ObserveDurationWithExemplar is like ObserveDuration, but it will also
// observe exemplar with the duration unless exemplar is nil or provided Observer can't
// be casted to ExemplarObserver.
func (t *Timer) ObserveDurationWithExemplar(exemplar Labels) time.Duration {
d := time.Since(t.begin)
eo, ok := t.observer.(ExemplarObserver)
if ok && exemplar != nil {
eo.ObserveWithExemplar(d.Seconds(), exemplar)
return d
}
if t.observer != nil {
t.observer.Observe(d.Seconds())
}
return d
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
// UntypedOpts is an alias for Opts. See there for doc comments.
type UntypedOpts Opts
// UntypedFunc works like GaugeFunc but the collected metric is of type
// "Untyped". UntypedFunc is useful to mirror an external metric of unknown
// type.
//
// To create UntypedFunc instances, use NewUntypedFunc.
type UntypedFunc interface {
Metric
Collector
}
// NewUntypedFunc creates a new UntypedFunc based on the provided
// UntypedOpts. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where an UntypedFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe.
func NewUntypedFunc(opts UntypedOpts, function func() float64) UntypedFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
nil,
opts.ConstLabels,
), UntypedValue, function)
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"errors"
"fmt"
"sort"
"time"
"unicode/utf8"
"github.com/prometheus/client_golang/prometheus/internal"
dto "github.com/prometheus/client_model/go"
"google.golang.org/protobuf/proto"
"google.golang.org/protobuf/types/known/timestamppb"
)
// ValueType is an enumeration of metric types that represent a simple value.
type ValueType int
// Possible values for the ValueType enum. Use UntypedValue to mark a metric
// with an unknown type.
const (
_ ValueType = iota
CounterValue
GaugeValue
UntypedValue
)
var (
CounterMetricTypePtr = func() *dto.MetricType { d := dto.MetricType_COUNTER; return &d }()
GaugeMetricTypePtr = func() *dto.MetricType { d := dto.MetricType_GAUGE; return &d }()
UntypedMetricTypePtr = func() *dto.MetricType { d := dto.MetricType_UNTYPED; return &d }()
)
func (v ValueType) ToDTO() *dto.MetricType {
switch v {
case CounterValue:
return CounterMetricTypePtr
case GaugeValue:
return GaugeMetricTypePtr
default:
return UntypedMetricTypePtr
}
}
// valueFunc is a generic metric for simple values retrieved on collect time
// from a function. It implements Metric and Collector. Its effective type is
// determined by ValueType. This is a low-level building block used by the
// library to back the implementations of CounterFunc, GaugeFunc, and
// UntypedFunc.
type valueFunc struct {
selfCollector
desc *Desc
valType ValueType
function func() float64
labelPairs []*dto.LabelPair
}
// newValueFunc returns a newly allocated valueFunc with the given Desc and
// ValueType. The value reported is determined by calling the given function
// from within the Write method. Take into account that metric collection may
// happen concurrently. If that results in concurrent calls to Write, like in
// the case where a valueFunc is directly registered with Prometheus, the
// provided function must be concurrency-safe.
func newValueFunc(desc *Desc, valueType ValueType, function func() float64) *valueFunc {
result := &valueFunc{
desc: desc,
valType: valueType,
function: function,
labelPairs: MakeLabelPairs(desc, nil),
}
result.init(result)
return result
}
func (v *valueFunc) Desc() *Desc {
return v.desc
}
func (v *valueFunc) Write(out *dto.Metric) error {
return populateMetric(v.valType, v.function(), v.labelPairs, nil, out, nil)
}
// NewConstMetric returns a metric with one fixed value that cannot be
// changed. Users of this package will not have much use for it in regular
// operations. However, when implementing custom Collectors, it is useful as a
// throw-away metric that is generated on the fly to send it to Prometheus in
// the Collect method. NewConstMetric returns an error if the length of
// labelValues is not consistent with the variable labels in Desc or if Desc is
// invalid.
func NewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) (Metric, error) {
if desc.err != nil {
return nil, desc.err
}
if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
return nil, err
}
metric := &dto.Metric{}
if err := populateMetric(valueType, value, MakeLabelPairs(desc, labelValues), nil, metric, nil); err != nil {
return nil, err
}
return &constMetric{
desc: desc,
metric: metric,
}, nil
}
// MustNewConstMetric is a version of NewConstMetric that panics where
// NewConstMetric would have returned an error.
func MustNewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) Metric {
m, err := NewConstMetric(desc, valueType, value, labelValues...)
