323 lines
9.1 KiB
Go
323 lines
9.1 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// Package log implements a simple logging package. It defines a type, Logger,
|
|
// with methods for formatting output. It also has a predefined 'standard'
|
|
// Logger accessible through helper functions Print[f|ln], Fatal[f|ln], and
|
|
// Panic[f|ln], which are easier to use than creating a Logger manually.
|
|
// That logger writes to standard error and prints the date and time
|
|
// of each logged message.
|
|
// The Fatal functions call os.Exit(1) after writing the log message.
|
|
// The Panic functions call panic after writing the log message.
|
|
package log
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
"runtime"
|
|
"sync"
|
|
"time"
|
|
)
|
|
|
|
// These flags define which text to prefix to each log entry generated by the Logger.
|
|
const (
|
|
// Bits or'ed together to control what's printed. There is no control over the
|
|
// order they appear (the order listed here) or the format they present (as
|
|
// described in the comments). A colon appears after these items:
|
|
// 2009/0123 01:23:23.123123 /a/b/c/d.go:23: message
|
|
Ldate = 1 << iota // the date: 2009/01/23
|
|
Ltime // the time: 01:23:23
|
|
Lmicroseconds // microsecond resolution: 01:23:23.123123. assumes Ltime.
|
|
Llongfile // full file name and line number: /a/b/c/d.go:23
|
|
Lshortfile // final file name element and line number: d.go:23. overrides Llongfile
|
|
LstdFlags = Ldate | Ltime // initial values for the standard logger
|
|
)
|
|
|
|
// A Logger represents an active logging object that generates lines of
|
|
// output to an io.Writer. Each logging operation makes a single call to
|
|
// the Writer's Write method. A Logger can be used simultaneously from
|
|
// multiple goroutines; it guarantees to serialize access to the Writer.
|
|
type Logger struct {
|
|
mu sync.Mutex // ensures atomic writes; protects the following fields
|
|
prefix string // prefix to write at beginning of each line
|
|
flag int // properties
|
|
out io.Writer // destination for output
|
|
buf []byte // for accumulating text to write
|
|
}
|
|
|
|
// New creates a new Logger. The out variable sets the
|
|
// destination to which log data will be written.
|
|
// The prefix appears at the beginning of each generated log line.
|
|
// The flag argument defines the logging properties.
|
|
func New(out io.Writer, prefix string, flag int) *Logger {
|
|
return &Logger{out: out, prefix: prefix, flag: flag}
|
|
}
|
|
|
|
var std = New(os.Stderr, "", LstdFlags)
|
|
|
|
// Cheap integer to fixed-width decimal ASCII. Give a negative width to avoid zero-padding.
|
|
// Knows the buffer has capacity.
|
|
func itoa(buf *[]byte, i int, wid int) {
|
|
var u uint = uint(i)
|
|
if u == 0 && wid <= 1 {
|
|
*buf = append(*buf, '0')
|
|
return
|
|
}
|
|
|
|
// Assemble decimal in reverse order.
|
|
var b [32]byte
|
|
bp := len(b)
|
|
for ; u > 0 || wid > 0; u /= 10 {
|
|
bp--
|
|
wid--
|
|
b[bp] = byte(u%10) + '0'
|
|
}
|
|
*buf = append(*buf, b[bp:]...)
|
|
}
|
|
|
|
func (l *Logger) formatHeader(buf *[]byte, t time.Time, file string, line int) {
|
|
*buf = append(*buf, l.prefix...)
|
|
if l.flag&(Ldate|Ltime|Lmicroseconds) != 0 {
|
|
if l.flag&Ldate != 0 {
|
|
year, month, day := t.Date()
|
|
itoa(buf, year, 4)
|
|
*buf = append(*buf, '/')
|
|
itoa(buf, int(month), 2)
|
|
*buf = append(*buf, '/')
|
|
itoa(buf, day, 2)
|
|
*buf = append(*buf, ' ')
|
|
}
|
|
if l.flag&(Ltime|Lmicroseconds) != 0 {
|
|
hour, min, sec := t.Clock()
|
|
itoa(buf, hour, 2)
|
|
*buf = append(*buf, ':')
|
|
itoa(buf, min, 2)
|
|
*buf = append(*buf, ':')
|
|
itoa(buf, sec, 2)
|
|
if l.flag&Lmicroseconds != 0 {
|
|
*buf = append(*buf, '.')
