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本文次要钻研一下golang的zap的NewDevelopment
NewDevelopment
zap@v1.16.0/logger.go
func NewDevelopment(options ...Option) (*Logger, error) { return NewDevelopmentConfig().Build(options...)}NewDevelopment应用NewDevelopmentConfig进行build
NewDevelopmentConfig
zap@v1.16.0/config.go
func NewDevelopmentConfig() Config { return Config{ Level: NewAtomicLevelAt(DebugLevel), Development: true, Encoding: "console", EncoderConfig: NewDevelopmentEncoderConfig(), OutputPaths: []string{"stderr"}, ErrorOutputPaths: []string{"stderr"}, }}NewDevelopmentConfig创立Config，其Level为NewAtomicLevelAt(DebugLevel)，Development为true，Encoding为console，EncoderConfig为NewDevelopmentEncoderConfig，OutputPaths及ErrorOutputPaths均为stderr
NewDevelopmentEncoderConfig
zap@v1.16.0/config.go
func NewDevelopmentEncoderConfig() zapcore.EncoderConfig { return zapcore.EncoderConfig{ // Keys can be anything except the empty string. TimeKey: "T", LevelKey: "L", NameKey: "N", CallerKey: "C", FunctionKey: zapcore.OmitKey, MessageKey: "M", StacktraceKey: "S", LineEnding: zapcore.DefaultLineEnding, EncodeLevel: zapcore.CapitalLevelEncoder, EncodeTime: zapcore.ISO8601TimeEncoder, EncodeDuration: zapcore.StringDurationEncoder, EncodeCaller: zapcore.ShortCallerEncoder, }}NewDevelopmentEncoderConfig创立zapcore.EncoderConfig，其LineEnding为zapcore.DefaultLineEnding，EncodeLevel为zapcore.CapitalLevelEncoder，EncodeTime为zapcore.ISO8601TimeEncoder，EncodeDuration为zapcore.StringDurationEncoder，EncodeCaller为zapcore.ShortCallerEncoder
encoder
zap@v1.16.0/zapcore/encoder.go
const DefaultLineEnding = "\n"func CapitalLevelEncoder(l Level, enc PrimitiveArrayEncoder) { enc.AppendString(l.CapitalString())}func ISO8601TimeEncoder(t time.Time, enc PrimitiveArrayEncoder) { encodeTimeLayout(t, "2006-01-02T15:04:05.000Z0700", enc)}func StringDurationEncoder(d time.Duration, enc PrimitiveArrayEncoder) { enc.AppendString(d.String())}func ShortCallerEncoder(caller EntryCaller, enc PrimitiveArrayEncoder) { // TODO: consider using a byte-oriented API to save an allocation. enc.AppendString(caller.TrimmedPath())}encoder
zap@v1.16.0/encoder.go
var ( errNoEncoderNameSpecified = errors.New("no encoder name specified") _encoderNameToConstructor = map[string]func(zapcore.EncoderConfig) (zapcore.Encoder, error){ "console": func(encoderConfig zapcore.EncoderConfig) (zapcore.Encoder, error) { return zapcore.NewConsoleEncoder(encoderConfig), nil }, "json": func(encoderConfig zapcore.EncoderConfig) (zapcore.Encoder, error) { return zapcore.NewJSONEncoder(encoderConfig), nil }, } _encoderMutex sync.RWMutex)_encoderNameToConstructor内置了console、json两种encoder
NewConsoleEncoder
zap@v1.16.0/console_encoder.go
