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

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