if err != nil {
panic(err)
}
return m
}
// NewConstMetricWithCreatedTimestamp does the same thing as NewConstMetric, but generates Counters
// with created timestamp set and returns an error for other metric types.
func NewConstMetricWithCreatedTimestamp(desc *Desc, valueType ValueType, value float64, ct time.Time, labelValues ...string) (Metric, error) {
if desc.err != nil {
return nil, desc.err
}
if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
return nil, err
}
switch valueType {
case CounterValue:
break
default:
return nil, errors.New("created timestamps are only supported for counters")
}
metric := &dto.Metric{}
if err := populateMetric(valueType, value, MakeLabelPairs(desc, labelValues), nil, metric, timestamppb.New(ct)); err != nil {
return nil, err
}
return &constMetric{
desc: desc,
metric: metric,
}, nil
}
// MustNewConstMetricWithCreatedTimestamp is a version of NewConstMetricWithCreatedTimestamp that panics where
// NewConstMetricWithCreatedTimestamp would have returned an error.
func MustNewConstMetricWithCreatedTimestamp(desc *Desc, valueType ValueType, value float64, ct time.Time, labelValues ...string) Metric {
m, err := NewConstMetricWithCreatedTimestamp(desc, valueType, value, ct, labelValues...)
if err != nil {
panic(err)
}
return m
}
type constMetric struct {
desc *Desc
metric *dto.Metric
}
func (m *constMetric) Desc() *Desc {
return m.desc
}
func (m *constMetric) Write(out *dto.Metric) error {
out.Label = m.metric.Label
out.Counter = m.metric.Counter
out.Gauge = m.metric.Gauge
out.Untyped = m.metric.Untyped
return nil
}
func populateMetric(
t ValueType,
v float64,
labelPairs []*dto.LabelPair,
e *dto.Exemplar,
m *dto.Metric,
ct *timestamppb.Timestamp,
) error {
m.Label = labelPairs
switch t {
case CounterValue:
m.Counter = &dto.Counter{Value: proto.Float64(v), Exemplar: e, CreatedTimestamp: ct}
case GaugeValue:
m.Gauge = &dto.Gauge{Value: proto.Float64(v)}
case UntypedValue:
m.Untyped = &dto.Untyped{Value: proto.Float64(v)}
default:
return fmt.Errorf("encountered unknown type %v", t)
}
return nil
}
// MakeLabelPairs is a helper function to create protobuf LabelPairs from the
// variable and constant labels in the provided Desc. The values for the
// variable labels are defined by the labelValues slice, which must be in the
// same order as the corresponding variable labels in the Desc.
//
// This function is only needed for custom Metric implementations. See MetricVec
// example.
func MakeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair {
totalLen := len(desc.variableLabels.names) + len(desc.constLabelPairs)
if totalLen == 0 {
// Super fast path.
return nil
}
if len(desc.variableLabels.names) == 0 {
// Moderately fast path.
return desc.constLabelPairs
}
labelPairs := make([]*dto.LabelPair, 0, totalLen)
for i, l := range desc.variableLabels.names {
labelPairs = append(labelPairs, &dto.LabelPair{
Name: proto.String(l),
Value: proto.String(labelValues[i]),
})
}
labelPairs = append(labelPairs, desc.constLabelPairs...)
sort.Sort(internal.LabelPairSorter(labelPairs))
return labelPairs
}
// ExemplarMaxRunes is the max total number of runes allowed in exemplar labels.
const ExemplarMaxRunes = 128
// newExemplar creates a new dto.Exemplar from the provided values. An error is
// returned if any of the label names or values are invalid or if the total
// number of runes in the label names and values exceeds ExemplarMaxRunes.
func newExemplar(value float64, ts time.Time, l Labels) (*dto.Exemplar, error) {
e := &dto.Exemplar{}
e.Value = proto.Float64(value)
tsProto := timestamppb.New(ts)
if err := tsProto.CheckValid(); err != nil {
return nil, err
}
e.Timestamp = tsProto
labelPairs := make([]*dto.LabelPair, 0, len(l))
var runes int
for name, value := range l {
if !checkLabelName(name) {
return nil, fmt.Errorf("exemplar label name %q is invalid", name)
}
runes += utf8.RuneCountInString(name)
if !utf8.ValidString(value) {
return nil, fmt.Errorf("exemplar label value %q is not valid UTF-8", value)
}
runes += utf8.RuneCountInString(value)
labelPairs = append(labelPairs, &dto.LabelPair{
Name: proto.String(name),
Value: proto.String(value),
})
}
if runes > ExemplarMaxRunes {
return nil, fmt.Errorf("exemplar labels have %d runes, exceeding the limit of %d", runes, ExemplarMaxRunes)
}
e.Label = labelPairs
return e, nil
}

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// Copyright 2014 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"sync"
"github.com/prometheus/common/model"
)
// MetricVec is a Collector to bundle metrics of the same name that differ in
// their label values. MetricVec is not used directly but as a building block
// for implementations of vectors of a given metric type, like GaugeVec,
// CounterVec, SummaryVec, and HistogramVec. It is exported so that it can be
// used for custom Metric implementations.