|
|
itoa(buf, t.Nanosecond()/1e3, 6)
|
|
}
|
|
*buf = append(*buf, ' ')
|
|
}
|
|
}
|
|
if l.flag&(Lshortfile|Llongfile) != 0 {
|
|
if l.flag&Lshortfile != 0 {
|
|
short := file
|
|
for i := len(file) - 1; i > 0; i-- {
|
|
if file[i] == '/' {
|
|
short = file[i+1:]
|
|
break
|
|
}
|
|
}
|
|
file = short
|
|
}
|
|
*buf = append(*buf, file...)
|
|
*buf = append(*buf, ':')
|
|
itoa(buf, line, -1)
|
|
*buf = append(*buf, ": "...)
|
|
}
|
|
}
|
|
|
|
// Output writes the output for a logging event. The string s contains
|
|
// the text to print after the prefix specified by the flags of the
|
|
// Logger. A newline is appended if the last character of s is not
|
|
// already a newline. Calldepth is used to recover the PC and is
|
|
// provided for generality, although at the moment on all pre-defined
|
|
// paths it will be 2.
|
|
func (l *Logger) Output(calldepth int, s string) error {
|
|
now := time.Now() // get this early.
|
|
var file string
|
|
var line int
|
|
l.mu.Lock()
|
|
defer l.mu.Unlock()
|
|
if l.flag&(Lshortfile|Llongfile) != 0 {
|
|
// release lock while getting caller info - it's expensive.
|
|
l.mu.Unlock()
|
|
var ok bool
|
|
_, file, line, ok = runtime.Caller(calldepth)
|
|
if !ok {
|
|
file = "???"
|
|
line = 0
|
|
}
|
|
l.mu.Lock()
|
|
}
|
|
l.buf = l.buf[:0]
|
|
l.formatHeader(&l.buf, now, file, line)
|
|
l.buf = append(l.buf, s...)
|
|
if len(s) > 0 && s[len(s)-1] != '\n' {
|
|
l.buf = append(l.buf, '\n')
|
|
}
|
|
_, err := l.out.Write(l.buf)
|
|
return err
|
|
}
|
|
|
|
// Printf calls l.Output to print to the logger.
|
|
// Arguments are handled in the manner of fmt.Printf.
|
|
func (l *Logger) Printf(format string, v ...interface{}) {
|
|
l.Output(2, fmt.Sprintf(format, v...))
|
|
}
|
|
|
|
// Print calls l.Output to print to the logger.
|
|
// Arguments are handled in the manner of fmt.Print.
|
|
func (l *Logger) Print(v ...interface{}) { l.Output(2, fmt.Sprint(v...)) }
|
|
|
|
// Println calls l.Output to print to the logger.
|
|
// Arguments are handled in the manner of fmt.Println.
|
|
func (l *Logger) Println(v ...interface{}) { l.Output(2, fmt.Sprintln(v...)) }
|
|
|
|
// Fatal is equivalent to l.Print() followed by a call to os.Exit(1).
|
|
func (l *Logger) Fatal(v ...interface{}) {
|
|
l.Output(2, fmt.Sprint(v...))
|
|
os.Exit(1)
|
|
}
|
|
|
|
// Fatalf is equivalent to l.Printf() followed by a call to os.Exit(1).
|
|
func (l *Logger) Fatalf(format string, v ...interface{}) {
|
|
l.Output(2, fmt.Sprintf(format, v...))
|
|
os.Exit(1)
|
|
}
|
|
|
|
// Fatalln is equivalent to l.Println() followed by a call to os.Exit(1).
|
|
func (l *Logger) Fatalln(v ...interface{}) {
|
|
l.Output(2, fmt.Sprintln(v...))
|
|
os.Exit(1)
|
|
}
|
|
|
|
// Panic is equivalent to l.Print() followed by a call to panic().
|
|
func (l *Logger) Panic(v ...interface{}) {
|
|
s := fmt.Sprint(v...)
|
|
l.Output(2, s)
|
|
panic(s)
|
|
}
|
|
|
|
// Panicf is equivalent to l.Printf() followed by a call to panic().
|
|
func (l *Logger) Panicf(format string, v ...interface{}) {
|
|
s := fmt.Sprintf(format, v...)
|
|
l.Output(2, s)
|
|
panic(s)
|
|
}
|
|
|
|
// Panicln is equivalent to l.Println() followed by a call to panic().
