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Viewing changes to src/twisted/protocols/stateful.py

  • Committer: Thomas Hervé
  • Date: 2009-07-08 13:52:04 UTC
  • Revision ID: thomas@canonical.com-20090708135204-df5eesrthifpylf8
Remove twisted copy

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src/twisted/protocols/stateful.py
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# -*- test-case-name: twisted.test.test_stateful -*-
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# Copyright (c) 2001-2004 Twisted Matrix Laboratories.
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# See LICENSE for details.
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from twisted.internet import protocol
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try:
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    from cStringIO import StringIO
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except ImportError:
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    from StringIO import StringIO
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class StatefulProtocol(protocol.Protocol):
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    """A Protocol that stores state for you.
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    state is a pair (function, num_bytes). When num_bytes bytes of data arrives
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    from the network, function is called. It is expected to return the next
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    state or None to keep same state. Initial state is returned by
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    getInitialState (override it).
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    """
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    _sful_data = None, None, 0
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    def makeConnection(self, transport):
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        protocol.Protocol.makeConnection(self, transport)
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        self._sful_data = self.getInitialState(), StringIO(), 0
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    def getInitialState(self):
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        raise NotImplementedError
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    def dataReceived(self, data):
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        state, buffer, offset = self._sful_data
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        buffer.seek(0, 2)
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        buffer.write(data)
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        blen = buffer.tell() # how many bytes total is in the buffer
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        buffer.seek(offset)
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        while blen - offset >= state[1]:
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            d = buffer.read(state[1])
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            offset += state[1]
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            next = state[0](d)
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            if self.transport.disconnecting: # XXX: argh stupid hack borrowed right from LineReceiver
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                return # dataReceived won't be called again, so who cares about consistent state
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            if next:
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                state = next
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        if offset != 0:
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            b = buffer.read()
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            buffer.reset()
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            buffer.truncate()
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            buffer.write(b)
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            offset = 0
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        self._sful_data = state, buffer, offset
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