diff options
Diffstat (limited to 'QMP')
| -rw-r--r-- | QMP/qmp.py | 157 |
1 files changed, 106 insertions, 51 deletions
@@ -1,6 +1,6 @@ # QEMU Monitor Protocol Python class # -# Copyright (C) 2009 Red Hat Inc. +# Copyright (C) 2009, 2010 Red Hat Inc. # # Authors: # Luiz Capitulino <lcapitulino@redhat.com> @@ -8,7 +8,9 @@ # 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 +import json +import errno +import socket class QMPError(Exception): pass @@ -16,61 +18,114 @@ class QMPError(Exception): class QMPConnectError(QMPError): pass +class QMPCapabilitiesError(QMPError): + pass + class QEMUMonitorProtocol: + def __init__(self, address): + """ + Create a QEMUMonitorProtocol class. + + @param address: QEMU address, can be either a unix socket path (string) + or a tuple in the form ( address, port ) for a TCP + connection + @note No connection is established, this is done by the connect() method + """ + self.__events = [] + self.__address = address + self.__sock = self.__get_sock() + self.__sockfile = self.__sock.makefile() + + def __get_sock(self): + if isinstance(self.__address, tuple): + family = socket.AF_INET + else: + family = socket.AF_UNIX + return socket.socket(family, socket.SOCK_STREAM) + + def __json_read(self): + while True: + data = self.__sockfile.readline() + if not data: + return + resp = json.loads(data) + if 'event' in resp: + self.__events.append(resp) + continue + return resp + + error = socket.error + def connect(self): - self.sock.connect(self.filename) - data = self.__json_read() - if data == None: - raise QMPConnectError - if not data.has_key('QMP'): + """ + Connect to the QMP Monitor and perform capabilities negotiation. + + @return QMP greeting dict + @raise socket.error on socket connection errors + @raise QMPConnectError if the greeting is not received + @raise QMPCapabilitiesError if fails to negotiate capabilities + """ + self.__sock.connect(self.__address) + greeting = self.__json_read() + if greeting is None or not greeting.has_key('QMP'): raise QMPConnectError - return data['QMP']['capabilities'] + # Greeting seems ok, negotiate capabilities + resp = self.cmd('qmp_capabilities') + if "return" in resp: + return greeting + raise QMPCapabilitiesError - def close(self): - self.sock.close() + def cmd_obj(self, qmp_cmd): + """ + Send a QMP command to the QMP Monitor. - def send_raw(self, line): - self.sock.send(str(line)) + @param qmp_cmd: QMP command to be sent as a Python dict + @return QMP response as a Python dict or None if the connection has + been closed + """ + try: + self.__sock.sendall(json.dumps(qmp_cmd)) + except socket.error, err: + if err[0] == errno.EPIPE: + return + raise socket.error(err) 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 cmd(self, name, args=None, id=None): + """ + Build a QMP command and send it to the QMP Monitor. - def __json_read(self): + @param name: command name (string) + @param args: command arguments (dict) + @param id: command id (dict, list, string or int) + """ + qmp_cmd = { 'execute': name } + if args: + qmp_cmd['arguments'] = args + if id: + qmp_cmd['id'] = id + return self.cmd_obj(qmp_cmd) + + def get_events(self): + """ + Get a list of available QMP events. + """ + self.__sock.setblocking(0) 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() + self.__json_read() + except socket.error, err: + if err[0] == errno.EAGAIN: + # No data available + pass + self.__sock.setblocking(1) + return self.__events + + def clear_events(self): + """ + Clear current list of pending events. + """ + self.__events = [] + + def close(self): + self.__sock.close() + self.__sockfile.close() |