//
// To create a FooVec for custom Metric Foo, embed a pointer to MetricVec in
// FooVec and initialize it with NewMetricVec. Implement wrappers for
// GetMetricWithLabelValues and GetMetricWith that return (Foo, error) rather
// than (Metric, error). Similarly, create a wrapper for CurryWith that returns
// (*FooVec, error) rather than (*MetricVec, error). It is recommended to also
// add the convenience methods WithLabelValues, With, and MustCurryWith, which
// panic instead of returning errors. See also the MetricVec example.
type MetricVec struct {
*metricMap
curry []curriedLabelValue
// hashAdd and hashAddByte can be replaced for testing collision handling.
hashAdd func(h uint64, s string) uint64
hashAddByte func(h uint64, b byte) uint64
}
// NewMetricVec returns an initialized metricVec.
func NewMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec {
return &MetricVec{
metricMap: &metricMap{
metrics: map[uint64][]metricWithLabelValues{},
desc: desc,
newMetric: newMetric,
},
hashAdd: hashAdd,
hashAddByte: hashAddByte,
}
}
// DeleteLabelValues removes the metric where the variable labels are the same
// as those passed in as labels (same order as the VariableLabels in Desc). It
// returns true if a metric was deleted.
//
// It is not an error if the number of label values is not the same as the
// number of VariableLabels in Desc. However, such inconsistent label count can
// never match an actual metric, so the method will always return false in that
// case.
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider Delete(Labels) as an
// alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
// See also the CounterVec example.
func (m *MetricVec) DeleteLabelValues(lvs ...string) bool {
lvs = constrainLabelValues(m.desc, lvs, m.curry)
h, err := m.hashLabelValues(lvs)
if err != nil {
return false
}
return m.metricMap.deleteByHashWithLabelValues(h, lvs, m.curry)
}
// Delete deletes the metric where the variable labels are the same as those
// passed in as labels. It returns true if a metric was deleted.
//
// It is not an error if the number and names of the Labels are inconsistent
// with those of the VariableLabels in Desc. However, such inconsistent Labels
// can never match an actual metric, so the method will always return false in
// that case.
//
// This method is used for the same purpose as DeleteLabelValues(...string). See
// there for pros and cons of the two methods.
func (m *MetricVec) Delete(labels Labels) bool {
labels, closer := constrainLabels(m.desc, labels)
defer closer()
h, err := m.hashLabels(labels)
if err != nil {
return false
}
return m.metricMap.deleteByHashWithLabels(h, labels, m.curry)
}
// DeletePartialMatch deletes all metrics where the variable labels contain all of those
// passed in as labels. The order of the labels does not matter.
// It returns the number of metrics deleted.
//
// Note that curried labels will never be matched if deleting from the curried vector.
// To match curried labels with DeletePartialMatch, it must be called on the base vector.
func (m *MetricVec) DeletePartialMatch(labels Labels) int {
labels, closer := constrainLabels(m.desc, labels)
defer closer()
return m.metricMap.deleteByLabels(labels, m.curry)
}
// Without explicit forwarding of Describe, Collect, Reset, those methods won't
// show up in GoDoc.
// Describe implements Collector.
func (m *MetricVec) Describe(ch chan<- *Desc) { m.metricMap.Describe(ch) }
// Collect implements Collector.
func (m *MetricVec) Collect(ch chan<- Metric) { m.metricMap.Collect(ch) }
// Reset deletes all metrics in this vector.
func (m *MetricVec) Reset() { m.metricMap.Reset() }
// CurryWith returns a vector curried with the provided labels, i.e. the
// returned vector has those labels pre-set for all labeled operations performed
// on it. The cardinality of the curried vector is reduced accordingly. The
// order of the remaining labels stays the same (just with the curried labels
// taken out of the sequence which is relevant for the
// (GetMetric)WithLabelValues methods). It is possible to curry a curried
// vector, but only with labels not yet used for currying before.
