458 lines
13 KiB
Go
458 lines
13 KiB
Go
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// Copyright 2014-2017 Ulrich Kunitz. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Package xlog provides a simple logging package that allows to disable
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// certain message categories. It defines a type, Logger, with multiple
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// methods for formatting output. The package has also a predefined
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// 'standard' Logger accessible through helper function Print[f|ln],
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// Fatal[f|ln], Panic[f|ln], Warn[f|ln], Print[f|ln] and Debug[f|ln]
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// that are easier to use then creating a Logger manually. That logger
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// writes to standard error and prints the date and time of each logged
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// message, which can be configured using the function SetFlags.
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//
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// The Fatal functions call os.Exit(1) after the message is output
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// unless not suppressed by the flags. The Panic functions call panic
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// after the writing the log message unless suppressed.
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package xlog
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import (
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"fmt"
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"io"
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"os"
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"runtime"
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"sync"
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"time"
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)
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// The flags define what information is prefixed to each log entry
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// generated by the Logger. The Lno* versions allow the suppression of
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// specific output. The bits are or'ed together to control what will be
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// printed. There is no control over the order of the items printed and
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// the format. The full format is:
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//
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// 2009-01-23 01:23:23.123123 /a/b/c/d.go:23: message
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//
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const (
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Ldate = 1 << iota // the date: 2009-01-23
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Ltime // the time: 01:23:23
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Lmicroseconds // microsecond resolution: 01:23:23.123123
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Llongfile // full file name and line number: /a/b/c/d.go:23
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Lshortfile // final file name element and line number: d.go:23
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Lnopanic // suppresses output from Panic[f|ln] but not the panic call
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Lnofatal // suppresses output from Fatal[f|ln] but not the exit
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Lnowarn // suppresses output from Warn[f|ln]
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Lnoprint // suppresses output from Print[f|ln]
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Lnodebug // suppresses output from Debug[f|ln]
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// initial values for the standard logger
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Lstdflags = Ldate | Ltime | Lnodebug
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)
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// A Logger represents an active logging object that generates lines of
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// output to an io.Writer. Each logging operation if not suppressed
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// makes a single call to the Writer's Write method. A Logger can be
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// used simultaneously from multiple goroutines; it guarantees to
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// serialize access to the Writer.
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type Logger struct {
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mu sync.Mutex // ensures atomic writes; and protects the following
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// fields
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prefix string // prefix to write at beginning of each line
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flag int // properties
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out io.Writer // destination for output
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buf []byte // for accumulating text to write
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}
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// New creates a new Logger. The out argument sets the destination to
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// which the log output will be written. The prefix appears at the
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// beginning of each log line. The flag argument defines the logging
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// properties.
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func New(out io.Writer, prefix string, flag int) *Logger {
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return &Logger{out: out, prefix: prefix, flag: flag}
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}
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// std is the standard logger used by the package scope functions.
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var std = New(os.Stderr, "", Lstdflags)
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// itoa converts the integer to ASCII. A negative widths will avoid
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// zero-padding. The function supports only non-negative integers.
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func itoa(buf *[]byte, i int, wid int) {
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var u = uint(i)
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if u == 0 && wid <= 1 {
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*buf = append(*buf, '0')
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return
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}
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var b [32]byte
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bp := len(b)
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for ; u > 0 || wid > 0; u /= 10 {
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bp--
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wid--
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b[bp] = byte(u%10) + '0'
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}
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*buf = append(*buf, b[bp:]...)
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}
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// formatHeader puts the header into the buf field of the buffer.
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func (l *Logger) formatHeader(t time.Time, file string, line int) {
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l.buf = append(l.buf, l.prefix...)
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if l.flag&(Ldate|Ltime|Lmicroseconds) != 0 {
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if l.flag&Ldate != 0 {
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year, month, day := t.Date()
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itoa(&l.buf, year, 4)
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l.buf = append(l.buf, '-')
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itoa(&l.buf, int(month), 2)
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l.buf = append(l.buf, '-')
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itoa(&l.buf, day, 2)
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l.buf = append(l.buf, ' ')
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}
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if l.flag&(Ltime|Lmicroseconds) != 0 {
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hour, min, sec := t.Clock()
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itoa(&l.buf, hour, 2)
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l.buf = append(l.buf, ':')
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itoa(&l.buf, min, 2)
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l.buf = append(l.buf, ':')
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itoa(&l.buf, sec, 2)
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if l.flag&Lmicroseconds != 0 {
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l.buf = append(l.buf, '.')
