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author | Duco van Amstel <helcaraxan@gmail.com> | 2018-11-18 17:55:05 +0000 |
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committer | Wim <wim@42.be> | 2018-11-25 21:21:04 +0100 |
commit | 09875fe1603307080f3a4172985c5dca3bd9912d (patch) | |
tree | a23220772f6f6597d509ca71b2df3480a77b8076 /vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack.go | |
parent | f716b8fc0ff90f47b61e218ef34019b38bd70e0d (diff) | |
download | matterbridge-msglm-09875fe1603307080f3a4172985c5dca3bd9912d.tar.gz matterbridge-msglm-09875fe1603307080f3a4172985c5dca3bd9912d.tar.bz2 matterbridge-msglm-09875fe1603307080f3a4172985c5dca3bd9912d.zip |
Update direct dependencies where possible
Diffstat (limited to 'vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack.go')
-rw-r--r-- | vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack.go | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack.go b/vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack.go new file mode 100644 index 00000000..46d97c55 --- /dev/null +++ b/vendor/gopkg.in/natefinch/lumberjack.v2/lumberjack.go @@ -0,0 +1,541 @@ +// Package lumberjack provides a rolling logger. +// +// Note that this is v2.0 of lumberjack, and should be imported using gopkg.in +// thusly: +// +// import "gopkg.in/natefinch/lumberjack.v2" +// +// The package name remains simply lumberjack, and the code resides at +// https://github.com/natefinch/lumberjack under the v2.0 branch. +// +// Lumberjack is intended to be one part of a logging infrastructure. +// It is not an all-in-one solution, but instead is a pluggable +// component at the bottom of the logging stack that simply controls the files +// to which logs are written. +// +// Lumberjack plays well with any logging package that can write to an +// io.Writer, including the standard library's log package. +// +// Lumberjack assumes that only one process is writing to the output files. +// Using the same lumberjack configuration from multiple processes on the same +// machine will result in improper behavior. +package lumberjack + +import ( + "compress/gzip" + "errors" + "fmt" + "io" + "io/ioutil" + "os" + "path/filepath" + "sort" + "strings" + "sync" + "time" +) + +const ( + backupTimeFormat = "2006-01-02T15-04-05.000" + compressSuffix = ".gz" + defaultMaxSize = 100 +) + +// ensure we always implement io.WriteCloser +var _ io.WriteCloser = (*Logger)(nil) + +// Logger is an io.WriteCloser that writes to the specified filename. +// +// Logger opens or creates the logfile on first Write. If the file exists and +// is less than MaxSize megabytes, lumberjack will open and append to that file. +// If the file exists and its size is >= MaxSize megabytes, the file is renamed +// by putting the current time in a timestamp in the name immediately before the +// file's extension (or the end of the filename if there's no extension). A new +// log file is then created using original filename. +// +// Whenever a write would cause the current log file exceed MaxSize megabytes, +// the current file is closed, renamed, and a new log file created with the +// original name. Thus, the filename you give Logger is always the "current" log +// file. +// +// Backups use the log file name given to Logger, in the form +// `name-timestamp.ext` where name is the filename without the extension, +// timestamp is the time at which the log was rotated formatted with the +// time.Time format of `2006-01-02T15-04-05.000` and the extension is the +// original extension. For example, if your Logger.Filename is +// `/var/log/foo/server.log`, a backup created at 6:30pm on Nov 11 2016 would +// use the filename `/var/log/foo/server-2016-11-04T18-30-00.000.log` +// +// Cleaning Up Old Log Files +// +// Whenever a new logfile gets created, old log files may be deleted. The most +// recent files according to the encoded timestamp will be retained, up to a +// number equal to MaxBackups (or all of them if MaxBackups is 0). Any files +// with an encoded timestamp older than MaxAge days are deleted, regardless of +// MaxBackups. Note that the time encoded in the timestamp is the rotation +// time, which may differ from the last time that file was written to. +// +// If MaxBackups and MaxAge are both 0, no old