backend_client.py 文件源码

def _request(self, method, urn, genReceiver, bodyProducer=None, retries=3):
        if self.backend_type == 'onion':
            agent = TrueHeadersSOCKS5Agent(reactor,
                                           proxyEndpoint=TCP4ClientEndpoint(reactor,
                                                                            '127.0.0.1',
                                                                            config.tor.socks_port))
        else:
            agent = Agent(reactor)

        attempts = 0

        finished = defer.Deferred()

        def perform_request(attempts):
            uri = urljoin(self.base_address, urn)
            d = agent.request(method, uri, bodyProducer=bodyProducer,
                              headers=Headers(self.base_headers))

            @d.addCallback
            def callback(response):
                try:
                    content_length = int(response.headers.getRawHeaders('content-length')[0])
                except:
                    content_length = None
                response.deliverBody(genReceiver(finished, content_length))

            def errback(err, attempts):
                # We we will recursively keep trying to perform a request until
                # we have reached the retry count.
                if attempts < retries:
                    log.err("Lookup {} failed. Retrying.".format(uri))
                    attempts += 1
                    perform_request(attempts)
                else:
                    log.err("Failed. Giving up.")
                    finished.errback(err)

            d.addErrback(errback, attempts)

        perform_request(attempts)

        return finished