| OLD | NEW |
|---|
| (Empty) |
| 1 # -*- test-case-name: twisted.names.test.test_srvconnect -*- | |
| 2 # Copyright (c) 2001-2007 Twisted Matrix Laboratories. | |
| 3 # See LICENSE for details. | |
| 4 | |
| 5 import random | |
| 6 | |
| 7 from zope.interface import implements | |
| 8 | |
| 9 from twisted.internet import error, interfaces | |
| 10 | |
| 11 from twisted.names import client, dns | |
| 12 from twisted.names.error import DNSNameError | |
| 13 | |
| 14 class _SRVConnector_ClientFactoryWrapper: | |
| 15 def __init__(self, connector, wrappedFactory): | |
| 16 self.__connector = connector | |
| 17 self.__wrappedFactory = wrappedFactory | |
| 18 | |
| 19 def startedConnecting(self, connector): | |
| 20 self.__wrappedFactory.startedConnecting(self.__connector) | |
| 21 | |
| 22 def clientConnectionFailed(self, connector, reason): | |
| 23 self.__connector.connectionFailed(reason) | |
| 24 | |
| 25 def clientConnectionLost(self, connector, reason): | |
| 26 self.__connector.connectionLost(reason) | |
| 27 | |
| 28 def __getattr__(self, key): | |
| 29 return getattr(self.__wrappedFactory, key) | |
| 30 | |
| 31 class SRVConnector: | |
| 32 """A connector that looks up DNS SRV records. See RFC2782.""" | |
| 33 | |
| 34 implements(interfaces.IConnector) | |
| 35 | |
| 36 stopAfterDNS=0 | |
| 37 | |
| 38 def __init__(self, reactor, service, domain, factory, | |
| 39 protocol='tcp', connectFuncName='connectTCP', | |
| 40 connectFuncArgs=(), | |
| 41 connectFuncKwArgs={}, | |
| 42 ): | |
| 43 self.reactor = reactor | |
| 44 self.service = service | |
| 45 self.domain = domain | |
| 46 self.factory = factory | |
| 47 | |
| 48 self.protocol = protocol | |
| 49 self.connectFuncName = connectFuncName | |
| 50 self.connectFuncArgs = connectFuncArgs | |
| 51 self.connectFuncKwArgs = connectFuncKwArgs | |
| 52 | |
| 53 self.connector = None | |
| 54 self.servers = None | |
| 55 self.orderedServers = None # list of servers already used in this round | |
| 56 | |
| 57 def connect(self): | |
| 58 """Start connection to remote server.""" | |
| 59 self.factory.doStart() | |
| 60 self.factory.startedConnecting(self) | |
| 61 | |
| 62 if not self.servers: | |
| 63 if self.domain is None: | |
| 64 self.connectionFailed(error.DNSLookupError("Domain is not define
d.")) | |
| 65 return | |
| 66 d = client.lookupService('_%s._%s.%s' % (self.service, | |
| 67 self.protocol, | |
| 68 self.domain)) | |
| 69 d.addCallbacks(self._cbGotServers, self._ebGotServers) | |
| 70 d.addCallback(lambda x, self=self: self._reallyConnect()) | |
| 71 d.addErrback(self.connectionFailed) | |
| 72 elif self.connector is None: | |
| 73 self._reallyConnect() | |
| 74 else: | |
| 75 self.connector.connect() | |
| 76 | |
| 77 def _ebGotServers(self, failure): | |
| 78 failure.trap(DNSNameError) | |
| 79 | |
| 80 # Some DNS servers reply with NXDOMAIN when in fact there are | |
| 81 # just no SRV records for that domain. Act as if we just got an | |
| 82 # empty response and use fallback. | |
| 83 | |
| 84 self.servers = [] | |
| 85 self.orderedServers = [] | |
| 86 | |
| 87 def _cbGotServers(self, (answers, auth, add)): | |
| 88 if len(answers) == 1 and answers[0].type == dns.SRV \ | |
| 89 and answers[0].payload \ | |
| 90 and answers[0].payload.target == dns.Name('.'): | |
| 91 # decidedly not available | |
| 92 raise error.DNSLookupError("Service %s not available for domain %s." | |
