Ejemplo n.º 1
0
func (fw *PollingFileWatcher) ChangeEvents(t *tomb.Tomb, origFi os.FileInfo) *FileChanges {
	changes := NewFileChanges()
	var prevModTime time.Time

	// XXX: use tomb.Tomb to cleanly manage these goroutines. replace
	// the fatal (below) with tomb's Kill.

	fw.Size = origFi.Size()

	go func() {
		defer changes.Close()

		var retry int = 0

		prevSize := fw.Size
		for {
			select {
			case <-t.Dying():
				return
			default:
			}

			time.Sleep(POLL_DURATION)
			fi, err := os.Stat(fw.Filename)
			if err != nil {
				if os.IsNotExist(err) {
					// File does not exist (has been deleted).
					changes.NotifyDeleted()
					return
				}

				if permissionErrorRetry(err, &retry) {
					continue
				}

				// XXX: report this error back to the user
				util.Fatal("Failed to stat file %v: %v", fw.Filename, err)
			}

			// File got moved/renamed?
			if !os.SameFile(origFi, fi) {
				changes.NotifyDeleted()
				return
			}

			// File got truncated?
			fw.Size = fi.Size()
			if prevSize > 0 && prevSize > fw.Size {
				changes.NotifyTruncated()
				prevSize = fw.Size
				continue
			}
			prevSize = fw.Size

			// File was appended to (changed)?
			modTime := fi.ModTime()
			if modTime != prevModTime {
				prevModTime = modTime
				changes.NotifyModified()
			}
		}
	}()

	return changes
}
Ejemplo n.º 2
0
func (fw *InotifyFileWatcher) ChangeEvents(t *tomb.Tomb, fi os.FileInfo) *FileChanges {
	changes := NewFileChanges()

	err := fw.w.Watch(fw.Filename)
	if err != nil {
		util.Fatal("Error watching %v: %v", fw.Filename, err)
	}

	fw.Size = fi.Size()

	go func() {
		defer fw.w.RemoveWatch(fw.Filename)
		defer changes.Close()

		for {
			prevSize := fw.Size

			var evt *fsnotify.FileEvent
			var ok bool

			select {
			case evt, ok = <-fw.w.Event:
				if !ok {
					return
				}
			case <-t.Dying():
				return
			}

			switch {
			case evt.IsDelete():
				fallthrough

			case evt.IsRename():
				changes.NotifyDeleted()
				return

			case evt.IsModify():
				fi, err := os.Stat(fw.Filename)
				if err != nil {
					if os.IsNotExist(err) {
						changes.NotifyDeleted()
						return
					}
					// XXX: report this error back to the user
					util.Fatal("Failed to stat file %v: %v", fw.Filename, err)
				}
				fw.Size = fi.Size()

				if prevSize > 0 && prevSize > fw.Size {
					changes.NotifyTruncated()
				} else {
					changes.NotifyModified()
				}
				prevSize = fw.Size
			}
		}
	}()

	return changes
}