Archipelago » qemu

# QEMU Monitor Protocol Python class

# 

# Copyright (C) 2009 Red Hat Inc.

#

# Authors:

#  Luiz Capitulino <lcapitulino@redhat.com>

#

# This work is licensed under the terms of the GNU GPL, version 2.  See

# the COPYING file in the top-level directory.

import socket, json

class QMPError(Exception):

    pass

class QMPConnectError(QMPError):

    pass

class QEMUMonitorProtocol:

    def connect(self):

        self.sock.connect(self.filename)

        data = self.__json_read()

        if data == None:

            raise QMPConnectError

        if not data.has_key('QMP'):

            raise QMPConnectError

        return data['QMP']['capabilities']

    def close(self):

        self.sock.close()

    def send_raw(self, line):

        self.sock.send(str(line))

        return self.__json_read()

    def send(self, cmdline):

        cmd = self.__build_cmd(cmdline)

        self.__json_send(cmd)

        resp = self.__json_read()

        if resp == None:

            return

        elif resp.has_key('error'):

            return resp['error']

        else:

            return resp['return']

    def __build_cmd(self, cmdline):

        cmdargs = cmdline.split()

        qmpcmd = { 'execute': cmdargs[0], 'arguments': {} }

        for arg in cmdargs[1:]:

            opt = arg.split('=')

            try:

                value = int(opt[1])

            except ValueError:

                value = opt[1]

            qmpcmd['arguments'][opt[0]] = value

        return qmpcmd

    def __json_send(self, cmd):

        # XXX: We have to send any additional char, otherwise

        # the Server won't read our input

        self.sock.send(json.dumps(cmd) + ' ')

    def __json_read(self):

        try:

            while True:

                line = json.loads(self.sockfile.readline())

                if not 'event' in line:

                    return line

        except ValueError:

            return

    def __init__(self, filename):

        self.filename = filename

        self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)

        self.sockfile = self.sock.makefile()