ref: 5aba680979d4c267ad5b279810d24c85fdf208b1
dir: /logger/logger.go/
package logger
import (
"fmt"
"io"
goLog "log"
"os"
"sync"
)
// Sink for Go's log pkg
var Sink io.Writer
var Quiet bool
var Log *Logger
var gl *goLog.Logger
func Init() {
gl = goLog.New(os.Stderr, "", goLog.LstdFlags)
Log = &Logger{}
if Quiet {
Sink = &NullWriter{}
goLog.SetOutput(Sink)
}
}
type NullWriter struct{}
func (w *NullWriter) Write(p []byte) (n int, err error) {
n = len(p)
return
}
type Logger struct {
Debug bool
mu sync.Mutex
last string
lastSev int
repeated int
}
func (l *Logger) Printf(format string, v ...interface{}) {
l.emit(debug, format, v...)
}
func (l *Logger) Infof(format string, v ...interface{}) {
l.emit(info, format, v...)
}
func (l *Logger) Errorf(format string, v ...interface{}) {
l.emit(er, format, v...)
}
func (l *Logger) Fatal(v ...interface{}) {
gl.Fatal(v...)
}
func (l *Logger) Fatalf(format string, v ...interface{}) {
gl.Fatalf(format, v...)
}
const (
debug = iota
print
info
er
fatal
flush
)
func (l *Logger) Flush() {
l.emit(flush, "")
}
func (l *Logger) emit(severity int, format string, v ...interface{}) {
l.mu.Lock()
defer l.mu.Unlock()
if severity == debug && !l.Debug {
return
}
if (severity != fatal && severity != flush) && Quiet {
return
}
msg := fmt.Sprintf(format, v...)
switch {
case l.last == msg && l.lastSev == severity:
l.repeated++
case l.repeated > 0:
goLog.Printf("...and %v more", l.repeated)
l.repeated = 0
fallthrough
default:
switch severity {
case debug:
gl.Printf(format, v...)
case info:
gl.Printf(format, v...)
case er:
gl.Printf(format, v...)
case fatal:
gl.Fatalf(format, v...)
case flush:
}
}
l.last = msg
l.lastSev = severity
}