.local/lib/python2.7/site-packages/trollius/executor.py

   1 from .log import logger
   2
   3 __all__ = (
   4     'CancelledError', 'TimeoutError',
   5     'FIRST_COMPLETED', 'FIRST_EXCEPTION', 'ALL_COMPLETED',
   6     )
   7
   8 # Argument for default thread pool executor creation.
   9 _MAX_WORKERS = 5
  10
  11 try:
  12     import concurrent.futures
  13     import concurrent.futures._base
  14 except ImportError:
  15     FIRST_COMPLETED = 'FIRST_COMPLETED'
  16     FIRST_EXCEPTION = 'FIRST_EXCEPTION'
  17     ALL_COMPLETED = 'ALL_COMPLETED'
  18
  19     class Future(object):
  20         def __init__(self, callback, args):
  21             try:
  22                 self._result = callback(*args)
  23                 self._exception = None
  24             except Exception as err:
  25                 self._result = None
  26                 self._exception = err
  27             self.callbacks = []
  28
  29         def cancelled(self):
  30             return False
  31
  32         def done(self):
  33             return True
  34
  35         def exception(self):
  36             return self._exception
  37
  38         def result(self):
  39             if self._exception is not None:
  40                 raise self._exception
  41             else:
  42                 return self._result
  43
  44         def add_done_callback(self, callback):
  45             callback(self)
  46
  47     class Error(Exception):
  48         """Base class for all future-related exceptions."""
  49         pass
  50
  51     class CancelledError(Error):
  52         """The Future was cancelled."""
  53         pass
  54
  55     class TimeoutError(Error):
  56         """The operation exceeded the given deadline."""
  57         pass
  58
  59     class SynchronousExecutor:
  60         """
  61         Synchronous executor: submit() blocks until it gets the result.
  62         """
  63         def submit(self, callback, *args):
  64             return Future(callback, args)
  65
  66         def shutdown(self, wait):
  67             pass
  68
  69     def get_default_executor():
  70         logger.error("concurrent.futures module is missing: "
  71                      "use a synchrounous executor as fallback!")
  72         return SynchronousExecutor()
  73 else:
  74     FIRST_COMPLETED = concurrent.futures.FIRST_COMPLETED
  75     FIRST_EXCEPTION = concurrent.futures.FIRST_EXCEPTION
  76     ALL_COMPLETED = concurrent.futures.ALL_COMPLETED
  77
  78     Future = concurrent.futures.Future
  79     Error = concurrent.futures._base.Error
  80     CancelledError = concurrent.futures.CancelledError
  81     TimeoutError = concurrent.futures.TimeoutError
  82
  83     def get_default_executor():
  84         return concurrent.futures.ThreadPoolExecutor(_MAX_WORKERS)