log files will be deleted. +type Logger struct { + // Filename is the file to write logs to. Backup log files will be retained + // in the same directory. It uses <processname>-lumberjack.log in + // os.TempDir() if empty. + Filename string `json:"filename" yaml:"filename"` + + // MaxSize is the maximum size in megabytes of the log file before it gets + // rotated. It defaults to 100 megabytes. + MaxSize int `json:"maxsize" yaml:"maxsize"` + + // MaxAge is the maximum number of days to retain old log files based on the + // timestamp encoded in their filename. Note that a day is defined as 24 + // hours and may not exactly correspond to calendar days due to daylight + // savings, leap seconds, etc. The default is not to remove old log files + // based on age. + MaxAge int `json:"maxage" yaml:"maxage"` + + // MaxBackups is the maximum number of old log files to retain. The default + // is to retain all old log files (though MaxAge may still cause them to get + // deleted.) + MaxBackups int `json:"maxbackups" yaml:"maxbackups"` + + // LocalTime determines if the time used for formatting the timestamps in + // backup files is the computer's local time. The default is to use UTC + // time. + LocalTime bool `json:"localtime" yaml:"localtime"` + + // Compress determines if the rotated log files should be compressed + // using gzip. The default is not to perform compression. + Compress bool `json:"compress" yaml:"compress"` + + size int64 + file *os.File + mu sync.Mutex + + millCh chan bool + startMill sync.Once +} + +var ( + // currentTime exists so it can be mocked out by tests. + currentTime = time.Now + + // os_Stat exists so it can be mocked out by tests. + os_Stat = os.Stat + + // megabyte is the conversion factor between MaxSize and bytes. It is a + // variable so tests can mock it out and not need to write megabytes of data + // to disk. + megabyte = 1024 * 1024 +) + +// Write implements io.Writer. If a write would cause the log file to be larger +// than MaxSize, the file is closed, renamed to include a timestamp of the +// current time, and a new log file is created using the original log file name. +// If the length of the write is greater than MaxSize, an error is returned. +func (l *Logger) Write(p []byte) (n int, err error) { + l.mu.Lock() + defer l.mu.Unlock() + + writeLen := int64(len(p)) + if writeLen > l.max() { + return 0, fmt.Errorf( + "write length %d exceeds maximum file size %d", writeLen, l.max(), + ) + } + + if l.file == nil { + if err = l.openExistingOrNew(len(p)); err != nil { + return 0, err + } + } + + if l.size+writeLen > l.max() { + if err := l.rotate(); err != nil { + return 0, err + } + } + + n, err = l.file.Write(p) + l.size += int64(n) + + return n, err +} + +// Close implements io.Closer, and closes the current logfile. +func (l *Logger) Close() error { + l.mu.Lock() + defer l.mu.Unlock() + return l.close() +} + +// close closes the file if it is open. +func (l *Logger) close() error { + if l.file == nil { + return nil + } + err := l.file.Close() + l.file = nil + return err +} + +// Rotate causes Logger to close the existing log file and immediately create a +// new one. This is a helper function for applications that want to initiate +// rotations outside of the normal rotation rules, such as in response to +// SIGHUP. After rotating, this initiates compression and removal of old log +// files according to the configuration. +func (l *Logger) Rotate() error { + l.mu.Lock() + defer l.mu.Unlock() + return l.rotate() +} + +// rotate closes the current file, moves it aside with a timestamp in the name, +// (if it exists), opens a new file with the original filename, and then runs +// post-rotation processing and removal. +func (l *Logger) rotate() error { + if err := l.close(); err != nil { + return err + } + if err := l.openNew(); err != nil { + return err + } + l.mill() + return nil +} + +// openNew opens a new log file for writing, moving any old log file out of the +// way. This methods assumes the file has already been closed. +func (l *Logger) openNew() error { + err := os.MkdirAll(l.dir(), 0744) + if err != nil { + return fmt.Errorf("can't make directories for new logfile: %s", err) + } + + name := l.filename() + mode := os.FileMode(0644) + info, err := os_Stat(name) + if err == nil { + // Copy the mode off the old logfile. + mode = info.Mode() + // move the existing file + newname := backupName(name, l.LocalTime) + if err := os.Rename(name, newname); err != nil { + return fmt.Errorf("can't rename log file: %s", err) + } + + // this is a no-op anywhere but linux + if err := chown(name, info); err != nil { + return err + } + } + + // we use truncate here because this should only get called when we've moved + // the file ourselves. if someone else creates the file in the meantime, + // just wipe out the contents. + f, err := os.OpenFile(name, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, mode) + if err != nil { + return fmt.Errorf("can't open new logfile: %s", err) + } + l.file = f + l.size = 0 + return nil +} + +// backupName creates a new filename from the given name, inserting a timestamp +// between the filename and the extension, using the local time if requested +// (otherwise UTC). +func backupName(name string, local bool) string { + dir := filepath.Dir(name) + filename := filepath.Base(name) + ext := filepath.Ext(filename) + prefix := filename[:len(filename)-len(ext)] + t := currentTime() + if !local { + t = t.UTC() + } + + timestamp := t.Format(backupTimeFormat) + return filepath.Join(dir, fmt.Sprintf("%s-%s%s", prefix, timestamp, ext)) +} + +// openExistingOrNew opens the logfile if it exists and if the current write +// would not put it over MaxSize. If there is no such file or the write would +// put it over the MaxSize, a new file is created. +func (l *Logger) openExistingOrNew(writeLen int) error { + l.mill() + + filename := l.filename() + info, err := os_Stat(filename) + if os.IsNotExist(err) { + return l.openNew() + } + if err != nil { + return fmt.Errorf("error getting log file info: %s", err) + } + + if info.Size()+int64(writeLen) >= l.max() { + return l.rotate() + } + + file, err := os.OpenFile(filename, os.O_APPEND|os.O_WRONLY, 0644) + if err != nil { + // if we fail to open the old log file for some reason, just ignore + // it and open a new log file. + return l.openNew() + } + l.file = file + l.size = info.Size() + return nil +} + +// genFilename generates the name of the logfile from the current time. +func (l *Logger) filename() string { + if l.Filename != "" { + return l.Filename + } + name := filepath.Base(os.Args[0]) + "-lumberjack.log" + return filepath.Join(os.TempDir(), name) +} + +// millRunOnce performs compression and removal of stale log files. +// Log files are compressed if enabled via configuration and old log +// files are removed, keeping at most l.MaxBackups files, as long as +// none of them are older than MaxAge. +func (l *Logger) millRunOnce() error { + if l.MaxBackups == 0 && l.MaxAge == 0 && !l.Compress { + return nil + } + + files, err := l.oldLogFiles() + if err != nil { + return err + } + + var compress, remove []logInfo + + if l.MaxBackups > 0 && l.MaxBackups < len(files) { + preserved := make(map[string]bool) + var remaining []logInfo + for _, f := range files { + // Only count the uncompressed log file or the + // compressed log file, not both. + fn := f.Name() + if strings.HasSuffix(fn, compressSuffix) { + fn = fn[:len(fn)-len(compressSuffix)] + } + preserved[fn] = true + + if len(preserved) > l.MaxBackups { + remove = append(remove, f) + } else { + remaining = append(remaining, f) + } + } + files = remaining + } + if l.MaxAge > 0 { + diff := time.Duration(int64(24*time.Hour) * int64(l.MaxAge)) + cutoff := currentTime().Add(-1 * diff) + + var remaining []logInfo + for _, f := range files { + if f.timestamp.Before(cutoff) { + remove = append(remove, f) + } else { + remaining = append(remaining, f) + } + } + files = remaining + } + + if l.Compress { + for _, f := range files { + if !strings.HasSuffix(f.Name(), compressSuffix) { + compress = append(compress, f) + } + } + } + + for _, f := range remove { + errRemove := os.Remove(filepath.Join(l.dir(), f.Name())) + if err == nil && errRemove != nil { + err = errRemove + } + } + for _, f := range compress { + fn := filepath.Join(l.dir(), f.Name()) + errCompress := compressLogFile(fn, fn+compressSuffix) + if err == nil && errCompress != nil { + err = errCompress + } + } + + return err +} + +// millRun runs in a goroutine to manage post-rotation compression and removal +// of old log