Commit 381ac432 authored by Tim Hockin's avatar Tim Hockin

bump(github.com/golang/glog): d1c4472bf2efd3826f2b5bdcc02d8416798d678c

parent b2a7d197
glog
====
Leveled execution logs for Go.
This is an efficient pure Go implementation of leveled logs in the
manner of the open source C++ package
http://code.google.com/p/google-glog
By binding methods to booleans it is possible to use the log package
without paying the expense of evaluating the arguments to the log.
Through the -vmodule flag, the package also provides fine-grained
control over logging at the file level.
The comment from glog.go introduces the ideas:
Package glog implements logging analogous to the Google-internal
C++ INFO/ERROR/V setup. It provides functions Info, Warning,
Error, Fatal, plus formatting variants such as Infof. It
also provides V-style logging controlled by the -v and
-vmodule=file=2 flags.
Basic examples:
glog.Info("Prepare to repel boarders")
glog.Fatalf("Initialization failed: %s", err)
See the documentation for the V function for an explanation
of these examples:
if glog.V(2) {
glog.Info("Starting transaction...")
}
glog.V(2).Infoln("Processed", nItems, "elements")
The repository contains an open source version of the log package
used inside Google. The master copy of the source lives inside
Google, not here. The code in this repo is for export only and is not itself
under development. Feature requests will be ignored.
Send bug reports to golang-nuts@googlegroups.com.
// Go support for leveled logs, analogous to https://code.google.com/p/google-glog/
//
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// File I/O for logs.
package glog
import (
"errors"
"flag"
"fmt"
"os"
"os/user"
"path/filepath"
"strings"
"sync"
"time"
)
// MaxSize is the maximum size of a log file in bytes.
var MaxSize uint64 = 1024 * 1024 * 1800
// logDirs lists the candidate directories for new log files.
var logDirs []string
// If non-empty, overrides the choice of directory in which to write logs.
// See createLogDirs for the full list of possible destinations.
var logDir = flag.String("log_dir", "", "If non-empty, write log files in this directory")
func createLogDirs() {
if *logDir != "" {
logDirs = append(logDirs, *logDir)
}
logDirs = append(logDirs, os.TempDir())
}
var (
pid = os.Getpid()
program = filepath.Base(os.Args[0])
host = "unknownhost"
userName = "unknownuser"
)
func init() {
h, err := os.Hostname()
if err == nil {
host = shortHostname(h)
}
current, err := user.Current()
if err == nil {
userName = current.Username
}
// Sanitize userName since it may contain filepath separators on Windows.
userName = strings.Replace(userName, `\`, "_", -1)
}
// shortHostname returns its argument, truncating at the first period.
// For instance, given "www.google.com" it returns "www".
func shortHostname(hostname string) string {
if i := strings.Index(hostname, "."); i >= 0 {
return hostname[:i]
}
return hostname
}
// logName returns a new log file name containing tag, with start time t, and
// the name for the symlink for tag.
func logName(tag string, t time.Time) (name, link string) {
name = fmt.Sprintf("%s.%s.%s.log.%s.%04d%02d%02d-%02d%02d%02d.%d",
program,
host,
userName,
tag,
t.Year(),
t.Month(),
t.Day(),
t.Hour(),
t.Minute(),
t.Second(),
pid)
return name, program + "." + tag
}
var onceLogDirs sync.Once
// create creates a new log file and returns the file and its filename, which
// contains tag ("INFO", "FATAL", etc.) and t. If the file is created
// successfully, create also attempts to update the symlink for that tag, ignoring
// errors.
func create(tag string, t time.Time) (f *os.File, filename string, err error) {
onceLogDirs.Do(createLogDirs)
if len(logDirs) == 0 {
return nil, "", errors.New("log: no log dirs")
}
name, link := logName(tag, t)
var lastErr error
for _, dir := range logDirs {
fname := filepath.Join(dir, name)
f, err := os.Create(fname)
if err == nil {
symlink := filepath.Join(dir, link)
os.Remove(symlink) // ignore err
os.Symlink(name, symlink) // ignore err
return f, fname, nil
}
lastErr = err
}
return nil, "", fmt.Errorf("log: cannot create log: %v", lastErr)
}
// Go support for leveled logs, analogous to https://code.google.com/p/google-glog/
//
// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package glog
import (
"bytes"
"fmt"
"path/filepath"
"runtime"
"strings"
"testing"
"time"
)
// Test that shortHostname works as advertised.
