Refactor logging into separate package

1 files changed, 142 insertions, 0 deletions

diff --git a/logger/logger.go b/logger/logger.go
new file mode 100644
index 0000000000..2053e146bb
--- /dev/null
+++ b/logger/logger.go
@@ -0,0 +1,142 @@
+package logger
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"sync"
+)
+
+type LogLevel int
+
+const (
+	LevelDebug LogLevel = iota
+	LevelInfo
+	LevelOK
+	LevelWarn
+	LevelFatal
+	NumLevels
+)
+
+type MessageHandler func(l LogLevel, msg string)
+
+type Logger struct {
+	logger   *log.Logger
+	handlers [NumLevels][]MessageHandler
+	mut      sync.Mutex
+}
+
+var DefaultLogger = New()
+
+func New() *Logger {
+	return &Logger{
+		logger: log.New(os.Stderr, "", log.Ltime),
+	}
+}
+
+func (l *Logger) AddHandler(level LogLevel, h MessageHandler) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	l.handlers[level] = append(l.handlers[level], h)
+}
+
+func (l *Logger) SetFlags(flag int) {
+	l.logger.SetFlags(flag)
+}
+
+func (l *Logger) SetPrefix(prefix string) {
+	l.logger.SetPrefix(prefix)
+}
+
+func (l *Logger) callHandlers(level LogLevel, s string) {
+	for _, h := range l.handlers[level] {
+		h(level, s)
+	}
+}
+
+func (l *Logger) Debugln(vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintln(vals...)
+	l.logger.Output(2, "DEBUG: "+s)
+	l.callHandlers(LevelDebug, s)
+}
+
+func (l *Logger) Debugf(format string, vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintf(format, vals...)
+	l.logger.Output(2, "DEBUG: "+s)
+	l.callHandlers(LevelDebug, s)
+}
+func (l *Logger) Infoln(vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintln(vals...)
+	l.logger.Output(2, "INFO: "+s)
+	l.callHandlers(LevelInfo, s)
+}
+
+func (l *Logger) Infof(format string, vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintf(format, vals...)
+	l.logger.Output(2, "INFO: "+s)
+	l.callHandlers(LevelInfo, s)
+}
+
+func (l *Logger) Okln(vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintln(vals...)
+	l.logger.Output(2, "OK: "+s)
+	l.callHandlers(LevelOK, s)
+}
+
+func (l *Logger) Okf(format string, vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintf(format, vals...)
+	l.logger.Output(2, "OK: "+s)
+	l.callHandlers(LevelOK, s)
+}
+
+func (l *Logger) Warnln(vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintln(vals...)
+	l.logger.Output(2, "WARNING: "+s)
+	l.callHandlers(LevelWarn, s)
+}
+
+func (l *Logger) Warnf(format string, vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintf(format, vals...)
+	l.logger.Output(2, "WARNING: "+s)
+	l.callHandlers(LevelWarn, s)
+}
+
+func (l *Logger) Fatalln(vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintln(vals...)
+	l.logger.Output(2, "FATAL: "+s)
+	l.callHandlers(LevelFatal, s)
+	os.Exit(3)
+}
+
+func (l *Logger) Fatalf(format string, vals ...interface{}) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	s := fmt.Sprintf(format, vals...)
+	l.logger.Output(2, "FATAL: "+s)
+	l.callHandlers(LevelFatal, s)
+	os.Exit(3)
+}
+
+func (l *Logger) FatalErr(err error) {
+	if err != nil {
+		l.Fatalf(err.Error())
+	}
+}