marshall.py

#! /usr/bin/env python

# =============================================================================
# This file is part of profile-qt
#
# Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
# All rights reserved.
#
# Contact: Sakari Poussa <sakari.poussa@nokia.com>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# Redistributions of source code must retain the above copyright notice, 
# this list of conditions and the following disclaimer. Redistributions in 
# binary form must reproduce the above copyright notice, this list of 
# conditions and the following disclaimer in the documentation  and/or 
# other materials provided with the distribution.
#
# Neither the name of Nokia Corporation nor the names of its contributors
# may be used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 
# OF THE POSSIBILITY OF SUCH DAMAGE.
# =============================================================================


import sys,pickle,struct,cStringIO

def debugf(m):
    #sys.stderr.write(m)
    pass

def message_send(socket, tag, *dta):
    msg = (tag,dta)
    body = cStringIO.StringIO()
    pickle.dump(msg, body)
    body = body.getvalue()

    head = struct.pack(">I", len(body))
    data = head + body

    debugf("TX: %s\n" % repr(msg))

    socket.sendall(data)

def message_recv(socket):
    fmt = ">I"
    cnt = struct.calcsize(fmt)
    msg = socket.recv(cnt)
    if len(msg) != cnt:
        debugf("RX: %s\n" % "no head")
        return None

    cnt = struct.unpack(fmt, msg)[0]
    msg = socket.recv(cnt)
    if len(msg) != cnt:
        debugf("RX: %s\n" % "no body")
        return None

    msg = cStringIO.StringIO(msg)
    msg = pickle.load(msg)
    debugf("RX: %s\n" % repr(msg))
    return msg