PPC: rename msync to msync_4xx
[qemu.git] / QMP / qmp.py
1 # QEMU Monitor Protocol Python class
2 #
3 # Copyright (C) 2009, 2010 Red Hat Inc.
4 #
5 # Authors:
6 # Luiz Capitulino <lcapitulino@redhat.com>
7 #
8 # This work is licensed under the terms of the GNU GPL, version 2. See
9 # the COPYING file in the top-level directory.
10
11 import json
12 import errno
13 import socket
14
15 class QMPError(Exception):
16 pass
17
18 class QMPConnectError(QMPError):
19 pass
20
21 class QMPCapabilitiesError(QMPError):
22 pass
23
24 class QEMUMonitorProtocol:
25 def __init__(self, address, server=False):
26 """
27 Create a QEMUMonitorProtocol class.
28
29 @param address: QEMU address, can be either a unix socket path (string)
30 or a tuple in the form ( address, port ) for a TCP
31 connection
32 @param server: server mode listens on the socket (bool)
33 @raise socket.error on socket connection errors
34 @note No connection is established, this is done by the connect() or
35 accept() methods
36 """
37 self.__events = []
38 self.__address = address
39 self.__sock = self.__get_sock()
40 if server:
41 self.__sock.bind(self.__address)
42 self.__sock.listen(1)
43
44 def __get_sock(self):
45 if isinstance(self.__address, tuple):
46 family = socket.AF_INET
47 else:
48 family = socket.AF_UNIX
49 return socket.socket(family, socket.SOCK_STREAM)
50
51 def __negotiate_capabilities(self):
52 self.__sockfile = self.__sock.makefile()
53 greeting = self.__json_read()
54 if greeting is None or not greeting.has_key('QMP'):
55 raise QMPConnectError
56 # Greeting seems ok, negotiate capabilities
57 resp = self.cmd('qmp_capabilities')
58 if "return" in resp:
59 return greeting
60 raise QMPCapabilitiesError
61
62 def __json_read(self, only_event=False):
63 while True:
64 data = self.__sockfile.readline()
65 if not data:
66 return
67 resp = json.loads(data)
68 if 'event' in resp:
69 self.__events.append(resp)
70 if not only_event:
71 continue
72 return resp
73
74 error = socket.error
75
76 def connect(self):
77 """
78 Connect to the QMP Monitor and perform capabilities negotiation.
79
80 @return QMP greeting dict
81 @raise socket.error on socket connection errors
82 @raise QMPConnectError if the greeting is not received
83 @raise QMPCapabilitiesError if fails to negotiate capabilities
84 """
85 self.__sock.connect(self.__address)
86 return self.__negotiate_capabilities()
87
88 def accept(self):
89 """
90 Await connection from QMP Monitor and perform capabilities negotiation.
91
92 @return QMP greeting dict
93 @raise socket.error on socket connection errors
94 @raise QMPConnectError if the greeting is not received
95 @raise QMPCapabilitiesError if fails to negotiate capabilities
96 """
97 self.__sock, _ = self.__sock.accept()
98 return self.__negotiate_capabilities()
99
100 def cmd_obj(self, qmp_cmd):
101 """
102 Send a QMP command to the QMP Monitor.
103
104 @param qmp_cmd: QMP command to be sent as a Python dict
105 @return QMP response as a Python dict or None if the connection has
106 been closed
107 """
108 try:
109 self.__sock.sendall(json.dumps(qmp_cmd))
110 except socket.error, err:
111 if err[0] == errno.EPIPE:
112 return
113 raise socket.error(err)
114 return self.__json_read()
115
116 def cmd(self, name, args=None, id=None):
117 """
118 Build a QMP command and send it to the QMP Monitor.
119
120 @param name: command name (string)
121 @param args: command arguments (dict)
122 @param id: command id (dict, list, string or int)
123 """
124 qmp_cmd = { 'execute': name }
125 if args:
126 qmp_cmd['arguments'] = args
127 if id:
128 qmp_cmd['id'] = id
129 return self.cmd_obj(qmp_cmd)
130
131 def get_events(self, wait=False):
132 """
133 Get a list of available QMP events.
134
135 @param wait: block until an event is available (bool)
136 """
137 self.__sock.setblocking(0)
138 try:
139 self.__json_read()
140 except socket.error, err:
141 if err[0] == errno.EAGAIN:
142 # No data available
143 pass
144 self.__sock.setblocking(1)
145 if not self.__events and wait:
146 self.__json_read(only_event=True)
147 return self.__events
148
149 def clear_events(self):
150 """
151 Clear current list of pending events.
152 """
153 self.__events = []
154
155 def close(self):
156 self.__sock.close()
157 self.__sockfile.close()