forked from samuel/python-gearman
/
connection.py
212 lines (169 loc) · 6.12 KB
/
connection.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
import socket, struct, select, errno, logging
from time import time
from gearman.protocol import DEFAULT_PORT, pack_command, parse_command
log = logging.getLogger("gearman")
class GearmanConnection(object):
class ConnectionError(Exception):
pass
def __init__(self, host, port=DEFAULT_PORT, sock=None, timeout=None, reconnect_timeout=60*2):
"""
A connection to a Gearman server.
"""
if not sock:
self.sock = None
self.connected = False
else:
self.sock = sock
self.connected = True
if ':' in host:
host, port = (host.split(':') + [0])[:2]
port = int(port) or DEFAULT_PORT
self.addr = (host, port)
else:
port = port or DEFAULT_PORT
self.addr = (host, port)
self.hostspec = "%s:%d" % (host, port)
self.timeout = timeout
self.reconnect_timeout = reconnect_timeout
self.is_dead = False
self._reset_queues()
def _reset_queues(self):
self.in_buffer = ""
self.out_buffer = ""
self.waiting_for_handles = []
def fileno(self):
return self.sock.fileno()
def writable(self):
return self.connected and len(self.out_buffer) != 0
def readable(self):
return self.connected
def connect(self):
"""Connect to the server. Raise ConnectionError if connection fails."""
if self.connected:
return
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.settimeout(self.timeout)
try:
self.sock.connect(self.addr)
except (socket.error, socket.timeout), exc:
self.sock = None
self.is_dead = True
raise self.ConnectionError(str(exc))
self._reset_queues()
self.is_dead = False
self.connected = True
self.sock.setblocking(0)
self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, struct.pack("L", 1))
def is_dead():
def fget(self):
if self._is_dead and time() >= self._retry_at:
self._is_dead = False
# try:
# self.connect()
# except self.ConnectionError:
# pass
return self._is_dead
def fset(self, value):
self._is_dead = value
self._retry_at = value and time() + self.reconnect_timeout or None
return locals()
is_dead = property(**is_dead())
def recv(self, size=4096):
"""
Returns a list of commands: [(cmd_name, cmd_args), ...]
Raises ConnectionError if the connection dies.
or ProtocolError if parsing of a command fails.
"""
assert self.connected
data = ''
try:
data = self.sock.recv(size)
except socket.error, exc:
if exc.args[0] == errno.EWOULDBLOCK:
return
if exc.args[0] == errno.ECONNRESET:
data = None
else:
raise
if not data:
self.mark_dead()
raise self.ConnectionError("connection died")
self.in_buffer += data
commands = []
while len(self.in_buffer) >= 12:
func, args, cmd_len = parse_command(self.in_buffer)
if not cmd_len:
break
commands.append((func, args))
self.in_buffer = buffer(self.in_buffer, cmd_len)
return commands
def send(self):
assert self.connected
if len(self.out_buffer) == 0:
return 0
try:
nsent = self.sock.send(self.out_buffer)
except socket.error, exc:
if exc.args[0] == errno.EWOULDBLOCK:
return len(self.out_buffer)
self.mark_dead()
raise self.ConnectionError(str(exc))
self.out_buffer = buffer(self.out_buffer, nsent)
return len(self.out_buffer)
def send_command(self, name, kwargs={}):
pkt = pack_command(name, **kwargs)
self.out_buffer += pkt
self.send()
def flush(self, timeout=None): # TODO: handle connection failures
while self.writable():
try:
wr_list = select.select([], [self], [], timeout)[1] # TODO: exc list
except select.error, exc:
# Ignore interrupted system call, reraise anything else
if exc[0] != 4:
raise
if self in wr_list:
self.send()
def send_command_blocking(self, cmd_name, cmd_args={}, timeout=None):
self.send_command(cmd_name, cmd_args)
self.flush(timeout)
def recv_blocking(self, timeout=None):
if not hasattr(self, '_command_queue'):
self._command_queue = []
if timeout:
end_time = time() + timeout
while not self._command_queue:
time_left = timeout and end_time - time() or 0.5
try:
rd_list, wr_list, ex_list = select.select([self], self.writable() and [self] or [], [self], time_left)
except select.error, exc:
# Ignore interrupted system call, reraise anything else
if exc[0] != 4:
raise
rd_list = wr_list = ex_list = []
if self in ex_list:
self.mark_dead()
raise self.ConnectionError("connection died")
if self in rd_list:
for cmd in self.recv():
self._command_queue.insert(0, cmd)
if self in wr_list:
self.send()
if time_left <= 0:
break
if self._command_queue:
return self._command_queue.pop()
return None
def close(self):
self.connected = False
try:
self.sock.close()
except:
pass
self.sock = None
def mark_dead(self):
self.close()
self.is_dead = True
def __repr__(self):
return ("<GearmanConnection %s:%d connected=%s dead=%s>" %
(self.addr[0], self.addr[1], self.connected, self.is_dead))