我正在尝试在 AMP 客户端中链接延迟,如下所示:
客户:
from twisted.internet.endpoints import TCP4ClientEndpoint, connectProtocol
from twisted.protocols.amp import AMP
import commands
def connect_protocol(host, port):
destination = TCP4ClientEndpoint(reactor, host, port)
d = connectProtocol(destination, AMP())
def connect(protocol):
print 'Connecting to server as Mr Spaceman...'
return protocol.callRemote(commands.Connect,
username='Mr Foo')
def say(protocol):
print 'Saying "Hello world" to the server...'
return protocol.callRemote(commands.Say,
phrase='Hello world')
d.addCallback(connect)
d.addCallback(say)
def main(host, port):
connect_protocol(host, port)
print 'Connected to %s:%d...' % (host, port)
reactor.run()
main('127.0.0.1', 12345)
服务器:
from twisted.internet.protocol import Factory
from twisted.protocols.amp import AMP
import commands
class CommandProtocol(AMP):
def connect(self, username):
print "Received connect command: %s." % (username)
return {}
commands.Connect.responder(connect)
def say(self, phrase):
print "Received phrase \"%s\"." % phrase
return {}
commands.Say.responder(say)
def main(port):
factory = Factory()
factory.protocol = CommandProtocol
reactor.listenTCP(port, factory)
print 'Started AMP server on port %d...' % port
reactor.run()
main(12345)
只有 connect()
在服务器端被触发
最佳答案
首先,启用日志记录:
from sys import stdout
from twisted.python.log import startLogging
startLogging(stdout)
现在您将看到程序中发生了什么。
其次,至少有一个最终的 errback 来记录 Deferred
上未处理的故障,这样这些故障就会确定地显示出来,而不是依赖于垃圾收集器:
from twisted.python.log import err
...
d.addCallback(connect)
d.addCallback(say)
d.addErrback(err, "connect_protocol encountered some problem")
最后,Deferred 的结果会被附加的回调和 errback 改变。在这种情况下,传递给 say
的参数是 connect
返回的 Deferred
的结果。这与 connect
的参数不同,因此您不太可能在其上使用 callRemote
。
您可以通过多种不同的方式解决此问题。涉及最少代码更改的一种方法(但不一定是最佳解决方案)是将协议(protocol)作为 connect
Deferred
结果中的额外值传递:
def connect(protocol):
print 'Connecting to server as Mr Spaceman...'
d = protocol.callRemote(commands.Connect, username='Mr Foo')
d.addCallback(lambda result: (protocol, result))
return d
def say((protocol, result)):
print 'Saying "Hello world" to the server...'
return protocol.callRemote(commands.Say,
phrase='Hello world')
关于python - 链接延迟回调,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18244681/