| 93 % (repr(self.service), repr(self.domain))
) | |
| 94 | |
| 95 self.servers = [] | |
| 96 self.orderedServers = [] | |
| 97 for a in answers: | |
| 98 if a.type != dns.SRV or not a.payload: | |
| 99 continue | |
| 100 | |
| 101 self.orderedServers.append((a.payload.priority, a.payload.weight, | |
| 102 str(a.payload.target), a.payload.port)) | |
| 103 | |
| 104 def _serverCmp(self, a, b): | |
| 105 if a[0]!=b[0]: | |
| 106 return cmp(a[0], b[0]) | |
| 107 else: | |
| 108 return cmp(a[1], b[1]) | |
| 109 | |
| 110 def pickServer(self): | |
| 111 assert self.servers is not None | |
| 112 assert self.orderedServers is not None | |
| 113 | |
| 114 if not self.servers and not self.orderedServers: | |
| 115 # no SRV record, fall back.. | |
| 116 return self.domain, self.service | |
| 117 | |
| 118 if not self.servers and self.orderedServers: | |
| 119 # start new round | |
| 120 self.servers = self.orderedServers | |
| 121 self.orderedServers = [] | |
| 122 | |
| 123 assert self.servers | |
| 124 | |
| 125 self.servers.sort(self._serverCmp) | |
| 126 minPriority=self.servers[0][0] | |
| 127 | |
| 128 weightIndex = zip(xrange(len(self.servers)), [x[1] for x in self.servers | |
| 129 if x[0]==minPriority]) | |
| 130 weightSum = reduce(lambda x, y: (None, x[1]+y[1]), weightIndex, (None, 0
))[1] | |
| 131 rand = random.randint(0, weightSum) | |
| 132 | |
| 133 for index, weight in weightIndex: | |
| 134 weightSum -= weight | |
| 135 if weightSum <= 0: | |
| 136 chosen = self.servers[index] | |
| 137 del self.servers[index] | |
| 138 self.orderedServers.append(chosen) | |
| 139 | |
| 140 p, w, host, port = chosen | |
| 141 return host, port | |
| 142 | |
| 143 raise RuntimeError, 'Impossible %s pickServer result.' % self.__class__.
__name__ | |
| 144 | |
| 145 def _reallyConnect(self): | |
| 146 if self.stopAfterDNS: | |
| 147 self.stopAfterDNS=0 | |
| 148 return | |
| 149 | |
| 150 self.host, self.port = self.pickServer() | |
| 151 assert self.host is not None, 'Must have a host to connect to.' | |
| 152 assert self.port is not None, 'Must have a port to connect to.' | |
| 153 | |
| 154 connectFunc = getattr(self.reactor, self.connectFuncName) | |
| 155 self.connector=connectFunc( | |
| 156 self.host, self.port, | |
| 157 _SRVConnector_ClientFactoryWrapper(self, self.factory), | |
| 158 *self.connectFuncArgs, **self.connectFuncKwArgs) | |
| 159 | |
| 160 def stopConnecting(self): | |
| 161 """Stop attempting to connect.""" | |
| 162 if self.connector: | |
| 163 self.connector.stopConnecting() | |
| 164 else: | |
| 165 self.stopAfterDNS=1 | |
| 166 | |
| 167 def disconnect(self): | |
| 168 """Disconnect whatever our are state is.""" | |
| 169 if self.connector is not None: | |
| 170 self.connector.disconnect() | |
| 171 else: | |
| 172 self.stopConnecting() | |
| 173 | |
| 174 def getDestination(self): | |
| 175 assert self.connector | |
| 176 return self.connector.getDestination() | |
| 177 | |
| 178 def connectionFailed(self, reason): | |
| 179 self.factory.clientConnectionFailed(self, reason) | |
| 180 self.factory.doStop() | |
| 181 | |
| 182 def connectionLost(self, reason): | |
| 183 self.factory.clientConnectionLost(self, reason) | |
| 184 self.factory.doStop() | |
| 185 | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 12261012:
Remove third_party/twisted_8_1 (Closed)
Base URL: svn://svn.chromium.org/chrome/trunk/tools/build