ceph-csi/vendor/go.uber.org/zap/.readme.tmpl
Niels de Vos 91774fc936 rebase: vendor dependencies for Vault API
Uses github.com/libopenstorage/secrets to communicate with Vault. This
removes the need for maintaining our own limited Vault APIs.

By adding the new dependency, several other packages got updated in the
process. Unused indirect dependencies have been removed from go.mod.

Signed-off-by: Niels de Vos <ndevos@redhat.com>
2020-11-29 04:03:59 +00:00

109 lines
3.8 KiB
Cheetah

# :zap: zap [![GoDoc][doc-img]][doc] [![Build Status][ci-img]][ci] [![Coverage Status][cov-img]][cov]
Blazing fast, structured, leveled logging in Go.
## Installation
`go get -u go.uber.org/zap`
Note that zap only supports the two most recent minor versions of Go.
## Quick Start
In contexts where performance is nice, but not critical, use the
`SugaredLogger`. It's 4-10x faster than other structured logging
packages and includes both structured and `printf`-style APIs.
```go
logger, _ := zap.NewProduction()
defer logger.Sync() // flushes buffer, if any
sugar := logger.Sugar()
sugar.Infow("failed to fetch URL",
// Structured context as loosely typed key-value pairs.
"url", url,
"attempt", 3,
"backoff", time.Second,
)
sugar.Infof("Failed to fetch URL: %s", url)
```
When performance and type safety are critical, use the `Logger`. It's even
faster than the `SugaredLogger` and allocates far less, but it only supports
structured logging.
```go
logger, _ := zap.NewProduction()
defer logger.Sync()
logger.Info("failed to fetch URL",
// Structured context as strongly typed Field values.
zap.String("url", url),
zap.Int("attempt", 3),
zap.Duration("backoff", time.Second),
)
```
See the [documentation][doc] and [FAQ](FAQ.md) for more details.
## Performance
For applications that log in the hot path, reflection-based serialization and
string formatting are prohibitively expensive &mdash; they're CPU-intensive
and make many small allocations. Put differently, using `encoding/json` and
`fmt.Fprintf` to log tons of `interface{}`s makes your application slow.
Zap takes a different approach. It includes a reflection-free, zero-allocation
JSON encoder, and the base `Logger` strives to avoid serialization overhead
and allocations wherever possible. By building the high-level `SugaredLogger`
on that foundation, zap lets users *choose* when they need to count every
allocation and when they'd prefer a more familiar, loosely typed API.
As measured by its own [benchmarking suite][], not only is zap more performant
than comparable structured logging packages &mdash; it's also faster than the
standard library. Like all benchmarks, take these with a grain of salt.<sup
id="anchor-versions">[1](#footnote-versions)</sup>
Log a message and 10 fields:
{{.BenchmarkAddingFields}}
Log a message with a logger that already has 10 fields of context:
{{.BenchmarkAccumulatedContext}}
Log a static string, without any context or `printf`-style templating:
{{.BenchmarkWithoutFields}}
## Development Status: Stable
All APIs are finalized, and no breaking changes will be made in the 1.x series
of releases. Users of semver-aware dependency management systems should pin
zap to `^1`.
## Contributing
We encourage and support an active, healthy community of contributors &mdash;
including you! Details are in the [contribution guide](CONTRIBUTING.md) and
the [code of conduct](CODE_OF_CONDUCT.md). The zap maintainers keep an eye on
issues and pull requests, but you can also report any negative conduct to
oss-conduct@uber.com. That email list is a private, safe space; even the zap
maintainers don't have access, so don't hesitate to hold us to a high
standard.
<hr>
Released under the [MIT License](LICENSE.txt).
<sup id="footnote-versions">1</sup> In particular, keep in mind that we may be
benchmarking against slightly older versions of other packages. Versions are
pinned in zap's [glide.lock][] file. [↩](#anchor-versions)
[doc-img]: https://godoc.org/go.uber.org/zap?status.svg
[doc]: https://godoc.org/go.uber.org/zap
[ci-img]: https://travis-ci.org/uber-go/zap.svg?branch=master
[ci]: https://travis-ci.org/uber-go/zap
[cov-img]: https://codecov.io/gh/uber-go/zap/branch/master/graph/badge.svg
[cov]: https://codecov.io/gh/uber-go/zap
[benchmarking suite]: https://github.com/uber-go/zap/tree/master/benchmarks
[glide.lock]: https://github.com/uber-go/zap/blob/master/glide.lock