1// Copyright 2015 The etcd Authors
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package raft
16
17import (
18	"fmt"
19	"io/ioutil"
20	"log"
21	"os"
22)
23
24type Logger interface {
25	Debug(v ...interface{})
26	Debugf(format string, v ...interface{})
27
28	Error(v ...interface{})
29	Errorf(format string, v ...interface{})
30
31	Info(v ...interface{})
32	Infof(format string, v ...interface{})
33
34	Warning(v ...interface{})
35	Warningf(format string, v ...interface{})
36
37	Fatal(v ...interface{})
38	Fatalf(format string, v ...interface{})
39
40	Panic(v ...interface{})
41	Panicf(format string, v ...interface{})
42}
43
44func SetLogger(l Logger) { raftLogger = l }
45
46var (
47	defaultLogger = &DefaultLogger{Logger: log.New(os.Stderr, "raft", log.LstdFlags)}
48	discardLogger = &DefaultLogger{Logger: log.New(ioutil.Discard, "", 0)}
49	raftLogger    = Logger(defaultLogger)
50)
51
52const (
53	calldepth = 2
54)
55
56// DefaultLogger is a default implementation of the Logger interface.
57type DefaultLogger struct {
58	*log.Logger
59	debug bool
60}
61
62func (l *DefaultLogger) EnableTimestamps() {
63	l.SetFlags(l.Flags() | log.Ldate | log.Ltime)
64}
65
66func (l *DefaultLogger) EnableDebug() {
67	l.debug = true
68}
69
70func (l *DefaultLogger) Debug(v ...interface{}) {
71	if l.debug {
72		l.Output(calldepth, header("DEBUG", fmt.Sprint(v...)))
73	}
74}
75
76func (l *DefaultLogger) Debugf(format string, v ...interface{}) {
77	if l.debug {
78		l.Output(calldepth, header("DEBUG", fmt.Sprintf(format, v...)))
79	}
80}
81
82func (l *DefaultLogger) Info(v ...interface{}) {
83	l.Output(calldepth, header("INFO", fmt.Sprint(v...)))
84}
85
86func (l *DefaultLogger) Infof(format string, v ...interface{}) {
87	l.Output(calldepth, header("INFO", fmt.Sprintf(format, v...)))
88}
89
90func (l *DefaultLogger) Error(v ...interface{}) {
91	l.Output(calldepth, header("ERROR", fmt.Sprint(v...)))
92}
93
94func (l *DefaultLogger) Errorf(format string, v ...interface{}) {
95	l.Output(calldepth, header("ERROR", fmt.Sprintf(format, v...)))
96}
97
98func (l *DefaultLogger) Warning(v ...interface{}) {
99	l.Output(calldepth, header("WARN", fmt.Sprint(v...)))
100}
101
102func (l *DefaultLogger) Warningf(format string, v ...interface{}) {
103	l.Output(calldepth, header("WARN", fmt.Sprintf(format, v...)))
104}
105
106func (l *DefaultLogger) Fatal(v ...interface{}) {
107	l.Output(calldepth, header("FATAL", fmt.Sprint(v...)))
108	os.Exit(1)
109}
110
111func (l *DefaultLogger) Fatalf(format string, v ...interface{}) {
112	l.Output(calldepth, header("FATAL", fmt.Sprintf(format, v...)))
113	os.Exit(1)
114}
115
116func (l *DefaultLogger) Panic(v ...interface{}) {
117	l.Logger.Panic(v...)
118}
119
120func (l *DefaultLogger) Panicf(format string, v ...interface{}) {
121	l.Logger.Panicf(format, v...)
122}
123
124func header(lvl, msg string) string {
125	return fmt.Sprintf("%s: %s", lvl, msg)
126}
127