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itoa(&l.buf, t.Nanosecond()/1e3, 6)
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}
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l.buf = append(l.buf, ' ')
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}
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}
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if l.flag&(Lshortfile|Llongfile) != 0 {
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if l.flag&Lshortfile != 0 {
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short := file
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for i := len(file) - 1; i > 0; i-- {
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if file[i] == '/' {
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short = file[i+1:]
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break
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}
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}
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file = short
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}
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l.buf = append(l.buf, file...)
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l.buf = append(l.buf, ':')
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itoa(&l.buf, line, -1)
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l.buf = append(l.buf, ": "...)
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}
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}
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func (l *Logger) output(calldepth int, now time.Time, s string) error {
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var file string
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var line int
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if l.flag&(Lshortfile|Llongfile) != 0 {
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l.mu.Unlock()
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var ok bool
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_, file, line, ok = runtime.Caller(calldepth)
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if !ok {
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file = "???"
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line = 0
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}
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l.mu.Lock()
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}
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l.buf = l.buf[:0]
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l.formatHeader(now, file, line)
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l.buf = append(l.buf, s...)
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if len(s) == 0 || s[len(s)-1] != '\n' {
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l.buf = append(l.buf, '\n')
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}
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_, err := l.out.Write(l.buf)
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return err
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}
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// Output writes the string s with the header controlled by the flags to
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// the l.out writer. A newline will be appended if s doesn't end in a
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// newline. Calldepth is used to recover the PC, although all current
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// calls of Output use the call depth 2. Access to the function is serialized.
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func (l *Logger) Output(calldepth, noflag int, v ...interface{}) error {
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now := time.Now()
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l.mu.Lock()
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defer l.mu.Unlock()
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if l.flag&noflag != 0 {
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return nil
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}
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s := fmt.Sprint(v...)
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return l.output(calldepth+1, now, s)
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}
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// Outputf works like output but formats the output like Printf.
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func (l *Logger) Outputf(calldepth int, noflag int, format string, v ...interface{}) error {
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now := time.Now()
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l.mu.Lock()
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defer l.mu.Unlock()
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if l.flag&noflag != 0 {
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return nil
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}
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s := fmt.Sprintf(format, v...)
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return l.output(calldepth+1, now, s)
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}
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// Outputln works like output but formats the output like Println.
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func (l *Logger) Outputln(calldepth int, noflag int, v ...interface{}) error {
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now := time.Now()
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l.mu.Lock()
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defer l.mu.Unlock()
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if l.flag&noflag != 0 {
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return nil
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}
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s := fmt.Sprintln(v...)
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return l.output(calldepth+1, now, s)
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}
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// Panic prints the message like Print and calls panic. The printing
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// might be suppressed by the flag Lnopanic.
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func (l *Logger) Panic(v ...interface{}) {
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l.Output(2, Lnopanic, v...)
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s := fmt.Sprint(v...)
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panic(s)
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}
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// Panic prints the message like Print and calls panic. The printing
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// might be suppressed by the flag Lnopanic.
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func Panic(v ...interface{}) {
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std.Output(2, Lnopanic, v...)
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s := fmt.Sprint(v...)
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panic(s)
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}
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// Panicf prints the message like Printf and calls panic. The printing
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// might be suppressed by the flag Lnopanic.
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func (l *Logger) Panicf(format string, v ...interface{}) {
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l.Outputf(2, Lnopanic, format, v...)
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s := fmt.Sprintf(format, v...)
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panic(s)
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}
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// Panicf prints the message like Printf and calls panic. The printing
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// might be suppressed by the flag Lnopanic.
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func Panicf(format string, v ...interface{}) {
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std.Outputf(2, Lnopanic, format, v...)
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s := fmt.Sprintf(format, v...)
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panic(s)
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}
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// Panicln prints the message like Println and calls panic. The printing
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// might be suppressed by the flag Lnopanic.
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func (l *Logger) Panicln(v ...interface{}) {
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l.Outputln(2, Lnopanic, v...)