//
// The metrics contained in the MetricVec are shared between the curried and
// uncurried vectors. They are just accessed differently. Curried and uncurried
// vectors behave identically in terms of collection. Only one must be
// registered with a given registry (usually the uncurried version). The Reset
// method deletes all metrics, even if called on a curried vector.
//
// Note that CurryWith is usually not called directly but through a wrapper
// around MetricVec, implementing a vector for a specific Metric
// implementation, for example GaugeVec.
func (m *MetricVec) CurryWith(labels Labels) (*MetricVec, error) {
var (
newCurry []curriedLabelValue
oldCurry = m.curry
iCurry int
)
for i, labelName := range m.desc.variableLabels.names {
val, ok := labels[labelName]
if iCurry < len(oldCurry) && oldCurry[iCurry].index == i {
if ok {
return nil, fmt.Errorf("label name %q is already curried", labelName)
}
newCurry = append(newCurry, oldCurry[iCurry])
iCurry++
} else {
if !ok {
continue // Label stays uncurried.
}
newCurry = append(newCurry, curriedLabelValue{
i,
m.desc.variableLabels.constrain(labelName, val),
})
}
}
if l := len(oldCurry) + len(labels) - len(newCurry); l > 0 {
return nil, fmt.Errorf("%d unknown label(s) found during currying", l)
}
return &MetricVec{
metricMap: m.metricMap,
curry: newCurry,
hashAdd: m.hashAdd,
hashAddByte: m.hashAddByte,
}, nil
}
// GetMetricWithLabelValues returns the Metric for the given slice of label
// values (same order as the variable labels in Desc). If that combination of
// label values is accessed for the first time, a new Metric is created (by
// calling the newMetric function provided during construction of the
// MetricVec).
//
// It is possible to call this method without using the returned Metric to only
// create the new Metric but leave it in its initial state.
//
// Keeping the Metric for later use is possible (and should be considered if
// performance is critical), but keep in mind that Reset, DeleteLabelValues and
// Delete can be used to delete the Metric from the MetricVec. In that case, the
// Metric will still exist, but it will not be exported anymore, even if a
// Metric with the same label values is created later.
//
// An error is returned if the number of label values is not the same as the
// number of variable labels in Desc (minus any curried labels).
//
// Note that for more than one label value, this method is prone to mistakes
// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
// an alternative to avoid that type of mistake. For higher label numbers, the
// latter has a much more readable (albeit more verbose) syntax, but it comes
// with a performance overhead (for creating and processing the Labels map).
//
// Note that GetMetricWithLabelValues is usually not called directly but through
// a wrapper around MetricVec, implementing a vector for a specific Metric
// implementation, for example GaugeVec.
func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) {
lvs = constrainLabelValues(m.desc, lvs, m.curry)
h, err := m.hashLabelValues(lvs)
if err != nil {
return nil, err
}
return m.metricMap.getOrCreateMetricWithLabelValues(h, lvs, m.curry), nil
}
// GetMetricWith returns the Metric for the given Labels map (the label names
// must match those of the variable labels in Desc). If that label map is
// accessed for the first time, a new Metric is created. Implications of
// creating a Metric without using it and keeping the Metric for later use
// are the same as for GetMetricWithLabelValues.
//
// An error is returned if the number and names of the Labels are inconsistent
// with those of the variable labels in Desc (minus any curried labels).
//
// This method is used for the same purpose as
// GetMetricWithLabelValues(...string). See there for pros and cons of the two
// methods.
//
// Note that GetMetricWith is usually not called directly but through a wrapper
// around MetricVec, implementing a vector for a specific Metric implementation,
// for example GaugeVec.
func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) {
labels, closer := constrainLabels(m.desc, labels)
defer closer()
h, err := m.hashLabels(labels)
if err != nil {
return nil, err
}
return m.metricMap.getOrCreateMetricWithLabels(h, labels, m.curry), nil
}
func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) {
if err := validateLabelValues(vals, len(m.desc.variableLabels.names)-len(m.curry)); err != nil {
return 0, err
}
var (
h = hashNew()
curry = m.curry
iVals, iCurry int
)
for i := 0; i < len(m.desc.variableLabels.names); i++ {
if iCurry < len(curry) && curry[iCurry].index == i {
h = m.hashAdd(h, curry[iCurry].value)
iCurry++
} else {
h = m.hashAdd(h, vals[iVals])
iVals++
}
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
func (m *MetricVec) hashLabels(labels Labels) (uint64, error) {
if err := validateValuesInLabels(labels, len(m.desc.variableLabels.names)-len(m.curry)); err != nil {
return 0, err
}
var (
h = hashNew()
curry = m.curry
iCurry int
)
for i, labelName := range m.desc.variableLabels.names {
val, ok := labels[labelName]
if iCurry < len(curry) && curry[iCurry].index == i {
if ok {
return 0, fmt.Errorf("label name %q is already curried", labelName)
}
h = m.hashAdd(h, curry[iCurry].value)
iCurry++
} else {
if !ok {
return 0, fmt.Errorf("label name %q missing in label map", labelName)
}
h = m.hashAdd(h, val)
}
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
// metricWithLabelValues provides the metric and its label values for
// disambiguation on hash collision.
