vendor files

vendor/k8s.io/client-go/util/workqueue/metrics.go

@@ -0,0 +1,195 @@
+/*
+Copyright 2016 The Kubernetes 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 workqueue
+
+import (
+	"sync"
+	"time"
+)
+
+// This file provides abstractions for setting the provider (e.g., prometheus)
+// of metrics.
+
+type queueMetrics interface {
+	add(item t)
+	get(item t)
+	done(item t)
+}
+
+// GaugeMetric represents a single numerical value that can arbitrarily go up
+// and down.
+type GaugeMetric interface {
+	Inc()
+	Dec()
+}
+
+// CounterMetric represents a single numerical value that only ever
+// goes up.
+type CounterMetric interface {
+	Inc()
+}
+
+// SummaryMetric captures individual observations.
+type SummaryMetric interface {
+	Observe(float64)
+}
+
+type noopMetric struct{}
+
+func (noopMetric) Inc()            {}
+func (noopMetric) Dec()            {}
+func (noopMetric) Observe(float64) {}
+
+type defaultQueueMetrics struct {
+	// current depth of a workqueue
+	depth GaugeMetric
+	// total number of adds handled by a workqueue
+	adds CounterMetric
+	// how long an item stays in a workqueue
+	latency SummaryMetric
+	// how long processing an item from a workqueue takes
+	workDuration         SummaryMetric
+	addTimes             map[t]time.Time
+	processingStartTimes map[t]time.Time
+}
+
+func (m *defaultQueueMetrics) add(item t) {
+	if m == nil {
+		return
+	}
+
+	m.adds.Inc()
+	m.depth.Inc()
+	if _, exists := m.addTimes[item]; !exists {
+		m.addTimes[item] = time.Now()
+	}
+}
+
+func (m *defaultQueueMetrics) get(item t) {
+	if m == nil {
+		return
+	}
+
+	m.depth.Dec()
+	m.processingStartTimes[item] = time.Now()
+	if startTime, exists := m.addTimes[item]; exists {
+		m.latency.Observe(sinceInMicroseconds(startTime))
+		delete(m.addTimes, item)
+	}
+}
+
+func (m *defaultQueueMetrics) done(item t) {
+	if m == nil {
+		return
+	}
+
+	if startTime, exists := m.processingStartTimes[item]; exists {
+		m.workDuration.Observe(sinceInMicroseconds(startTime))
+		delete(m.processingStartTimes, item)
+	}
+}
+
+// Gets the time since the specified start in microseconds.
+func sinceInMicroseconds(start time.Time) float64 {
+	return float64(time.Since(start).Nanoseconds() / time.Microsecond.Nanoseconds())
+}
+
+type retryMetrics interface {
+	retry()
+}
+
+type defaultRetryMetrics struct {
+	retries CounterMetric
+}
+
+func (m *defaultRetryMetrics) retry() {
+	if m == nil {
+		return
+	}
+
+	m.retries.Inc()
+}
+
+// MetricsProvider generates various metrics used by the queue.
+type MetricsProvider interface {
+	NewDepthMetric(name string) GaugeMetric
+	NewAddsMetric(name string) CounterMetric
+	NewLatencyMetric(name string) SummaryMetric
+	NewWorkDurationMetric(name string) SummaryMetric
+	NewRetriesMetric(name string) CounterMetric
+}
+
+type noopMetricsProvider struct{}
+
+func (_ noopMetricsProvider) NewDepthMetric(name string) GaugeMetric {
+	return noopMetric{}
+}
+
+func (_ noopMetricsProvider) NewAddsMetric(name string) CounterMetric {
+	return noopMetric{}
+}
+
+func (_ noopMetricsProvider) NewLatencyMetric(name string) SummaryMetric {
+	return noopMetric{}
+}
+
+func (_ noopMetricsProvider) NewWorkDurationMetric(name string) SummaryMetric {
+	return noopMetric{}
+}
+
+func (_ noopMetricsProvider) NewRetriesMetric(name string) CounterMetric {
+	return noopMetric{}
+}
+
+var metricsFactory = struct {
+	metricsProvider MetricsProvider
+	setProviders    sync.Once
+}{
+	metricsProvider: noopMetricsProvider{},
+}
+
+func newQueueMetrics(name string) queueMetrics {
+	var ret *defaultQueueMetrics
+	if len(name) == 0 {
+		return ret
+	}
+	return &defaultQueueMetrics{
+		depth:                metricsFactory.metricsProvider.NewDepthMetric(name),
+		adds:                 metricsFactory.metricsProvider.NewAddsMetric(name),
+		latency:              metricsFactory.metricsProvider.NewLatencyMetric(name),
+		workDuration:         metricsFactory.metricsProvider.NewWorkDurationMetric(name),
+		addTimes:             map[t]time.Time{},
+		processingStartTimes: map[t]time.Time{},
+	}
+}
+
+func newRetryMetrics(name string) retryMetrics {
+	var ret *defaultRetryMetrics
+	if len(name) == 0 {
+		return ret
+	}
+	return &defaultRetryMetrics{
+		retries: metricsFactory.metricsProvider.NewRetriesMetric(name),
+	}
+}
+
+// SetProvider sets the metrics provider of the metricsFactory.
+func SetProvider(metricsProvider MetricsProvider) {
+	metricsFactory.setProviders.Do(func() {
+		metricsFactory.metricsProvider = metricsProvider
+	})
+}