func()

in plugins/inputs/logfile/tail/watch/inotify.go [66:137]

• 59 lines of code
• 16 McCabe index (conditional complexity)

func (fw *InotifyFileWatcher) ChangeEvents(t *tomb.Tomb, pos int64) (*FileChanges, error) {
	err := Watch(fw.Filename)
	if err != nil {
		return nil, err
	}

	changes := NewFileChanges()
	fw.Size = pos

	go func() {

		events := Events(fw.Filename)

		for {
			prevSize := fw.Size

			var evt fsnotify.Event
			var ok bool

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

			switch {
			//With an open fd, unlink(fd) - inotify returns IN_ATTRIB (==fsnotify.Chmod)
			case evt.Op&fsnotify.Chmod == fsnotify.Chmod:
				if _, err := os.Stat(fw.Filename); err != nil {
					if !os.IsNotExist(err) {
						return
					}
				}
				fallthrough

			case evt.Op&fsnotify.Remove == fsnotify.Remove:
				fallthrough

			case evt.Op&fsnotify.Rename == fsnotify.Rename:
				RemoveWatch(fw.Filename)
				changes.NotifyDeleted()
				return

			case evt.Op&fsnotify.Write == fsnotify.Write:
				fi, err := os.Stat(fw.Filename)
				if err != nil {
					if os.IsNotExist(err) {
						RemoveWatch(fw.Filename)
						changes.NotifyDeleted()
						return
					}
					log.Printf("E! [logfile] 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, nil
}