|
|
func (l *Logger) Panicln(v ...interface{}) {
|
|
s := fmt.Sprintln(v...)
|
|
l.Output(2, s)
|
|
panic(s)
|
|
}
|
|
|
|
// Flags returns the output flags for the logger.
|
|
func (l *Logger) Flags() int {
|
|
l.mu.Lock()
|
|
defer l.mu.Unlock()
|
|
return l.flag
|
|
}
|
|
|
|
// SetFlags sets the output flags for the logger.
|
|
func (l *Logger) SetFlags(flag int) {
|
|
l.mu.Lock()
|
|
defer l.mu.Unlock()
|
|
l.flag = flag
|
|
}
|
|
|
|
// Prefix returns the output prefix for the logger.
|
|
func (l *Logger) Prefix() string {
|
|
l.mu.Lock()
|
|
defer l.mu.Unlock()
|
|
return l.prefix
|
|
}
|
|
|
|
// SetPrefix sets the output prefix for the logger.
|
|
func (l *Logger) SetPrefix(prefix string) {
|
|
l.mu.Lock()
|
|
defer l.mu.Unlock()
|
|
l.prefix = prefix
|
|
}
|
|
|
|
// SetOutput sets the output destination for the standard logger.
|
|
func SetOutput(w io.Writer) {
|
|
std.mu.Lock()
|
|
defer std.mu.Unlock()
|
|
std.out = w
|
|
}
|
|
|
|
// Flags returns the output flags for the standard logger.
|
|
func Flags() int {
|
|
return std.Flags()
|
|
}
|
|
|
|
// SetFlags sets the output flags for the standard logger.
|
|
func SetFlags(flag int) {
|
|
std.SetFlags(flag)
|
|
}
|
|
|
|
// Prefix returns the output prefix for the standard logger.
|
|
func Prefix() string {
|
|
return std.Prefix()
|
|
}
|
|
|
|
// SetPrefix sets the output prefix for the standard logger.
|
|
func SetPrefix(prefix string) {
|
|
std.SetPrefix(prefix)
|
|
}
|
|
|
|
// These functions write to the standard logger.
|
|
|
|
// Print calls Output to print to the standard logger.
|
|
// Arguments are handled in the manner of fmt.Print.
|
|
func Print(v ...interface{}) {
|
|
std.Output(2, fmt.Sprint(v...))
|
|
}
|
|
|
|
// Printf calls Output to print to the standard logger.
|
|
// Arguments are handled in the manner of fmt.Printf.
|
|
func Printf(format string, v ...interface{}) {
|
|
std.Output(2, fmt.Sprintf(format, v...))
|
|
}
|
|
|
|
// Println calls Output to print to the standard logger.
|
|
// Arguments are handled in the manner of fmt.Println.
|
|
func Println(v ...interface{}) {
|
|
std.Output(2, fmt.Sprintln(v...))
|
|
}
|
|
|
|
// Fatal is equivalent to Print() followed by a call to os.Exit(1).
|
|
func Fatal(v ...interface{}) {
|
|
std.Output(2, fmt.Sprint(v...))
|
|
os.Exit(1)
|
|
}
|
|
|
|
// Fatalf is equivalent to Printf() followed by a call to os.Exit(1).
|
|
func Fatalf(format string, v ...interface{}) {
|
|
std.Output(2, fmt.Sprintf(format, v...))
|
|
os.Exit(1)
|
|
}
|
|
|
|
// Fatalln is equivalent to Println() followed by a call to os.Exit(1).
|
|
func Fatalln(v ...interface{}) {
|
|
std.Output(2, fmt.Sprintln(v...))
|
|
os.Exit(1)
|
|
}
|
|
|
|
// Panic is equivalent to Print() followed by a call to panic().
|
|
func Panic(v ...interface{}) {
|
|
s := fmt.Sprint(v...)
|
|
std.Output(2, s)
|
|
panic(s)
|
|
}
|
|
|
|
// Panicf is equivalent to Printf() followed by a call to panic().
|
|
func Panicf(format string, v ...interface{}) {
|
|
s := fmt.Sprintf(format, v...)
|
|
std.Output(2, s)
|
|
panic(s)
|
|
}
|
|
|
|
// Panicln is equivalent to Println() followed by a call to panic().
|
|
func Panicln(v ...interface{}) {
|
|
s := fmt.Sprintln(v...)
|
|
std.Output(2, s)
|
|
panic(s)
|
|
}
|