ref: 62b73b4e51b6d2db873956a9df9671e9cc2116c4
dir: /logger/logger.go/
package log
import (
"fmt"
"io"
goLog "log"
"os"
"sync"
)
// Sink for Go's log pkg
var (
Sink io.Writer
quiet bool
gl *goLog.Logger
Debug bool
mu sync.Mutex
last string
lastSev int
repeated int
)
func init() {
gl = goLog.New(os.Stderr, "", goLog.LstdFlags)
}
func SetQuiet() {
mu.Lock()
defer mu.Unlock()
quiet = true
Sink = &NullWriter{}
goLog.SetOutput(Sink)
}
type NullWriter struct{}
func (w *NullWriter) Write(p []byte) (n int, err error) {
n = len(p)
return
}
func Printf(format string, v ...interface{}) {
emit(debug, format, v...)
}
func Infof(format string, v ...interface{}) {
emit(info, format, v...)
}
func Errorf(format string, v ...interface{}) {
emit(er, format, v...)
}
func Fatal(v ...interface{}) {
gl.Fatal(v...)
}
func Fatalf(format string, v ...interface{}) {
gl.Fatalf(format, v...)
}
const (
debug = iota
print
info
er
fatal
flush
)
func Flush() {
emit(flush, "")
}
func emit(severity int, format string, v ...interface{}) {
mu.Lock()
defer mu.Unlock()
if severity == debug && !Debug {
return
}
if (severity != fatal && severity != flush) && quiet {
return
}
msg := fmt.Sprintf(format, v...)
switch {
case last == msg && lastSev == severity:
repeated++
case repeated > 0:
goLog.Printf("...and %v more", repeated)
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:
}
}
last = msg
lastSev = severity
}