open-consul/vendor/github.com/hashicorp/go-hclog/global.go

63 lines
1.8 KiB
Go

package hclog
import (
"sync"
)
var (
protect sync.Once
def Logger
// DefaultOptions is used to create the Default logger. These are read
// only when the Default logger is created, so set them as soon as the
// process starts.
DefaultOptions = &LoggerOptions{
Level: DefaultLevel,
Output: DefaultOutput,
}
)
// Default returns a globally held logger. This can be a good starting
// place, and then you can use .With() and .Name() to create sub-loggers
// to be used in more specific contexts.
// The value of the Default logger can be set via SetDefault() or by
// changing the options in DefaultOptions.
//
// This method is goroutine safe, returning a global from memory, but
// cause should be used if SetDefault() is called it random times
// in the program as that may result in race conditions and an unexpected
// Logger being returned.
func Default() Logger {
protect.Do(func() {
// If SetDefault was used before Default() was called, we need to
// detect that here.
if def == nil {
def = New(DefaultOptions)
}
})
return def
}
// L is a short alias for Default().
func L() Logger {
return Default()
}
// SetDefault changes the logger to be returned by Default()and L()
// to the one given. This allows packages to use the default logger
// and have higher level packages change it to match the execution
// environment. It returns any old default if there is one.
//
// NOTE: This is expected to be called early in the program to setup
// a default logger. As such, it does not attempt to make itself
// not racy with regard to the value of the default logger. Ergo
// if it is called in goroutines, you may experience race conditions
// with other goroutines retrieving the default logger. Basically,
// don't do that.
func SetDefault(log Logger) Logger {
old := def
def = log
return old
}