/
poetry-proxy.py
143 lines (89 loc) · 3.4 KB
/
poetry-proxy.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
# This is the Twisted Poetry Proxy, version 1.0
import optparse
from twisted.internet.defer import Deferred, maybeDeferred
from twisted.internet.protocol import ClientFactory, ServerFactory, Protocol
def parse_args():
usage = """usage: %prog [options] [hostname]:port
This is the Poetry Proxy, version 1.0.
python poetry-proxy.py [hostname]:port
If you are in the base directory of the twisted-intro package,
you could run it like this:
python twisted-server-1/poetry-proxy.py 10000
to proxy the poem for the server running on port 10000.
"""
parser = optparse.OptionParser(usage)
help = "The port to listen on. Default to a random available port."
parser.add_option('--port', type='int', help=help)
help = "The interface to listen on. Default is localhost."
parser.add_option('--iface', help=help, default='localhost')
options, args = parser.parse_args()
if len(args) != 1:
parser.error('Provide exactly one server address.')
def parse_address(addr):
if ':' not in addr:
host = '127.0.0.1'
port = addr
else:
host, port = addr.split(':', 1)
if not port.isdigit():
parser.error('Ports must be integers.')
return host, int(port)
return options, parse_address(args[0])
class PoetryProxyProtocol(Protocol):
def connectionMade(self):
d = maybeDeferred(self.factory.service.get_poem)
d.addCallback(self.transport.write)
d.addBoth(lambda r: self.transport.loseConnection())
class PoetryProxyFactory(ServerFactory):
protocol = PoetryProxyProtocol
def __init__(self, service):
self.service = service
class PoetryClientProtocol(Protocol):
poem = b''
def dataReceived(self, data):
self.poem += data
def connectionLost(self, reason):
self.poemReceived(self.poem)
def poemReceived(self, poem):
self.factory.poem_finished(poem)
class PoetryClientFactory(ClientFactory):
protocol = PoetryClientProtocol
def __init__(self):
self.deferred = Deferred()
def poem_finished(self, poem):
if self.deferred is not None:
d, self.deferred = self.deferred, None
d.callback(poem)
def clientConnectionFailed(self, connector, reason):
if self.deferred is not None:
d, self.deferred = self.deferred, None
d.errback(reason)
class ProxyService(object):
poem = None # the cached poem
def __init__(self, host, port):
self.host = host
self.port = port
def get_poem(self):
if self.poem is not None:
print('Using cached poem.')
return self.poem
print('Fetching poem from server.')
factory = PoetryClientFactory()
factory.deferred.addCallback(self.set_poem)
from twisted.internet import reactor
reactor.connectTCP(self.host, self.port, factory)
return factory.deferred
def set_poem(self, poem):
self.poem = poem
return poem
def main():
options, server_addr = parse_args()
service = ProxyService(*server_addr)
factory = PoetryProxyFactory(service)
from twisted.internet import reactor
port = reactor.listenTCP(options.port or 0, factory,
interface=options.iface)
print('Proxying %s on %s.' % (server_addr, port.getHost()))
reactor.run()
if __name__ == '__main__':
main()