files. +func (l *Logger) millRun() { + for _ = range l.millCh { + // what am I going to do, log this? + _ = l.millRunOnce() + } +} + +// mill performs post-rotation compression and removal of stale log files, +// starting the mill goroutine if necessary. +func (l *Logger) mill() { + l.startMill.Do(func() { + l.millCh = make(chan bool, 1) + go l.millRun() + }) + select { + case l.millCh <- true: + default: + } +} + +// oldLogFiles returns the list of backup log files stored in the same +// directory as the current log file, sorted by ModTime +func (l *Logger) oldLogFiles() ([]logInfo, error) { + files, err := ioutil.ReadDir(l.dir()) + if err != nil { + return nil, fmt.Errorf("can't read log file directory: %s", err) + } + logFiles := []logInfo{} + + prefix, ext := l.prefixAndExt() + + for _, f := range files { + if f.IsDir() { + continue + } + if t, err := l.timeFromName(f.Name(), prefix, ext); err == nil { + logFiles = append(logFiles, logInfo{t, f}) + continue + } + if t, err := l.timeFromName(f.Name(), prefix, ext+compressSuffix); err == nil { + logFiles = append(logFiles, logInfo{t, f}) + continue + } + // error parsing means that the suffix at the end was not generated + // by lumberjack, and therefore it's not a backup file. + } + + sort.Sort(byFormatTime(logFiles)) + + return logFiles, nil +} + +// timeFromName extracts the formatted time from the filename by stripping off +// the filename's prefix and extension. This prevents someone's filename from +// confusing time.parse. +func (l *Logger) timeFromName(filename, prefix, ext string) (time.Time, error) { + if !strings.HasPrefix(filename, prefix) { + return time.Time{}, errors.New("mismatched prefix") + } + if !strings.HasSuffix(filename, ext) { + return time.Time{}, errors.New("mismatched extension") + } + ts := filename[len(prefix) : len(filename)-len(ext)] + return time.Parse(backupTimeFormat, ts) +} + +// max returns the maximum size in bytes of log files before rolling. +func (l *Logger) max() int64 { + if l.MaxSize == 0 { + return int64(defaultMaxSize * megabyte) + } + return int64(l.MaxSize) * int64(megabyte) +} + +// dir returns the directory for the current filename. +func (l *Logger) dir() string { + return filepath.Dir(l.filename()) +} + +// prefixAndExt returns the filename part and extension part from the Logger's +// filename. +func (l *Logger) prefixAndExt() (prefix, ext string) { + filename := filepath.Base(l.filename()) + ext = filepath.Ext(filename) + prefix = filename[:len(filename)-len(ext)] + "-" + return prefix, ext +} + +// compressLogFile compresses the given log file, removing the +// uncompressed log file if successful. +func compressLogFile(src, dst string) (err error) { + f, err := os.Open(src) + if err != nil { + return fmt.Errorf("failed to open log file: %v", err) + } + defer f.Close() + + fi, err := os_Stat(src) + if err != nil { + return fmt.Errorf("failed to stat log file: %v", err) + } + + if err := chown(dst, fi); err != nil { + return fmt.Errorf("failed to chown compressed log file: %v", err) + } + + // If this file already exists, we presume it was created by + // a previous attempt to compress the log file. + gzf, err := os.OpenFile(dst, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, fi.Mode()) + if err != nil { + return fmt.Errorf("failed to open compressed log file: %v", err) + } + defer gzf.Close() + + gz := gzip.NewWriter(gzf) + + defer func() { + if err != nil { + os.Remove(dst) + err = fmt.Errorf("failed to compress log file: %v", err) + } + }() + + if _, err := io.Copy(gz, f); err != nil { + return err + } + if err := gz.Close(); err != nil { + return err + } + if err := gzf.Close(); err != nil { + return err + } + + if err := f.Close(); err != nil { + return err + } + if err := os.Remove(src); err != nil { + return err + } + + return nil +} + +// logInfo is a convenience struct to return the filename and its embedded +// timestamp. +type logInfo struct { + timestamp time.Time + os.FileInfo +} + +// byFormatTime sorts by newest time formatted in the name. +type byFormatTime []logInfo + +func (b byFormatTime) Less(i, j int) bool { + return b[i].timestamp.After(b[j].timestamp) +} + +func (b byFormatTime) Swap(i, j int) { + b[i], b[j] = b[j], b[i] +} + +func (b byFormatTime) Len() int { + return len(b) +} |