type metricWithLabelValues struct {
values []string
metric Metric
}
// curriedLabelValue sets the curried value for a label at the given index.
type curriedLabelValue struct {
index int
value string
}
// metricMap is a helper for metricVec and shared between differently curried
// metricVecs.
type metricMap struct {
mtx sync.RWMutex // Protects metrics.
metrics map[uint64][]metricWithLabelValues
desc *Desc
newMetric func(labelValues ...string) Metric
}
// Describe implements Collector. It will send exactly one Desc to the provided
// channel.
func (m *metricMap) Describe(ch chan<- *Desc) {
ch <- m.desc
}
// Collect implements Collector.
func (m *metricMap) Collect(ch chan<- Metric) {
m.mtx.RLock()
defer m.mtx.RUnlock()
for _, metrics := range m.metrics {
for _, metric := range metrics {
ch <- metric.metric
}
}
}
// Reset deletes all metrics in this vector.
func (m *metricMap) Reset() {
m.mtx.Lock()
defer m.mtx.Unlock()
for h := range m.metrics {
delete(m.metrics, h)
}
}
// deleteByHashWithLabelValues removes the metric from the hash bucket h. If
// there are multiple matches in the bucket, use lvs to select a metric and
// remove only that metric.
func (m *metricMap) deleteByHashWithLabelValues(
h uint64, lvs []string, curry []curriedLabelValue,
) bool {
m.mtx.Lock()
defer m.mtx.Unlock()
metrics, ok := m.metrics[h]
if !ok {
return false
}
i := findMetricWithLabelValues(metrics, lvs, curry)
if i >= len(metrics) {
return false
}
if len(metrics) > 1 {
old := metrics
m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
old[len(old)-1] = metricWithLabelValues{}
} else {
delete(m.metrics, h)
}
return true
}
// deleteByHashWithLabels removes the metric from the hash bucket h. If there
// are multiple matches in the bucket, use lvs to select a metric and remove
// only that metric.
func (m *metricMap) deleteByHashWithLabels(
h uint64, labels Labels, curry []curriedLabelValue,
) bool {
m.mtx.Lock()
defer m.mtx.Unlock()
metrics, ok := m.metrics[h]
if !ok {
return false
}
i := findMetricWithLabels(m.desc, metrics, labels, curry)
if i >= len(metrics) {
return false
}
if len(metrics) > 1 {
old := metrics
m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
old[len(old)-1] = metricWithLabelValues{}
} else {
delete(m.metrics, h)
}
return true
}
// deleteByLabels deletes a metric if the given labels are present in the metric.
func (m *metricMap) deleteByLabels(labels Labels, curry []curriedLabelValue) int {
m.mtx.Lock()
defer m.mtx.Unlock()
var numDeleted int
for h, metrics := range m.metrics {
i := findMetricWithPartialLabels(m.desc, metrics, labels, curry)
if i >= len(metrics) {
// Didn't find matching labels in this metric slice.
continue
}
delete(m.metrics, h)
numDeleted++
}
return numDeleted
}
// findMetricWithPartialLabel returns the index of the matching metric or
// len(metrics) if not found.
func findMetricWithPartialLabels(
desc *Desc, metrics []metricWithLabelValues, labels Labels, curry []curriedLabelValue,
) int {
for i, metric := range metrics {
if matchPartialLabels(desc, metric.values, labels, curry) {
return i
}
}
return len(metrics)
}
// indexOf searches the given slice of strings for the target string and returns
// the index or len(items) as well as a boolean whether the search succeeded.
func indexOf(target string, items []string) (int, bool) {
for i, l := range items {
if l == target {
return i, true
}
}
return len(items), false
}
// valueMatchesVariableOrCurriedValue determines if a value was previously curried,
// and returns whether it matches either the "base" value or the curried value accordingly.
