如何设置ProxyAgent的超时时间？

Question

The client.Agent class has a connection timeout argument:

agent = client.Agent(reactor, connectTimeout=timeout, pool=pool)

How can this timeout be set when using client.ProxyAgent ?

auth = base64.b64encode("%s:%s" % (username, password))
headers['Proxy-Authorization'] = ["Basic " + auth.strip()]
endpoint = endpoints.TCP4ClientEndpoint(reactor, host, port)
agent = client.ProxyAgent(endpoint, reactor=reactor, pool=pool)

Answer 1

The TCP4ClientEndpoint you pass to ProxyAgent can be initialized with a timeout.

auth = base64.b64encode("%s:%s" % (username, password))
headers['Proxy-Authorization'] = ["Basic " + auth.strip()]
endpoint = endpoints.TCP4ClientEndpoint(reactor, host, port, timeout=yourTimeout)
agent = client.ProxyAgent(endpoint, reactor=reactor, pool=pool)

This is supposing you want to set the timeout for connecting to the proxy. If you wanted to set the timeout used by the proxy to connect to the upstream HTTP server, you can't control this.

Answer 2

It looks like client.ProxyAgent doesn't have a connectTimeout property:

class ProxyAgent(_AgentBase):
    """
    An HTTP agent able to cross HTTP proxies.

    @ivar _proxyEndpoint: The endpoint used to connect to the proxy.

    @since: 11.1
    """

    def __init__(self, endpoint, reactor=None, pool=None):
        if reactor is None:
            from twisted.internet import reactor
        _AgentBase.__init__(self, reactor, pool)
        self._proxyEndpoint = endpoint


    def request(self, method, uri, headers=None, bodyProducer=None):
        """
        Issue a new request via the configured proxy.
        """
        # Cache *all* connections under the same key, since we are only
        # connecting to a single destination, the proxy:
        key = ("http-proxy", self._proxyEndpoint)

        # To support proxying HTTPS via CONNECT, we will use key
        # ("http-proxy-CONNECT", scheme, host, port), and an endpoint that
        # wraps _proxyEndpoint with an additional callback to do the CONNECT.
        return self._requestWithEndpoint(key, self._proxyEndpoint, method,
                                         _URI.fromBytes(uri), headers,
                                         bodyProducer, uri)

ProxyAgent inherits from the same class Agent does ( _AgentBase ) and not from Agent itself.