Use txtorcon's new web_agent utilities.

This replaces our OnionRoutedAgent and txsocksx

Author: aagbsn

bwscanner/measurement.py

@@ -6,9 +6,9 @@
 from twisted.internet import defer
 
 from bwscanner.logger import log
-from bwscanner.attacher import SOCKSClientStreamAttacher
 from bwscanner.circuit import TwoHop
-from bwscanner.fetcher import OnionRoutedAgent, hashingReadBody
+from bwscanner.fetcher import OnionRoutedAgent
+from bwscanner.fetcher import get_tor_socks_endpoint, hashingReadBody
 from bwscanner.writer import ResultSink
 
 # defer.setDebugging(True)
@@ -31,6 +31,7 @@ def __init__(self, state, clock, measurement_dir, **kwargs):
         this_partition: which partition of circuit we will process
         """
         self.state = state
+        self._socks = None
         self.clock = clock
         self.measurement_dir = measurement_dir
         self.partitions = kwargs.get('partitions', 1)
@@ -55,9 +56,6 @@ def __init__(self, state, clock, measurement_dir, **kwargs):
 
         self.result_sink = ResultSink(self.measurement_dir, chunk_size=10)
 
-        # Add a stream attacher
-        self.state.set_attacher(SOCKSClientStreamAttacher(self.state), clock)
-
     def now(self):
         return time.time()
 
@@ -162,14 +160,16 @@ def gotResult(result):
                 return result
             deferred.addBoth(gotResult)
 
-        agent = OnionRoutedAgent(self.clock, path=path, state=self.state)
-        request = agent.request("GET", url)
-        request.addCallback(hashingReadBody)  # returns a readBody Deferred
-        timeoutDeferred(request, self.request_timeout)
-        request.addCallbacks(get_circuit_bw)
-        request.addErrback(circ_failure)
-        request.addCallback(self.result_sink.send)
-        return request
+        d = self.state.build_circuit(path, False)
+        d.addCallback(lambda c: c.when_built())
+        d.addCallback(lambda c: c.web_agent(self.clock, self.socks))
+        d.addCallback(lambda a: a.request("GET", url))
+        d.addCallback(hashingReadBody)
+        timeoutDeferred(d, self.request_timeout)
+        d.addCallbacks(get_circuit_bw)
+        d.addErrback(circ_failure)
+        d.addCallback(self.result_sink.send)
+        return d
 
     @defer.inlineCallbacks
     def get_r_ns_bw(self, router):
@@ -197,3 +197,10 @@ def get_r_desc_bw(self, router):
         defer.returnValue((server_descriptor.average_bandwidth,
                            server_descriptor.burst_bandwidth,
                            server_descriptor.observed_bandwidth))
+
+    @property
+    @defer.inlineCallbacks
+    def socks(self):
+        if self._socks is None:
+            self._socks = yield get_tor_socks_endpoint(self.state)
+        defer.returnValue(self._socks)