# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Loopback helper used in test_ssh and test_recvline
"""

from __future__ import division, absolute_import

from twisted.protocols import loopback
class LoopbackRelay(loopback.LoopbackRelay):
    clearCall = None

    def logPrefix(self):
        return "LoopbackRelay(%r)" % (self.target.__class__.__name__,)


    def write(self, data):
        loopback.LoopbackRelay.write(self, data)
        if self.clearCall is not None:
            self.clearCall.cancel()

        from twisted.internet import reactor
        self.clearCall = reactor.callLater(0, self._clearBuffer)


    def _clearBuffer(self):
        self.clearCall = None
        loopback.LoopbackRelay.clearBuffer(self)