// Copyright (c) 2016 Uber Technologies, Inc. // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal // in the Software without restriction, including without limitation the rights // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. package zap import ( "fmt" "go.uber.org/zap/zapcore" ) // An Option configures a Logger. type Option interface { apply(*Logger) } // optionFunc wraps a func so it satisfies the Option interface. type optionFunc func(*Logger) func (f optionFunc) apply(log *Logger) { f(log) } // WrapCore wraps or replaces the Logger's underlying zapcore.Core. func WrapCore(f func(zapcore.Core) zapcore.Core) Option { return optionFunc(func(log *Logger) { log.core = f(log.core) }) } // Hooks registers functions which will be called each time the Logger writes // out an Entry. Repeated use of Hooks is additive. // // Hooks are useful for simple side effects, like capturing metrics for the // number of emitted logs. More complex side effects, including anything that // requires access to the Entry's structured fields, should be implemented as // a zapcore.Core instead. See zapcore.RegisterHooks for details. func Hooks(hooks ...func(zapcore.Entry) error) Option { return optionFunc(func(log *Logger) { log.core = zapcore.RegisterHooks(log.core, hooks...) }) } // Fields adds fields to the Logger. func Fields(fs ...Field) Option { return optionFunc(func(log *Logger) { log.core = log.core.With(fs) }) } // ErrorOutput sets the destination for errors generated by the Logger. Note // that this option only affects internal errors; for sample code that sends // error-level logs to a different location from info- and debug-level logs, // see the package-level AdvancedConfiguration example. // // The supplied WriteSyncer must be safe for concurrent use. The Open and // zapcore.Lock functions are the simplest ways to protect files with a mutex. func ErrorOutput(w zapcore.WriteSyncer) Option { return optionFunc(func(log *Logger) { log.errorOutput = w }) } // Development puts the logger in development mode, which makes DPanic-level // logs panic instead of simply logging an error. func Development() Option { return optionFunc(func(log *Logger) { log.development = true }) } // AddCaller configures the Logger to annotate each message with the filename, // line number, and function name of zap's caller. See also WithCaller. func AddCaller() Option { return WithCaller(true) } // WithCaller configures the Logger to annotate each message with the filename, // line number, and function name of zap's caller, or not, depending on the // value of enabled. This is a generalized form of AddCaller. func WithCaller(enabled bool) Option { return optionFunc(func(log *Logger) { log.addCaller = enabled }) } // AddCallerSkip increases the number of callers skipped by caller annotation // (as enabled by the AddCaller option). When building wrappers around the // Logger and SugaredLogger, supplying this Option prevents zap from always // reporting the wrapper code as the caller. func AddCallerSkip(skip int) Option { return optionFunc(func(log *Logger) { log.callerSkip += skip }) } // AddStacktrace configures the Logger to record a stack trace for all messages at // or above a given level. func AddStacktrace(lvl zapcore.LevelEnabler) Option { return optionFunc(func(log *Logger) { log.addStack = lvl }) } // IncreaseLevel increase the level of the logger. It has no effect if // the passed in level tries to decrease the level of the logger. func IncreaseLevel(lvl zapcore.LevelEnabler) Option { return optionFunc(func(log *Logger) { core, err := zapcore.NewIncreaseLevelCore(log.core, lvl) if err != nil { fmt.Fprintf(log.errorOutput, "failed to IncreaseLevel: %v\n", err) } else { log.core = core } }) } // WithPanicHook sets a CheckWriteHook to run on Panic/DPanic logs. // Zap will call this hook after writing a log statement with a Panic/DPanic level. // // For example, the following builds a logger that will exit the current // goroutine after writing a Panic/DPanic log message, but it will not start a panic. // // zap.New(core, zap.WithPanicHook(zapcore.WriteThenGoexit)) // // This is useful for testing Panic/DPanic log output. func WithPanicHook(hook zapcore.CheckWriteHook) Option { return optionFunc(func(log *Logger) { log.onPanic = hook }) } // OnFatal sets the action to take on fatal logs. // // Deprecated: Use [WithFatalHook] instead. func OnFatal(action zapcore.CheckWriteAction) Option { return WithFatalHook(action) } // WithFatalHook sets a CheckWriteHook to run on fatal logs. // Zap will call this hook after writing a log statement with a Fatal level. // // For example, the following builds a logger that will exit the current // goroutine after writing a fatal log message, but it will not exit the // program. // // zap.New(core, zap.WithFatalHook(zapcore.WriteThenGoexit)) // // It is important that the provided CheckWriteHook stops the control flow at // the current statement to meet expectations of callers of the logger. // We recommend calling os.Exit or runtime.Goexit inside custom hooks at // minimum. func WithFatalHook(hook zapcore.CheckWriteHook) Option { return optionFunc(func(log *Logger) { log.onFatal = hook }) } // WithClock specifies the clock used by the logger to determine the current // time for logged entries. Defaults to the system clock with time.Now. func WithClock(clock zapcore.Clock) Option { return optionFunc(func(log *Logger) { log.clock = clock }) }