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s := fmt.Sprintln(v...)
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panic(s)
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}
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// Panicln prints the message like Println and calls panic. The printing
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// might be suppressed by the flag Lnopanic.
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func Panicln(v ...interface{}) {
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std.Outputln(2, Lnopanic, v...)
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s := fmt.Sprintln(v...)
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panic(s)
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}
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// Fatal prints the message like Print and calls os.Exit(1). The
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// printing might be suppressed by the flag Lnofatal.
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func (l *Logger) Fatal(v ...interface{}) {
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l.Output(2, Lnofatal, v...)
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os.Exit(1)
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}
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// Fatal prints the message like Print and calls os.Exit(1). The
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// printing might be suppressed by the flag Lnofatal.
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func Fatal(v ...interface{}) {
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std.Output(2, Lnofatal, v...)
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os.Exit(1)
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}
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// Fatalf prints the message like Printf and calls os.Exit(1). The
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// printing might be suppressed by the flag Lnofatal.
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func (l *Logger) Fatalf(format string, v ...interface{}) {
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l.Outputf(2, Lnofatal, format, v...)
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os.Exit(1)
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}
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// Fatalf prints the message like Printf and calls os.Exit(1). The
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// printing might be suppressed by the flag Lnofatal.
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func Fatalf(format string, v ...interface{}) {
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std.Outputf(2, Lnofatal, format, v...)
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os.Exit(1)
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}
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// Fatalln prints the message like Println and calls os.Exit(1). The
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// printing might be suppressed by the flag Lnofatal.
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func (l *Logger) Fatalln(format string, v ...interface{}) {
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l.Outputln(2, Lnofatal, v...)
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os.Exit(1)
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}
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// Fatalln prints the message like Println and calls os.Exit(1). The
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// printing might be suppressed by the flag Lnofatal.
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func Fatalln(format string, v ...interface{}) {
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std.Outputln(2, Lnofatal, v...)
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os.Exit(1)
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}
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// Warn prints the message like Print. The printing might be suppressed
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// by the flag Lnowarn.
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func (l *Logger) Warn(v ...interface{}) {
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l.Output(2, Lnowarn, v...)
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}
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// Warn prints the message like Print. The printing might be suppressed
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// by the flag Lnowarn.
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func Warn(v ...interface{}) {
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std.Output(2, Lnowarn, v...)
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}
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// Warnf prints the message like Printf. The printing might be suppressed
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// by the flag Lnowarn.
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func (l *Logger) Warnf(format string, v ...interface{}) {
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l.Outputf(2, Lnowarn, format, v...)
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}
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// Warnf prints the message like Printf. The printing might be suppressed
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// by the flag Lnowarn.
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func Warnf(format string, v ...interface{}) {
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std.Outputf(2, Lnowarn, format, v...)
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}
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// Warnln prints the message like Println. The printing might be suppressed
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// by the flag Lnowarn.
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func (l *Logger) Warnln(v ...interface{}) {
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l.Outputln(2, Lnowarn, v...)
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}
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// Warnln prints the message like Println. The printing might be suppressed
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// by the flag Lnowarn.
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func Warnln(v ...interface{}) {
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std.Outputln(2, Lnowarn, v...)
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}
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// Print prints the message like fmt.Print. The printing might be suppressed
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// by the flag Lnoprint.
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func (l *Logger) Print(v ...interface{}) {
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l.Output(2, Lnoprint, v...)
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}
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// Print prints the message like fmt.Print. The printing might be suppressed
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// by the flag Lnoprint.
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func Print(v ...interface{}) {
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std.Output(2, Lnoprint, v...)
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}
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// Printf prints the message like fmt.Printf. The printing might be suppressed
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// by the flag Lnoprint.
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func (l *Logger) Printf(format string, v ...interface{}) {
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l.Outputf(2, Lnoprint, format, v...)
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}
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// Printf prints the message like fmt.Printf. The printing might be suppressed
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// by the flag Lnoprint.
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func Printf(format string, v ...interface{}) {
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std.Outputf(2, Lnoprint, format, v...)
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}
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// Println prints the message like fmt.Println. The printing might be
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// suppressed by the flag Lnoprint.
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func (l *Logger) Println(v ...interface{}) {
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l.Outputln(2, Lnoprint, v...)
