coredns/plugin/pkg/log/log.go
Miek Gieben a84413bd07
pkg/log: fix data race on d (#2698)
* pkg/log: fix data race on d

Wrap d in a mutex to prevent data race. This makes is slower, but this
is a debugging aid anyway. It's not used normally.

Signed-off-by: Miek Gieben <miek@miek.nl>

* Fix tests compilation

Signed-off-by: Miek Gieben <miek@miek.nl>

* Fix test compile

Signed-off-by: Miek Gieben <miek@miek.nl>
2019-05-23 21:02:30 +01:00

110 lines
3 KiB
Go

// Package log implements a small wrapper around the std lib log package.
// It implements log levels by prefixing the logs with the current time
// with in RFC3339Milli and [INFO], [DEBUG], [WARNING] or [ERROR].
// Debug logging is available and enabled if the *debug* plugin is used.
//
// log.Info("this is some logging"), will log on the Info level.
//
// log.Debug("this is debug output"), will log in the Debug level, etc.
package log
import (
"fmt"
"io/ioutil"
golog "log"
"os"
"sync"
"time"
)
// D controls whether we should output debug logs. If true, we do, once set
// it can not be unset.
var D = &d{}
type d struct {
on bool
sync.RWMutex
}
// Set sets d to true.
func (d *d) Set() {
d.Lock()
d.on = true
d.Unlock()
}
// Value return the boolean value of d.
func (d *d) Value() bool {
d.RLock()
b := d.on
d.RUnlock()
return b
}
// RFC3339Milli doesn't exist, invent it here.
func clock() string { return time.Now().Format("2006-01-02T15:04:05.000Z07:00") }
// logf calls log.Printf prefixed with level.
func logf(level, format string, v ...interface{}) {
golog.Print(clock(), level, fmt.Sprintf(format, v...))
}
// log calls log.Print prefixed with level.
func log(level string, v ...interface{}) {
golog.Print(clock(), level, fmt.Sprint(v...))
}
// Debug is equivalent to log.Print(), but prefixed with "[DEBUG] ". It only outputs something
// if D is true.
func Debug(v ...interface{}) {
if !D.Value() {
return
}
log(debug, v...)
}
// Debugf is equivalent to log.Printf(), but prefixed with "[DEBUG] ". It only outputs something
// if D is true.
func Debugf(format string, v ...interface{}) {
if !D.Value() {
return
}
logf(debug, format, v...)
}
// Info is equivalent to log.Print, but prefixed with "[INFO] ".
func Info(v ...interface{}) { log(info, v...) }
// Infof is equivalent to log.Printf, but prefixed with "[INFO] ".
func Infof(format string, v ...interface{}) { logf(info, format, v...) }
// Warning is equivalent to log.Print, but prefixed with "[WARNING] ".
func Warning(v ...interface{}) { log(warning, v...) }
// Warningf is equivalent to log.Printf, but prefixed with "[WARNING] ".
func Warningf(format string, v ...interface{}) { logf(warning, format, v...) }
// Error is equivalent to log.Print, but prefixed with "[ERROR] ".
func Error(v ...interface{}) { log(err, v...) }
// Errorf is equivalent to log.Printf, but prefixed with "[ERROR] ".
func Errorf(format string, v ...interface{}) { logf(err, format, v...) }
// Fatal is equivalent to log.Print, but prefixed with "[FATAL] ", and calling
// os.Exit(1).
func Fatal(v ...interface{}) { log(fatal, v...); os.Exit(1) }
// Fatalf is equivalent to log.Printf, but prefixed with "[FATAL] ", and calling
// os.Exit(1)
func Fatalf(format string, v ...interface{}) { logf(fatal, format, v...); os.Exit(1) }
// Discard sets the log output to /dev/null.
func Discard() { golog.SetOutput(ioutil.Discard) }
const (
debug = " [DEBUG] "
err = " [ERROR] "
fatal = " [FATAL] "
info = " [INFO] "
warning = " [WARNING] "
)