func TestShortHostname(t *testing.T) {
for hostname, expect := range map[string]string{
"": "",
"host": "host",
"host.google.com": "host",
} {
if got := shortHostname(hostname); expect != got {
t.Errorf("shortHostname(%q): expected %q, got %q", hostname, expect, got)
}
}
}
// flushBuffer wraps a bytes.Buffer to satisfy flushSyncWriter.
type flushBuffer struct {
bytes.Buffer
}
func (f *flushBuffer) Flush() error {
return nil
}
func (f *flushBuffer) Sync() error {
return nil
}
// swap sets the log writers and returns the old array.
func (l *loggingT) swap(writers [numSeverity]flushSyncWriter) (old [numSeverity]flushSyncWriter) {
l.mu.Lock()
defer l.mu.Unlock()
old = l.file
for i, w := range writers {
logging.file[i] = w
}
return
}
// newBuffers sets the log writers to all new byte buffers and returns the old array.
func (l *loggingT) newBuffers() [numSeverity]flushSyncWriter {
return l.swap([numSeverity]flushSyncWriter{new(flushBuffer), new(flushBuffer), new(flushBuffer), new(flushBuffer)})
}
// contents returns the specified log value as a string.
func contents(s severity) string {
return logging.file[s].(*flushBuffer).String()
}
// contains reports whether the string is contained in the log.
func contains(s severity, str string, t *testing.T) bool {
return strings.Contains(contents(s), str)
}
// setFlags configures the logging flags how the test expects them.
func setFlags() {
logging.toStderr = false
}
// Test that Info works as advertised.
func TestInfo(t *testing.T) {
setFlags()
defer logging.swap(logging.newBuffers())
Info("test")
if !contains(infoLog, "I", t) {
t.Errorf("Info has wrong character: %q", contents(infoLog))
}
if !contains(infoLog, "test", t) {
t.Error("Info failed")
}
}
// Test that the header has the correct format.
func TestHeader(t *testing.T) {
setFlags()
defer logging.swap(logging.newBuffers())
defer func(previous func() time.Time) { timeNow = previous }(timeNow)
timeNow = func() time.Time {
return time.Date(2006, 1, 2, 15, 4, 5, .678901e9, time.Local)
}
Info("test")
var line, pid int
n, err := fmt.Sscanf(contents(infoLog), "I0102 15:04:05.678901 %d glog_test.go:%d] test\n", &pid, &line)
if n != 2 || err != nil {
t.Errorf("log format error: %d elements, error %s:\n%s", n, err, contents(infoLog))
}
}
// Test that an Error log goes to Warning and Info.
// Even in the Info log, the source character will be E, so the data should
// all be identical.
func TestError(t *testing.T) {
setFlags()
defer logging.swap(logging.newBuffers())
Error("test")
if !contains(errorLog, "E", t) {
t.Errorf("Error has wrong character: %q", contents(errorLog))
}
if !contains(errorLog, "test", t) {
t.Error("Error failed")
}
str := contents(errorLog)
if !contains(warningLog, str, t) {
t.Error("Warning failed")
}
if !contains(infoLog, str, t) {
t.Error("Info failed")
}
}
// Test that a Warning log goes to Info.
// Even in the Info log, the source character will be W, so the data should
// all be identical.
func TestWarning(t *testing.T) {
setFlags()
defer logging.swap(logging.newBuffers())
Warning("test")
if !contains(warningLog, "W", t) {
t.Errorf("Warning has wrong character: %q", contents(warningLog))
}
if !contains(warningLog, "test", t) {
t.Error("Warning failed")
}
str := contents(warningLog)
if !contains(infoLog, str, t) {
t.Error("Info failed")
}
}
// Test that a V log goes to Info.
func TestV(t *testing.T) {
setFlags()
defer logging.swap(logging.newBuffers())
logging.verbosity.Set("2")
defer logging.verbosity.Set("0")
V(2).Info("test")
if !contains(infoLog, "I", t) {
t.Errorf("Info has wrong character: %q", contents(infoLog))
}
if !contains(infoLog, "test", t) {
t.Error("Info failed")
}
}
// Test that a vmodule enables a log in this file.
func TestVmoduleOn(t *testing.T) {
setFlags()
defer logging.swap(logging.newBuffers())
logging.vmodule.Set("glog_test=2")
defer logging.vmodule.Set("")
if !V(1) {
t.Error("V not enabled for 1")
}
if !V(2) {
t.Error("V not enabled for 2")
}
if V(3) {
t.Error("V enabled for 3")
}
V(2).Info("test")
if !contains(infoLog, "I", t) {
t.Errorf("Info has wrong character: %q", contents(infoLog))
}
if !contains(infoLog, "test", t) {
t.Error("Info failed")
}
}
// Test that a vmodule of another file does not enable a log in this file.