// It also indicates whether the match is against a curried or uncurried value.
func valueMatchesVariableOrCurriedValue(targetValue string, index int, values []string, curry []curriedLabelValue) (bool, bool) {
for _, curriedValue := range curry {
if curriedValue.index == index {
// This label was curried. See if the curried value matches our target.
return curriedValue.value == targetValue, true
}
}
// This label was not curried. See if the current value matches our target label.
return values[index] == targetValue, false
}
// matchPartialLabels searches the current metric and returns whether all of the target label:value pairs are present.
func matchPartialLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool {
for l, v := range labels {
// Check if the target label exists in our metrics and get the index.
varLabelIndex, validLabel := indexOf(l, desc.variableLabels.names)
if validLabel {
// Check the value of that label against the target value.
// We don't consider curried values in partial matches.
matches, curried := valueMatchesVariableOrCurriedValue(v, varLabelIndex, values, curry)
if matches && !curried {
continue
}
}
return false
}
return true
}
// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
// or creates it and returns the new one.
//
// This function holds the mutex.
func (m *metricMap) getOrCreateMetricWithLabelValues(
hash uint64, lvs []string, curry []curriedLabelValue,
) Metric {
m.mtx.RLock()
metric, ok := m.getMetricWithHashAndLabelValues(hash, lvs, curry)
m.mtx.RUnlock()
if ok {
return metric
}
m.mtx.Lock()
defer m.mtx.Unlock()
metric, ok = m.getMetricWithHashAndLabelValues(hash, lvs, curry)
if !ok {
inlinedLVs := inlineLabelValues(lvs, curry)
metric = m.newMetric(inlinedLVs...)
m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: inlinedLVs, metric: metric})
}
return metric
}
// getOrCreateMetricWithLabels retrieves the metric by hash and label value
// or creates it and returns the new one.
//
// This function holds the mutex.
func (m *metricMap) getOrCreateMetricWithLabels(
hash uint64, labels Labels, curry []curriedLabelValue,
) Metric {
m.mtx.RLock()
metric, ok := m.getMetricWithHashAndLabels(hash, labels, curry)
m.mtx.RUnlock()
if ok {
return metric
}
m.mtx.Lock()
defer m.mtx.Unlock()
metric, ok = m.getMetricWithHashAndLabels(hash, labels, curry)
if !ok {
lvs := extractLabelValues(m.desc, labels, curry)
metric = m.newMetric(lvs...)
m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: lvs, metric: metric})
}
return metric
}
// getMetricWithHashAndLabelValues gets a metric while handling possible
// collisions in the hash space. Must be called while holding the read mutex.
func (m *metricMap) getMetricWithHashAndLabelValues(
h uint64, lvs []string, curry []curriedLabelValue,
) (Metric, bool) {
metrics, ok := m.metrics[h]
if ok {
if i := findMetricWithLabelValues(metrics, lvs, curry); i < len(metrics) {
return metrics[i].metric, true
}
}
return nil, false
}
// getMetricWithHashAndLabels gets a metric while handling possible collisions in
// the hash space. Must be called while holding read mutex.
func (m *metricMap) getMetricWithHashAndLabels(
h uint64, labels Labels, curry []curriedLabelValue,
) (Metric, bool) {
metrics, ok := m.metrics[h]
if ok {
if i := findMetricWithLabels(m.desc, metrics, labels, curry); i < len(metrics) {
return metrics[i].metric, true
}
}
return nil, false
}
// findMetricWithLabelValues returns the index of the matching metric or
// len(metrics) if not found.
func findMetricWithLabelValues(
metrics []metricWithLabelValues, lvs []string, curry []curriedLabelValue,
) int {
for i, metric := range metrics {
if matchLabelValues(metric.values, lvs, curry) {
return i
}
}
return len(metrics)
}
// findMetricWithLabels returns the index of the matching metric or len(metrics)
// if not found.
