git.maemo.org Git - gonvert/blob - src/util/qore_utils.py

   1 import logging
   2
   3 from PyQt4 import QtCore
   4
   5 import misc
   6
   7
   8 _moduleLogger = logging.getLogger(__name__)
   9
  10
  11 class QThread44(QtCore.QThread):
  12         """
  13         This is to imitate QThread in Qt 4.4+ for when running on older version
  14         See http://labs.trolltech.com/blogs/2010/06/17/youre-doing-it-wrong
  15         (On Lucid I have Qt 4.7 and this is still an issue)
  16         """
  17
  18         def __init__(self, parent = None):
  19                 QtCore.QThread.__init__(self, parent)
  20
  21         def run(self):
  22                 self.exec_()
  23
  24
  25 class _ParentThread(QtCore.QObject):
  26
  27         def __init__(self, pool):
  28                 QtCore.QObject.__init__(self)
  29                 self._pool = pool
  30
  31         @QtCore.pyqtSlot(object)
  32         @misc.log_exception(_moduleLogger)
  33         def _on_task_complete(self, taskResult):
  34                 on_success, on_error, isError, result = taskResult
  35                 if not self._pool._isRunning:
  36                         if isError:
  37                                 _moduleLogger.error("Masking: %s" % (result, ))
  38                         isError = True
  39                         result = StopIteration("Cancelling all callbacks")
  40                 callback = on_success if not isError else on_error
  41                 try:
  42                         callback(result)
  43                 except Exception:
  44                         _moduleLogger.exception("Callback errored")
  45
  46
  47 class _WorkerThread(QtCore.QObject):
  48
  49         taskComplete  = QtCore.pyqtSignal(object)
  50
  51         def __init__(self, pool):
  52                 QtCore.QObject.__init__(self)
  53                 self._pool = pool
  54
  55         @QtCore.pyqtSlot(object)
  56         @misc.log_exception(_moduleLogger)
  57         def _on_task_added(self, task):
  58                 if not self._pool._isRunning:
  59                         _moduleLogger.error("Dropping task")
  60
  61                 func, args, kwds, on_success, on_error = task
  62
  63                 try:
  64                         result = func(*args, **kwds)
  65                         isError = False
  66                 except Exception, e:
  67                         _moduleLogger.error("Error, passing it back to the main thread")
  68                         result = e
  69                         isError = True
  70
  71                 taskResult = on_success, on_error, isError, result
  72                 self.taskComplete.emit(taskResult)
  73
  74         @QtCore.pyqtSlot()
  75         @misc.log_exception(_moduleLogger)
  76         def _on_stop_requested(self):
  77                 self._pool._thread.quit()
  78
  79
  80 class AsyncPool(QtCore.QObject):
  81
  82         _addTask = QtCore.pyqtSignal(object)
  83         _stopPool = QtCore.pyqtSignal()
  84
  85         def __init__(self):
  86                 QtCore.QObject.__init__(self)
  87                 self._thread = QThread44()
  88                 self._isRunning = True
  89                 self._parent = _ParentThread(self)
  90                 self._worker = _WorkerThread(self)
  91                 self._worker.moveToThread(self._thread)
  92
  93                 self._addTask.connect(self._worker._on_task_added)
  94                 self._worker.taskComplete.connect(self._parent._on_task_complete)
  95                 self._stopPool.connect(self._worker._on_stop_requested)
  96
  97         def start(self):
  98                 self._thread.start()
  99
 100         def stop(self):
 101                 self._isRunning = False
 102                 self._stopPool.emit()
 103
 104         def add_task(self, func, args, kwds, on_success, on_error):
 105                 assert self._isRunning, "Task queue not started"
 106                 task = func, args, kwds, on_success, on_error
 107                 self._addTask.emit(task)