⚡ zap 
Go 中快速、结构化、分级的日志记录。
安装
go get -u go.uber.org/zap
请注意，zap 仅支持 Go 的两个最新次要版本。
Quick Start
在性能良好但不重要的情况下，使用 SugaredLogger. 它比其他结构化日志记录包快 4-10 倍，并且包括结构化和printf样式 API。
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)
当性能和类型安全至关重要时，请使用Logger. 它甚至比 the 还要快，SugaredLogger并且分配得更少，但它只支持结构化日志记录。
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 and FAQ for more details.
Performance
对于登录热路径的应用程序，基于反射的序列化和字符串格式化非常昂贵——它们是 CPU 密集型的并且会进行许多小分配。换句话说，使用encoding/jsonand fmt.Fprintf记录大量的interface{}s 会使您的应用程序变慢。
Zap 采取了不同的方法。它包括一个无反射、零分配的 JSON 编码器，并且基础Logger尽可能避免序列化开销和分配。SugaredLogger 通过在此基础上构建高级，zap 允许用户选择何时需要计算每个分配，以及何时他们更喜欢更熟悉、松散类型的 API。
根据其自己的基准测试套件衡量，zap 不仅比同类结构化日志记录包性能更高，而且比标准库更快。像所有基准一样，对这些基准持保留态度。1
记录一条消息和 10 个字段：
| Package | Time | Time % to zap | Objects Allocated |
|---|---|---|---|
| ⚡ zap | 2900 ns/op | +0% | 5 allocs/op |
| ⚡ zap (sugared) | 3475 ns/op | +20% | 10 allocs/op |
| zerolog | 10639 ns/op | +267% | 32 allocs/op |
| go-kit | 14434 ns/op | +398% | 59 allocs/op |
| logrus | 17104 ns/op | +490% | 81 allocs/op |
| apex/log | 32424 ns/op | +1018% | 66 allocs/op |
| log15 | 33579 ns/op | +1058% | 76 allocs/op |
使用已经有 10 个上下文字段的记录器记录消息：
| Package | Time | Time % to zap | Objects Allocated |
|---|---|---|---|
| ⚡ zap | 373 ns/op | +0% | 0 allocs/op |
| ⚡ zap (sugared) | 452 ns/op | +21% | 1 allocs/op |
| zerolog | 288 ns/op | -23% | 0 allocs/op |
| go-kit | 11785 ns/op | +3060% | 58 allocs/op |
| logrus | 19629 ns/op | +5162% | 70 allocs/op |
| log15 | 21866 ns/op | +5762% | 72 allocs/op |
| apex/log | 30890 ns/op | +8182% | 55 allocs/op |
记录一个静态字符串，没有任何上下文或 printf-style 模板：
| Package | Time | Time % to zap | Objects Allocated |
|---|---|---|---|
| ⚡ zap | 381 ns/op | +0% | 0 allocs/op |
| ⚡ zap (sugared) | 410 ns/op | +8% | 1 allocs/op |
| zerolog | 369 ns/op | -3% | 0 allocs/op |
| standard library | 385 ns/op | +1% | 2 allocs/op |
| go-kit | 606 ns/op | +59% | 11 allocs/op |
| logrus | 1730 ns/op | +354% | 25 allocs/op |
| apex/log | 1998 ns/op | +424% | 7 allocs/op |
| log15 | 4546 ns/op | +1093% | 22 allocs/op |
Development Status: Stable
所有 API 均已完成，在 1.x 系列版本中不会进行重大更改。semver-aware 依赖管理系统的用户应该将 zap 固定到^1.
Contributing
We encourage and support an active, healthy community of contributors —
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 the [benchmarks/go.mod][] file. [↩](#anchor-versions)