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