func findMetricWithLabels(
desc *Desc, metrics []metricWithLabelValues, labels Labels, curry []curriedLabelValue,
) int {
for i, metric := range metrics {
if matchLabels(desc, metric.values, labels, curry) {
return i
}
}
return len(metrics)
}
func matchLabelValues(values, lvs []string, curry []curriedLabelValue) bool {
if len(values) != len(lvs)+len(curry) {
return false
}
var iLVs, iCurry int
for i, v := range values {
if iCurry < len(curry) && curry[iCurry].index == i {
if v != curry[iCurry].value {
return false
}
iCurry++
continue
}
if v != lvs[iLVs] {
return false
}
iLVs++
}
return true
}
func matchLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool {
if len(values) != len(labels)+len(curry) {
return false
}
iCurry := 0
for i, k := range desc.variableLabels.names {
if iCurry < len(curry) && curry[iCurry].index == i {
if values[i] != curry[iCurry].value {
return false
}
iCurry++
continue
}
if values[i] != labels[k] {
return false
}
}
return true
}
func extractLabelValues(desc *Desc, labels Labels, curry []curriedLabelValue) []string {
labelValues := make([]string, len(labels)+len(curry))
iCurry := 0
for i, k := range desc.variableLabels.names {
if iCurry < len(curry) && curry[iCurry].index == i {
labelValues[i] = curry[iCurry].value
iCurry++
continue
}
labelValues[i] = labels[k]
}
return labelValues
}
func inlineLabelValues(lvs []string, curry []curriedLabelValue) []string {
labelValues := make([]string, len(lvs)+len(curry))
var iCurry, iLVs int
for i := range labelValues {
if iCurry < len(curry) && curry[iCurry].index == i {
labelValues[i] = curry[iCurry].value
iCurry++
continue
}
labelValues[i] = lvs[iLVs]
iLVs++
}
return labelValues
}
var labelsPool = &sync.Pool{
New: func() interface{} {
return make(Labels)
},
}
func constrainLabels(desc *Desc, labels Labels) (Labels, func()) {
if len(desc.variableLabels.labelConstraints) == 0 {
// Fast path when there's no constraints
return labels, func() {}
}
constrainedLabels := labelsPool.Get().(Labels)
for l, v := range labels {
constrainedLabels[l] = desc.variableLabels.constrain(l, v)
}
return constrainedLabels, func() {
for k := range constrainedLabels {
delete(constrainedLabels, k)
}
labelsPool.Put(constrainedLabels)
}
}
func constrainLabelValues(desc *Desc, lvs []string, curry []curriedLabelValue) []string {
if len(desc.variableLabels.labelConstraints) == 0 {
// Fast path when there's no constraints
return lvs
}
constrainedValues := make([]string, len(lvs))
var iCurry, iLVs int
for i := 0; i < len(lvs)+len(curry); i++ {
if iCurry < len(curry) && curry[iCurry].index == i {
iCurry++
continue
}
if i < len(desc.variableLabels.names) {
constrainedValues[iLVs] = desc.variableLabels.constrain(
desc.variableLabels.names[i],
lvs[iLVs],
)
} else {
constrainedValues[iLVs] = lvs[iLVs]
}
iLVs++
}
return constrainedValues
}

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// Copyright 2022 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
type v2 struct{}
// V2 is a struct that can be referenced to access experimental API that might
// be present in v2 of client golang someday. It offers extended functionality
// of v1 with slightly changed API. It is acceptable to use some pieces from v1
// and e.g `prometheus.NewGauge` and some from v2 e.g. `prometheus.V2.NewDesc`
// in the same codebase.
var V2 = v2{}

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@ -0,0 +1,214 @@
// Copyright 2018 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prometheus
import (
"fmt"
"sort"
"github.com/prometheus/client_golang/prometheus/internal"
dto "github.com/prometheus/client_model/go"
"google.golang.org/protobuf/proto"
)
// WrapRegistererWith returns a Registerer wrapping the provided
// Registerer. Collectors registered with the returned Registerer will be
// registered with the wrapped Registerer in a modified way. The modified
// Collector adds the provided Labels to all Metrics it collects (as
// ConstLabels). The Metrics collected by the unmodified Collector must not
// duplicate any of those labels. Wrapping a nil value is valid, resulting
// in a no-op Registerer.
//
// WrapRegistererWith provides a way to add fixed labels to a subset of
// Collectors. It should not be used to add fixed labels to all metrics
// exposed. See also
// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels-not-static-scraped-labels
//
// Conflicts between Collectors registered through the original Registerer with
// Collectors registered through the wrapping Registerer will still be
// detected. Any AlreadyRegisteredError returned by the Register method of
// either Registerer will contain the ExistingCollector in the form it was
// provided to the respective registry.
//
// The Collector example demonstrates a use of WrapRegistererWith.
func WrapRegistererWith(labels Labels, reg Registerer) Registerer {
return &wrappingRegisterer{
wrappedRegisterer: reg,
labels: labels,
}
}
// WrapRegistererWithPrefix returns a Registerer wrapping the provided
// Registerer. Collectors registered with the returned Registerer will be
// registered with the wrapped Registerer in a modified way. The modified
// Collector adds the provided prefix to the name of all Metrics it collects.
// Wrapping a nil value is valid, resulting in a no-op Registerer.
