text: # 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()
  