func NewConsoleEncoder(cfg EncoderConfig) Encoder { if len(cfg.ConsoleSeparator) == 0 { // Use a default delimiter of '\t' for backwards compatibility cfg.ConsoleSeparator = "\t" } return consoleEncoder{newJSONEncoder(cfg, true)}}type consoleEncoder struct { *jsonEncoder}func (c consoleEncoder) EncodeEntry(ent Entry, fields []Field) (*buffer.Buffer, error) { line := bufferpool.Get() // We don't want the entry's metadata to be quoted and escaped (if it's // encoded as strings), which means that we can't use the JSON encoder. The // simplest option is to use the memory encoder and fmt.Fprint. // // If this ever becomes a performance bottleneck, we can implement // ArrayEncoder for our plain-text format. arr := getSliceEncoder() if c.TimeKey != "" && c.EncodeTime != nil { c.EncodeTime(ent.Time, arr) } if c.LevelKey != "" && c.EncodeLevel != nil { c.EncodeLevel(ent.Level, arr) } if ent.LoggerName != "" && c.NameKey != "" { nameEncoder := c.EncodeName if nameEncoder == nil { // Fall back to FullNameEncoder for backward compatibility. nameEncoder = FullNameEncoder } nameEncoder(ent.LoggerName, arr) } if ent.Caller.Defined { if c.CallerKey != "" && c.EncodeCaller != nil { c.EncodeCaller(ent.Caller, arr) } if c.FunctionKey != "" { arr.AppendString(ent.Caller.Function) } } for i := range arr.elems { if i > 0 { line.AppendString(c.ConsoleSeparator) } fmt.Fprint(line, arr.elems[i]) } putSliceEncoder(arr) // Add the message itself. if c.MessageKey != "" { c.addSeparatorIfNecessary(line) line.AppendString(ent.Message) } // Add any structured context. c.writeContext(line, fields) // If there's no stacktrace key, honor that; this allows users to force // single-line output. if ent.Stack != "" && c.StacktraceKey != "" { line.AppendByte('\n') line.AppendString(ent.Stack) } if c.LineEnding != "" { line.AppendString(c.LineEnding) } else { line.AppendString(DefaultLineEnding) } return line, nil}consoleEncoder内嵌了*jsonEncoder，其EncodeEntry办法通过getSliceEncoder()获取`*sliceArrayEncoder，而后顺次往arr增加time、level、loggerName、caller，最初再增加业务的message自身，对于有stacktrace还会追加stacktrace实例
func developmentDemo() { logger, _ := zap.NewDevelopment() defer logger.Sync() // flushes buffer, if any sugar := logger.Sugar() sugar.Info("this will be logged") sugar.Panic("test panic")}输入
2020-12-06T23:29:08.081+0800 INFO log-demo/zap_demo.go:17 this will be logged2020-12-06T23:29:08.082+0800 PANIC log-demo/zap_demo.go:18 test panicmain.developmentDemo /zap_demo.go:18main.main /zap_demo.go:10runtime.main /usr/local/go/src/runtime/proc.go:204panic: test panicgoroutine 1 [running]:go.uber.org/zap/zapcore.(*CheckedEntry).Write(0xc0000f20c0, 0x0, 0x0, 0x0) /go/pkg/mod/go.uber.org/zap@v1.16.0/zapcore/entry.go:234 +0x585go.uber.org/zap.(*SugaredLogger).log(0xc0000fbed0, 0x4, 0x0, 0x0, 0xc0000fbed8, 0x1, 0x1, 0x0, 0x0, 0x0) /go/pkg/mod/go.uber.org/zap@v1.16.0/sugar.go:234 +0xf6go.uber.org/zap.(*SugaredLogger).Panic(...) /go/pkg/mod/go.uber.org/zap@v1.16.0/sugar.go:123main.developmentDemo() /zap_demo.go:18 +0x199main.main() /zap_demo.go:10 +0x25exit status 2小结
NewDevelopmentEncoderConfig创立zapcore.EncoderConfig，其LineEnding为zapcore.DefaultLineEnding，EncodeLevel为zapcore.CapitalLevelEncoder，EncodeTime为zapcore.ISO8601TimeEncoder，EncodeDuration为zapcore.StringDurationEncoder，EncodeCaller为zapcore.ShortCallerEncoder
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