//
// WrapRegistererWithPrefix is useful to have one place to prefix all metrics of
// a sub-system. To make this work, register metrics of the sub-system with the
// wrapping Registerer returned by WrapRegistererWithPrefix. It is rarely useful
// to use the same prefix for all metrics exposed. In particular, do not prefix
// metric names that are standardized across applications, as that would break
// horizontal monitoring, for example the metrics provided by the Go collector
// (see NewGoCollector) and the process collector (see NewProcessCollector). (In
// fact, those metrics are already prefixed with “go_” or “process_”,
// respectively.)
//
// Conflicts between Collectors registered through the original Registerer with
// Collectors registered through the wrapping Registerer will still be
// detected. Any AlreadyRegisteredError returned by the Register method of
// either Registerer will contain the ExistingCollector in the form it was
// provided to the respective registry.
func WrapRegistererWithPrefix(prefix string, reg Registerer) Registerer {
return &wrappingRegisterer{
wrappedRegisterer: reg,
prefix: prefix,
}
}
type wrappingRegisterer struct {
wrappedRegisterer Registerer
prefix string
labels Labels
}
func (r *wrappingRegisterer) Register(c Collector) error {
if r.wrappedRegisterer == nil {
return nil
}
return r.wrappedRegisterer.Register(&wrappingCollector{
wrappedCollector: c,
prefix: r.prefix,
labels: r.labels,
})
}
func (r *wrappingRegisterer) MustRegister(cs ...Collector) {
if r.wrappedRegisterer == nil {
return
}
for _, c := range cs {
if err := r.Register(c); err != nil {
panic(err)
}
}
}
func (r *wrappingRegisterer) Unregister(c Collector) bool {
if r.wrappedRegisterer == nil {
return false
}
return r.wrappedRegisterer.Unregister(&wrappingCollector{
wrappedCollector: c,
prefix: r.prefix,
labels: r.labels,
})
}
type wrappingCollector struct {
wrappedCollector Collector
prefix string
labels Labels
}
func (c *wrappingCollector) Collect(ch chan<- Metric) {
wrappedCh := make(chan Metric)
go func() {
c.wrappedCollector.Collect(wrappedCh)
close(wrappedCh)
}()
for m := range wrappedCh {
ch <- &wrappingMetric{
wrappedMetric: m,
prefix: c.prefix,
labels: c.labels,
}
}
}
func (c *wrappingCollector) Describe(ch chan<- *Desc) {
wrappedCh := make(chan *Desc)
go func() {
c.wrappedCollector.Describe(wrappedCh)
close(wrappedCh)
}()
for desc := range wrappedCh {
ch <- wrapDesc(desc, c.prefix, c.labels)
}
}
func (c *wrappingCollector) unwrapRecursively() Collector {
switch wc := c.wrappedCollector.(type) {
case *wrappingCollector:
return wc.unwrapRecursively()
default:
return wc
}
}
type wrappingMetric struct {
wrappedMetric Metric
prefix string
labels Labels
}
func (m *wrappingMetric) Desc() *Desc {
return wrapDesc(m.wrappedMetric.Desc(), m.prefix, m.labels)
}
func (m *wrappingMetric) Write(out *dto.Metric) error {
if err := m.wrappedMetric.Write(out); err != nil {
return err
}
if len(m.labels) == 0 {
// No wrapping labels.
return nil
}
for ln, lv := range m.labels {
out.Label = append(out.Label, &dto.LabelPair{
Name: proto.String(ln),
Value: proto.String(lv),
})
}
sort.Sort(internal.LabelPairSorter(out.Label))
return nil
}
func wrapDesc(desc *Desc, prefix string, labels Labels) *Desc {
constLabels := Labels{}
for _, lp := range desc.constLabelPairs {
constLabels[*lp.Name] = *lp.Value
}
for ln, lv := range labels {
if _, alreadyUsed := constLabels[ln]; alreadyUsed {
return &Desc{
fqName: desc.fqName,
help: desc.help,
variableLabels: desc.variableLabels,
constLabelPairs: desc.constLabelPairs,
err: fmt.Errorf("attempted wrapping with already existing label name %q", ln),
}
}
constLabels[ln] = lv
}
// NewDesc will do remaining validations.
newDesc := V2.NewDesc(prefix+desc.fqName, desc.help, desc.variableLabels, constLabels)
// Propagate errors if there was any. This will override any errer
// created by NewDesc above, i.e. earlier errors get precedence.
if desc.err != nil {
newDesc.err = desc.err
}
return newDesc
}