src/dirtrigger.py

   1 import logging
   2 import threading
   3 import time
   4 from watchdog.events import DirDeletedEvent, FileDeletedEvent, FileSystemEventHandler
   5 from watchdog.observers import Observer
   6
   7 class DirTrigger(FileSystemEventHandler):
   8
   9     def __init__(self, dir_path, cool_time, max_time):
  10         self._got_event = False
  11         self._last_event_time = 0.0
  12         self._last_reset_time = 0.0
  13         self._cool_time = cool_time
  14         self._max_time = max_time
  15         self._lock = threading.Lock()
  16         self._observer = Observer()
  17         self._observer.schedule(self, path=dir_path, recursive=True)
  18
  19     def start(self):
  20         try:
  21             self._observer.start()
  22         except Exception as e:
  23             logging.warning("Error starting file observer for %s: %s", dir_path, str(e))
  24
  25     def stop(self):
  26         self._observer.stop()
  27
  28     def is_triggering(self):
  29         self._lock.acquire()
  30         try:
  31             now = time.time()
  32             return ( self._got_event and
  33                      (now - self._last_event_time > self._cool_time) ) or \
  34                      now - self._last_reset_time > self._max_time
  35         finally:
  36             self._lock.release()
  37
  38     def reset(self):
  39         self._lock.acquire()
  40         try:
  41             self._got_event = False
  42             self._last_reset_time = time.time()
  43         finally:
  44             self._lock.release()
  45
  46     def on_any_event(self, event):
  47         if event.event_type == FileDeletedEvent or event.event_type == DirDeletedEvent:
  48             return
  49
  50         self._lock.acquire()
  51         try:
  52             self._got_event = True
  53             self._last_event_time = time.time()
  54         finally:
  55             self._lock.release()