twisted/conch/mixin.py

   1 # -*- test-case-name: twisted.conch.test.test_mixin -*-
   2 # Copyright (c) Twisted Matrix Laboratories.
   3 # See LICENSE for details.
   4
   5 """
   6 Experimental optimization
   7
   8 This module provides a single mixin class which allows protocols to
   9 collapse numerous small writes into a single larger one.
  10
  11 @author: Jp Calderone
  12 """
  13
  14 from twisted.internet import reactor
  15
  16 class BufferingMixin:
  17     """Mixin which adds write buffering.
  18     """
  19     _delayedWriteCall = None
  20     bytes = None
  21
  22     DELAY = 0.0
  23
  24     def schedule(self):
  25         return reactor.callLater(self.DELAY, self.flush)
  26
  27     def reschedule(self, token):
  28         token.reset(self.DELAY)
  29
  30     def write(self, bytes):
  31         """Buffer some bytes to be written soon.
  32
  33         Every call to this function delays the real write by C{self.DELAY}
  34         seconds.  When the delay expires, all collected bytes are written
  35         to the underlying transport using L{ITransport.writeSequence}.
  36         """
  37         if self._delayedWriteCall is None:
  38             self.bytes = []
  39             self._delayedWriteCall = self.schedule()
  40         else:
  41             self.reschedule(self._delayedWriteCall)
  42         self.bytes.append(bytes)
  43
  44     def flush(self):
  45         """Flush the buffer immediately.
  46         """
  47         self._delayedWriteCall = None
  48         self.transport.writeSequence(self.bytes)
  49         self.bytes = None