git.maemo.org Git - maevies/blob - ui/maeviesui/util/asyncworker.py

   1 # -*- coding: utf-8 -*-
   2
   3 ###########################################################################
   4 #    SeriesFinale
   5 #    Copyright (C) 2009 Joaquim Rocha <jrocha@igalia.com>
   6 #
   7 #    This program is free software: you can redistribute it and/or modify
   8 #    it under the terms of the GNU General Public License as published by
   9 #    the Free Software Foundation, either version 3 of the License, or
  10 #    (at your option) any later version.
  11 #
  12 #    This program is distributed in the hope that it will be useful,
  13 #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 #    GNU General Public License for more details.
  16 #
  17 #    You should have received a copy of the GNU General Public License
  18 #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 ###########################################################################
  20
  21 from threading import Thread
  22 import Queue
  23 import gobject
  24 import logging
  25 logging.basicConfig(level=logging.DEBUG)
  26
  27 class AsyncItem(object):
  28
  29     def __init__(self, target_method, target_method_args, finish_callback=None, finish_callback_args=()):
  30         self.target_method = target_method
  31         self.target_method_args = target_method_args
  32         self.finish_callback = finish_callback
  33         self.finish_callback_args = finish_callback_args
  34         self.canceled = False
  35
  36     def run(self):
  37         if self.canceled:
  38             return
  39         results = error = None
  40         try:
  41             results = self.target_method(*self.target_method_args)
  42         except Exception, exception:
  43             logging.debug(str(exception))
  44             error = exception
  45         if self.canceled or not self.finish_callback:
  46             return
  47         self.finish_callback_args += (results,)
  48         self.finish_callback_args += (error,)
  49         gobject.idle_add(self.finish_callback, *self.finish_callback_args)
  50
  51     def cancel(self):
  52         self.canceled = True
  53
  54 class AsyncWorker(Thread):
  55
  56     def __init__(self):
  57         Thread.__init__(self)
  58         self.queue = Queue.Queue(0)
  59         self.stopped = False
  60         self.async_item = None
  61         self.item_number = -1
  62
  63     def run(self):
  64         while not self.stopped:
  65             if self.queue.empty():
  66                 self.stop()
  67                 break
  68             try:
  69                 self.async_item = self.queue.get()
  70                 self.item_number += 1
  71                 self.async_item.run()
  72                 self.queue.task_done()
  73                 self.async_item = None
  74             except Exception, exception:
  75                 logging.debug(str(exception))
  76                 self.stop()
  77
  78     def stop(self):
  79         self.stopped = True
  80         if self.async_item:
  81             self.async_item.cancel()
  82