Merge pull request #231 from meejah/when_closed_when_built

When closed when built

test/test_circuit.py

@@ -399,7 +399,7 @@ def test_close_circuit(self):
         # we already pretended that Tor answered "OK" to the
         # CLOSECIRCUIT call (see close_circuit() in FakeTorController
         # above) however the circuit isn't "really" closed yet...
-        self.assertTrue(not d0.called)
+        self.assertTrue(not d0.result.called)
         # not unit-test-y? shouldn't probably delve into internals I
         # suppose...
         self.assertTrue(circuit._closing_deferred is not None)
@@ -463,6 +463,32 @@ def test_is_built(self):
         self.assertTrue(built1.result == circuit)
         self.assertTrue(built2.result == circuit)
 
+    def test_when_closed(self):
+        tor = FakeTorController()
+        a = FakeRouter('$E11D2B2269CC25E67CA6C9FB5843497539A74FD0', 'a')
+        b = FakeRouter('$50DD343021E509EB3A5A7FD0D8A4F8364AFBDCB5', 'b')
+        c = FakeRouter('$253DFF1838A2B7782BE7735F74E50090D46CA1BC', 'c')
+        tor.routers['$E11D2B2269CC25E67CA6C9FB5843497539A74FD0'] = a
+        tor.routers['$50DD343021E509EB3A5A7FD0D8A4F8364AFBDCB5'] = b
+        tor.routers['$253DFF1838A2B7782BE7735F74E50090D46CA1BC'] = c
+
+        circuit = Circuit(tor)
+        circuit.listen(tor)
+
+        circuit.update('123 EXTENDED $E11D2B2269CC25E67CA6C9FB5843497539A74FD0=eris,$50DD343021E509EB3A5A7FD0D8A4F8364AFBDCB5=venus,$253DFF1838A2B7782BE7735F74E50090D46CA1BC=chomsky PURPOSE=GENERAL'.split())
+        d0 = circuit.when_closed()
+
+        self.assertFalse(d0.called)
+
+        circuit.update('123 BUILT $E11D2B2269CC25E67CA6C9FB5843497539A74FD0=eris,$50DD343021E509EB3A5A7FD0D8A4F8364AFBDCB5=venus,$253DFF1838A2B7782BE7735F74E50090D46CA1BC=chomsky PURPOSE=GENERAL'.split())
+        circuit.update('123 CLOSED'.split())
+
+        d1 = circuit.when_closed()
+
+        self.assertTrue(d0 is not d1)
+        self.assertTrue(d0.called)
+        self.assertTrue(d1.called)
+
     def test_is_built_errback(self):
         tor = FakeTorController()
         a = FakeRouter('$E11D2B2269CC25E67CA6C9FB5843497539A74FD0', 'a')

txtorcon/circuit.py

@@ -16,7 +16,7 @@
 from zope.interface import implementer
 
 from .interface import IRouterContainer, IStreamAttacher
-from txtorcon.util import find_keywords, maybe_ip_addr
+from txtorcon.util import find_keywords, maybe_ip_addr, SingleObserver
 
 
 # look like "2014-01-25T02:12:14.593772"
@@ -211,8 +211,9 @@ def __init__(self, routercontainer):
         # caches parsed value for time_created()
         self._time_created = None
 
-        # all notifications for when_built
-        self._when_built = []
+        # all notifications for when_built, when_closed
+        self._when_built = SingleObserver()
+        self._when_closed = SingleObserver()
 
     # XXX backwards-compat for old .is_built for now
     @property
@@ -232,12 +233,18 @@ def when_built(self):
         Tor before it gets to BUILT) you will receive an errback
         """
         # XXX note to self: we never do an errback; fix this behavior
-        d = defer.Deferred()
         if self.state == 'BUILT':
-            d.callback(self)
-        else:
-            self._when_built.append(d)
-        return d
+            return defer.succeed(self)
+        return self._when_built.when_fired()
+
+    def when_closed(self):
+        """
+        Returns a Deferred that callback()'s (with this Circuit instance)
+        when this circuit hits CLOSED or FAILED.
+        """
+        if self.state in ['CLOSED', 'FAILED']:
+            return defer.succeed(self)
+        return self._when_closed.when_fired()
 
     def web_agent(self, reactor, socks_endpoint, pool=None):
         """
@@ -355,7 +362,7 @@ def close_command_is_queued(*args):
             return self._closing_deferred
         d = self._torstate.close_circuit(self.id, **kw)
         d.addCallback(close_command_is_queued)
-        return self._closing_deferred
+        return d
 
     def age(self, now=None):
         """
@@ -413,7 +420,7 @@ def update(self, args):
         if self.state == 'BUILT':
             for x in self.listeners:
                 x.circuit_built(self)
-            self._notify_when_built()
+            self._when_built.fire(self)
 
         elif self.state == 'CLOSED':
             if len(self.streams) > 0:
@@ -443,15 +450,6 @@ def update(self, args):
             for x in self.listeners:
                 x.circuit_failed(self, **flags)
 
-    # XXX should use the util helper
-    def _notify_when_built(self, err=None):
-        for d in self._when_built:
-            if err is None:
-                d.callback(self)
-            else:
-                d.errback(Failure(err))
-        self._when_built = []
-
     def maybe_call_closing_deferred(self):
         """
         Used internally to callback on the _closing_deferred if it
@@ -461,6 +459,7 @@ def maybe_call_closing_deferred(self):
         if self._closing_deferred:
             self._closing_deferred.callback(self)
             self._closing_deferred = None
+        self._when_closed.fire(self)
 
     def update_path(self, path):
         """

txtorcon/torstate.py

@@ -11,6 +11,7 @@
 import warnings
 
 from twisted.internet import defer
+from twisted.python.failure import Failure
 from twisted.internet.endpoints import TCP4ClientEndpoint
 from twisted.internet.endpoints import UNIXClientEndpoint
 from twisted.internet.interfaces import IReactorCore
@@ -920,23 +921,23 @@ def circuit_new(self, circuit):
     def circuit_destroy(self, circuit):
         "Used by circuit_closed and circuit_failed (below)"
         txtorlog.msg("circuit_destroy:", circuit.id)
-        circuit._notify_when_built(
-            Exception("Destroying circuit; will never hit BUILT")
+        circuit._when_built.fire(
+            Failure(Exception("Destroying circuit; will never hit BUILT"))
         )
         del self.circuits[circuit.id]
 
     def circuit_closed(self, circuit, **kw):
         "ICircuitListener API"
         txtorlog.msg("circuit_closed", circuit)
-        circuit._notify_when_built(
-            Exception("Circuit closed ('{}')".format(_extract_reason(kw)))
+        circuit._when_built.fire(
+            Failure(Exception("Circuit closed ('{}')".format(_extract_reason(kw))))
         )
         self.circuit_destroy(circuit)
 
     def circuit_failed(self, circuit, **kw):
         "ICircuitListener API"
         txtorlog.msg("circuit_failed", circuit, str(kw))
-        circuit._notify_when_built(
-            Exception("Circuit failed ('{}')".format(_extract_reason(kw)))
+        circuit._when_built.fire(
+            Failure(Exception("Circuit failed ('{}')".format(_extract_reason(kw))))
         )
         self.circuit_destroy(circuit)