ref: ac3f6f558ed463b977e9a83e7b37555720b662ce
dir: /logger/logger.go/
package logger import ( "fmt" "io" goLog "log" "os" ) // 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 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{}) { 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 }