github.com/Laisky/zap@v1.27.0/.readme.tmpl (about)

     1  # :zap: zap [![GoDoc][doc-img]][doc] [![Build Status][ci-img]][ci] [![Coverage Status][cov-img]][cov]
     2  
     3  <div align="center">
     4  
     5  Blazing fast, structured, leveled logging in Go.
     6  
     7  ![Zap logo](assets/logo.png)
     8  
     9  [![GoDoc][doc-img]][doc] [![Build Status][ci-img]][ci] [![Coverage Status][cov-img]][cov]
    10  
    11  </div>
    12  
    13  ## Installation
    14  
    15  `go get -u github.com/Laisky/zap`
    16  
    17  Note that zap only supports the two most recent minor versions of Go.
    18  
    19  ## Quick Start
    20  
    21  In contexts where performance is nice, but not critical, use the
    22  `SugaredLogger`. It's 4-10x faster than other structured logging
    23  packages and includes both structured and `printf`-style APIs.
    24  
    25  ```go
    26  logger, _ := zap.NewProduction()
    27  defer logger.Sync() // flushes buffer, if any
    28  sugar := logger.Sugar()
    29  sugar.Infow("failed to fetch URL",
    30    // Structured context as loosely typed key-value pairs.
    31    "url", url,
    32    "attempt", 3,
    33    "backoff", time.Second,
    34  )
    35  sugar.Infof("Failed to fetch URL: %s", url)
    36  ```
    37  
    38  When performance and type safety are critical, use the `Logger`. It's even
    39  faster than the `SugaredLogger` and allocates far less, but it only supports
    40  structured logging.
    41  
    42  ```go
    43  logger, _ := zap.NewProduction()
    44  defer logger.Sync()
    45  logger.Info("failed to fetch URL",
    46    // Structured context as strongly typed Field values.
    47    zap.String("url", url),
    48    zap.Int("attempt", 3),
    49    zap.Duration("backoff", time.Second),
    50  )
    51  ```
    52  
    53  See the [documentation][doc] and [FAQ](FAQ.md) for more details.
    54  
    55  ## Performance
    56  
    57  For applications that log in the hot path, reflection-based serialization and
    58  string formatting are prohibitively expensive &mdash; they're CPU-intensive
    59  and make many small allocations. Put differently, using `encoding/json` and
    60  `fmt.Fprintf` to log tons of `interface{}`s makes your application slow.
    61  
    62  Zap takes a different approach. It includes a reflection-free, zero-allocation
    63  JSON encoder, and the base `Logger` strives to avoid serialization overhead
    64  and allocations wherever possible. By building the high-level `SugaredLogger`
    65  on that foundation, zap lets users *choose* when they need to count every
    66  allocation and when they'd prefer a more familiar, loosely typed API.
    67  
    68  As measured by its own [benchmarking suite][], not only is zap more performant
    69  than comparable structured logging packages &mdash; it's also faster than the
    70  standard library. Like all benchmarks, take these with a grain of salt.<sup
    71  id="anchor-versions">[1](#footnote-versions)</sup>
    72  
    73  Log a message and 10 fields:
    74  
    75  {{.BenchmarkAddingFields}}
    76  
    77  Log a message with a logger that already has 10 fields of context:
    78  
    79  {{.BenchmarkAccumulatedContext}}
    80  
    81  Log a static string, without any context or `printf`-style templating:
    82  
    83  {{.BenchmarkWithoutFields}}
    84  
    85  ## Development Status: Stable
    86  
    87  All APIs are finalized, and no breaking changes will be made in the 1.x series
    88  of releases. Users of semver-aware dependency management systems should pin
    89  zap to `^1`.
    90  
    91  ## Contributing
    92  
    93  We encourage and support an active, healthy community of contributors &mdash;
    94  including you! Details are in the [contribution guide](CONTRIBUTING.md) and
    95  the [code of conduct](CODE_OF_CONDUCT.md). The zap maintainers keep an eye on
    96  issues and pull requests, but you can also report any negative conduct to
    97  oss-conduct@uber.com. That email list is a private, safe space; even the zap
    98  maintainers don't have access, so don't hesitate to hold us to a high
    99  standard.
   100  
   101  <hr>
   102  
   103  Released under the [MIT License](LICENSE).
   104  
   105  <sup id="footnote-versions">1</sup> In particular, keep in mind that we may be
   106  benchmarking against slightly older versions of other packages. Versions are
   107  pinned in the [benchmarks/go.mod][] file. [↩](#anchor-versions)
   108  
   109  [doc-img]: https://pkg.go.dev/badge/github.com/Laisky/zap
   110  [doc]: https://pkg.go.dev/github.com/Laisky/zap
   111  [ci-img]: https://github.com/uber-go/zap/actions/workflows/go.yml/badge.svg
   112  [ci]: https://github.com/uber-go/zap/actions/workflows/go.yml
   113  [cov-img]: https://codecov.io/gh/uber-go/zap/branch/master/graph/badge.svg
   114  [cov]: https://codecov.io/gh/uber-go/zap
   115  [benchmarking suite]: https://github.com/uber-go/zap/tree/master/benchmarks
   116  [benchmarks/go.mod]: https://github.com/uber-go/zap/blob/master/benchmarks/go.mod