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