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}
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// Println prints the message like fmt.Println. The printing might be
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// suppressed by the flag Lnoprint.
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func Println(v ...interface{}) {
|
||
|
|
std.Outputln(2, Lnoprint, v...)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Debug prints the message like Print. The printing might be suppressed
|
||
|
|
// by the flag Lnodebug.
|
||
|
|
func (l *Logger) Debug(v ...interface{}) {
|
||
|
|
l.Output(2, Lnodebug, v...)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Debug prints the message like Print. The printing might be suppressed
|
||
|
|
// by the flag Lnodebug.
|
||
|
|
func Debug(v ...interface{}) {
|
||
|
|
std.Output(2, Lnodebug, v...)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Debugf prints the message like Printf. The printing might be suppressed
|
||
|
|
// by the flag Lnodebug.
|
||
|
|
func (l *Logger) Debugf(format string, v ...interface{}) {
|
||
|
|
l.Outputf(2, Lnodebug, format, v...)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Debugf prints the message like Printf. The printing might be suppressed
|
||
|
|
// by the flag Lnodebug.
|
||
|
|
func Debugf(format string, v ...interface{}) {
|
||
|
|
std.Outputf(2, Lnodebug, format, v...)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Debugln prints the message like Println. The printing might be suppressed
|
||
|
|
// by the flag Lnodebug.
|
||
|
|
func (l *Logger) Debugln(v ...interface{}) {
|
||
|
|
l.Outputln(2, Lnodebug, v...)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Debugln prints the message like Println. The printing might be suppressed
|
||
|
|
// by the flag Lnodebug.
|
||
|
|
func Debugln(v ...interface{}) {
|
||
|
|
std.Outputln(2, Lnodebug, v...)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Flags returns the current flags used by the logger.
|
||
|
|
func (l *Logger) Flags() int {
|
||
|
|
l.mu.Lock()
|
||
|
|
defer l.mu.Unlock()
|
||
|
|
return l.flag
|
||
|
|
}
|
||
|
|
|
||
|
|
// Flags returns the current flags used by the standard logger.
|
||
|
|
func Flags() int {
|
||
|
|
return std.Flags()
|
||
|
|
}
|
||
|
|
|
||
|
|
// SetFlags sets the flags of the logger.
|
||
|
|
func (l *Logger) SetFlags(flag int) {
|
||
|
|
l.mu.Lock()
|
||
|
|
defer l.mu.Unlock()
|
||
|
|
l.flag = flag
|
||
|
|
}
|
||
|
|
|
||
|
|
// SetFlags sets the flags for the standard logger.
|
||
|
|
func SetFlags(flag int) {
|
||
|
|
std.SetFlags(flag)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Prefix returns the prefix used by the logger.
|
||
|
|
func (l *Logger) Prefix() string {
|
||
|
|
l.mu.Lock()
|
||
|
|
defer l.mu.Unlock()
|
||
|
|
return l.prefix
|
||
|
|
}
|
||
|
|
|
||
|
|
// Prefix returns the prefix used by the standard logger of the package.
|
||
|
|
func Prefix() string {
|
||
|
|
return std.Prefix()
|
||
|
|
}
|
||
|
|
|
||
|
|
// SetPrefix sets the prefix for the logger.
|
||
|
|
func (l *Logger) SetPrefix(prefix string) {
|
||
|
|
l.mu.Lock()
|
||
|
|
defer l.mu.Unlock()
|
||
|
|
l.prefix = prefix
|
||
|
|
}
|
||
|
|
|
||
|
|
// SetPrefix sets the prefix of the standard logger of the package.
|
||
|
|
func SetPrefix(prefix string) {
|
||
|
|
std.SetPrefix(prefix)
|
||
|
|
}
|
||
|
|
|
||
|
|
// SetOutput sets the output of the logger.
|
||
|
|
func (l *Logger) SetOutput(w io.Writer) {
|
||
|
|
l.mu.Lock()
|
||
|
|
defer l.mu.Unlock()
|
||
|
|
l.out = w
|
||
|
|
}
|
||
|
|
|
||
|
|
// SetOutput sets the output for the standard logger of the package.
|
||
|
|
func SetOutput(w io.Writer) {
|
||
|
|
std.SetOutput(w)
|
||
|
|
}
|