func TestVmoduleOff(t *testing.T) {
setFlags()
defer logging.swap(logging.newBuffers())
logging.vmodule.Set("notthisfile=2")
defer logging.vmodule.Set("")
for i := 1; i <= 3; i++ {
if V(Level(i)) {
t.Errorf("V enabled for %d", i)
}
}
V(2).Info("test")
if contents(infoLog) != "" {
t.Error("V logged incorrectly")
}
}
// vGlobs are patterns that match/don't match this file at V=2.
var vGlobs = map[string]bool{
// Easy to test the numeric match here.
"glog_test=1": false, // If -vmodule sets V to 1, V(2) will fail.
"glog_test=2": true,
"glog_test=3": true, // If -vmodule sets V to 1, V(3) will succeed.
// These all use 2 and check the patterns. All are true.
"*=2": true,
"?l*=2": true,
"????_*=2": true,
"??[mno]?_*t=2": true,
// These all use 2 and check the patterns. All are false.
"*x=2": false,
"m*=2": false,
"??_*=2": false,
"?[abc]?_*t=2": false,
}
// Test that vmodule globbing works as advertised.
func testVmoduleGlob(pat string, match bool, t *testing.T) {
setFlags()
defer logging.swap(logging.newBuffers())
defer logging.vmodule.Set("")
logging.vmodule.Set(pat)
if V(2) != Verbose(match) {
t.Errorf("incorrect match for %q: got %t expected %t", pat, V(2), match)
}
}
// Test that a vmodule globbing works as advertised.
func TestVmoduleGlob(t *testing.T) {
for glob, match := range vGlobs {
testVmoduleGlob(glob, match, t)
}
}
func TestRollover(t *testing.T) {
setFlags()
var err error
defer func(previous func(error)) { logExitFunc = previous }(logExitFunc)
logExitFunc = func(e error) {
err = e
}
defer func(previous uint64) { MaxSize = previous }(MaxSize)
MaxSize = 512
Info("x") // Be sure we have a file.
info, ok := logging.file[infoLog].(*syncBuffer)
if !ok {
t.Fatal("info wasn't created")
}
if err != nil {
t.Fatalf("info has initial error: %v", err)
}
fname0 := info.file.Name()
Info(strings.Repeat("x", int(MaxSize))) // force a rollover
if err != nil {
t.Fatalf("info has error after big write: %v", err)
}
// Make sure the next log file gets a file name with a different
// time stamp.
//
// TODO: determine whether we need to support subsecond log
// rotation. C++ does not appear to handle this case (nor does it
// handle Daylight Savings Time properly).
time.Sleep(1 * time.Second)
Info("x") // create a new file
if err != nil {
t.Fatalf("error after rotation: %v", err)
}
fname1 := info.file.Name()
if fname0 == fname1 {
t.Errorf("info.f.Name did not change: %v", fname0)
}
if info.nbytes >= MaxSize {
t.Errorf("file size was not reset: %d", info.nbytes)
}
}
func TestLogBacktraceAt(t *testing.T) {
setFlags()
defer logging.swap(logging.newBuffers())
// The peculiar style of this code simplifies line counting and maintenance of the
// tracing block below.
var infoLine string
setTraceLocation := func(file string, line int, ok bool, delta int) {
if !ok {
t.Fatal("could not get file:line")
}
_, file = filepath.Split(file)
infoLine = fmt.Sprintf("%s:%d", file, line+delta)
err := logging.traceLocation.Set(infoLine)
if err != nil {
t.Fatal("error setting log_backtrace_at: ", err)
}
}
{
// Start of tracing block. These lines know about each other's relative position.
_, file, line, ok := runtime.Caller(0)
setTraceLocation(file, line, ok, +2) // Two lines between Caller and Info calls.
Info("we want a stack trace here")
}
numAppearances := strings.Count(contents(infoLog), infoLine)
if numAppearances < 2 {
// Need 2 appearances, one in the log header and one in the trace:
// log_test.go:281: I0511 16:36:06.952398 02238 log_test.go:280] we want a stack trace here
// ...
// github.com/glog/glog_test.go:280 (0x41ba91)
// ...
// We could be more precise but that would require knowing the details
// of the traceback format, which may not be dependable.
t.Fatal("got no trace back; log is ", contents(infoLog))
}
}
func BenchmarkHeader(b *testing.B) {
for i := 0; i < b.N; i++ {
logging.putBuffer(logging.header(infoLog))
}
}
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