Commit 806d00fc authored by Rob Pike's avatar Rob Pike

add start to a logging package.

R=rsc
DELTA=205  (205 added, 0 deleted, 0 changed)
OCL=23448
CL=23478
parent 3338c71f
......@@ -27,6 +27,7 @@ DIRS=\
FILES=\
bufio\
flag\
log\
malloc\
once\
rand\
......@@ -91,6 +92,7 @@ test: test.files
bignum.6: fmt.dirinstall
bufio.6: io.dirinstall os.dirinstall
flag.6: fmt.dirinstall
log.6: fmt.dirinstall io.dirinstall os.dirinstall time.dirinstall
testing.6: flag.install fmt.dirinstall
strings.6: utf8.install
......
// 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.
// Rudimentary logging package. Defines a type, Logger, with simple
// methods for formatting output to one or two destinations. Also has
// predefined Loggers accessible through helper functions Stdout[f],
// Stderr[f], Exit[f], and Crash[f].
// Exit exits when written to.
// Crash causes a crash when written to.
package log
import (
"fmt";
"io";
"os";
"time";
)
// Lshortname can be or'd in to cause only the last element of the file name to be printed.
const (
Lok = iota;
Lexit; // terminate execution when written
Lcrash; // crash (panic) when written
Lshortname = 1 << 5;
)
type Logger struct {
out0 io.Write;
out1 io.Write;
flag int;
}
func NewLogger(out0, out1 io.Write, flag int) *Logger {
return &Logger{out0, out1, flag}
}
var (
stdout = NewLogger(os.Stdout, nil, Lok);
stderr = NewLogger(os.Stderr, nil, Lok);
exit = NewLogger(os.Stderr, nil, Lexit);
crash = NewLogger(os.Stderr, nil, Lcrash);
)
func timestamp(ns int64) string {
t := time.SecondsToLocalTime(ns/1e9);
// why are time fields private?
s := t.RFC1123();
return s[5:12] + s[17:25]; // TODO(r): placeholder. this gives "24 Jan 15:50:18"
}
var shortnames = make(map[string] string) // cache of short names to avoid allocation.
// The calldepth is provided for generality, although at the moment on all paths it will be 2.
func (l *Logger) output(calldepth int, s string) {
now := time.Nanoseconds(); // get this early.
newline := "\n";
if len(s) > 0 && s[len(s)-1] == '\n' {
newline = ""
}
pc, file, line, ok := sys.Caller(calldepth);
if ok {
if l.flag & Lshortname == Lshortname {
short, ok := shortnames[file];
if !ok {
short = file;
for i := len(file) - 1; i > 0; i-- {
if file[i] == '/' {
short = file[i+1:len(file)];
shortnames[file] = short;
break;
}
}
}
file = short;
}
} else {
file = "???";
line = 0;
}
s = fmt.Sprintf("%s %s:%d: %s%s", timestamp(now), file, line, s, newline);
io.WriteString(l.out0, s);
if l.out1 != nil {
io.WriteString(l.out1, s);
}
switch l.flag & ^Lshortname {
case Lcrash:
panic("log: fatal error");
case Lexit:
sys.Exit(1);
}
}
// Basic methods on Logger, analogous to Printf and Print
func (l *Logger) Logf(format string, v ...) {
l.output(2, fmt.Sprintf(format, v))
}
func (l *Logger) Log(v ...) {
l.output(2, fmt.Sprintln(v))
}
// Helper functions for lightweight simple logging to predefined Loggers.
func Stdout(v ...) {
stdout.output(2, fmt.Sprint(v))
}
func Stderr(v ...) {
stdout.output(2, fmt.Sprintln(v))
}
func Stdoutf(format string, v ...) {
stdout.output(2, fmt.Sprintf(format, v))
}
func Stderrf(format string, v ...) {
stderr.output(2, fmt.Sprintf(format, v))
}
func Exit(v ...) {
exit.output(2, fmt.Sprintln(v))
}
func Exitf(format string, v ...) {
exit.output(2, fmt.Sprintf(format, v))
}
func Crash(v ...) {
crash.output(2, fmt.Sprintln(v))
}
func Crashf(format string, v ...) {
crash.output(2, fmt.Sprintf(format, v))
}
// 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
// These tests are too simple.
import (
"bufio";
"log";
"os";
"testing";
)
func test(t *testing.T, flag int, expect string) {
fd0, fd1, err1 := os.Pipe();
if err1 != nil {
t.Error("pipe", err1);
}
buf, err2 := bufio.NewBufRead(fd0);
if err2 != nil {
t.Error("bufio.NewBufRead", err2);
}
l := NewLogger(fd1, nil, flag);
l.Log("hello", 23, "world"); /// the line number of this line needs to be placed in the expect strings
line, err3 := buf.ReadLineString('\n', false);
if line[len(line)-len(expect):len(line)] != expect {
t.Error("log output should be ...", expect, "; is " , line);
}
t.Log(line);
fd0.Close();
fd1.Close();
}
func TestRegularLog(t *testing.T) {
test(t, Lok, "/go/src/lib/log_test.go:25: hello 23 world");
}
func TestShortNameLog(t *testing.T) {
test(t, Lok|Lshortname, " log_test.go:25: hello 23 world")
}
func testFormatted(t *testing.T, flag int, expect string) {
fd0, fd1, err1 := os.Pipe();
if err1 != nil {
t.Error("pipe", err1);
}
buf, err2 := bufio.NewBufRead(fd0);
if err2 != nil {
t.Error("bufio.NewBufRead", err2);
}
l := NewLogger(fd1, nil, flag);
l.Logf("hello %d world", 23); /// the line number of this line needs to be placed in the expect strings
line, err3 := buf.ReadLineString('\n', false);
if line[len(line)-len(expect):len(line)] != expect {
t.Error("log output should be ...", expect, "; is " , line);
}
t.Log(line);
fd0.Close();
fd1.Close();
}
func TestRegularLogFormatted(t *testing.T) {
testFormatted(t, Lok, "/go/src/lib/log_test.go:53: hello 23 world");
}
func TestShortNameLogFormatted(t *testing.T) {
testFormatted(t, Lok|Lshortname, " log_test.go:53: hello 23 world")
}
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