Use ObservableDeferreds instead of Deferreds as they behave as intended

2 files changed, 31 insertions, 30 deletions

diff --git a/synapse/rest/client/v1/room.py b/synapse/rest/client/v1/room.py
index caa779ffaf..47c4b84b73 100644
--- a/synapse/rest/client/v1/room.py
+++ b/synapse/rest/client/v1/room.py
@@ -22,6 +22,7 @@ from synapse.streams.config import PaginationConfig
 from synapse.api.constants import EventTypes, Membership
 from synapse.api.filtering import Filter
 from synapse.types import UserID, RoomID, RoomAlias
+from synapse.util.async import ObservableDeferred
 from synapse.events.utils import serialize_event, format_event_for_client_v2
 from synapse.http.servlet import (
     parse_json_object_from_request, parse_string, parse_integer
@@ -57,14 +58,14 @@ class RoomCreateRestServlet(ClientV1RestServlet):
     def on_PUT(self, request, txn_id):
         try:
             res_deferred = self.txns.get_client_transaction(request, txn_id)
-            res = yield res_deferred
+            res = yield res_deferred.observe()
             defer.returnValue(res)
         except KeyError:
             pass
 
-        res_deferred = self.on_POST(request)
+        res_deferred = ObservableDeferred(self.on_POST(request))
         self.txns.store_client_transaction(request, txn_id, res_deferred)
-        response = yield res_deferred
+        response = yield res_deferred.observe()
         defer.returnValue(response)
 
     @defer.inlineCallbacks
@@ -218,14 +219,14 @@ class RoomSendEventRestServlet(ClientV1RestServlet):
     def on_PUT(self, request, room_id, event_type, txn_id):
         try:
             res_deferred = self.txns.get_client_transaction(request, txn_id)
-            res = yield res_deferred
+            res = yield res_deferred.observe()
             defer.returnValue(res)
         except KeyError:
             pass
 
-        res_deferred = self.on_POST(request, room_id, event_type, txn_id)
+        res_deferred = ObservableDeferred(self.on_POST(request, room_id, event_type, txn_id))
         self.txns.store_client_transaction(request, txn_id, res_deferred)
-        response = yield res_deferred
+        response = yield res_deferred.observe()
         defer.returnValue(response)
 
 
@@ -287,14 +288,14 @@ class JoinRoomAliasServlet(ClientV1RestServlet):
     def on_PUT(self, request, room_identifier, txn_id):
         try:
             res_deferred = self.txns.get_client_transaction(request, txn_id)
-            res = yield res_deferred
+            res = yield res_deferred.observe()
             defer.returnValue(res)
         except KeyError:
             pass
 
-        res_deferred = self.on_POST(request, room_identifier, txn_id)
+        res_deferred = ObservableDeferred(self.on_POST(request, room_identifier, txn_id))
         self.txns.store_client_transaction(request, txn_id, res_deferred)
-        response = yield res_deferred
+        response = yield res_deferred.observe()
         defer.returnValue(response)
 
 
@@ -541,14 +542,14 @@ class RoomForgetRestServlet(ClientV1RestServlet):
     def on_PUT(self, request, room_id, txn_id):
         try:
             res_deferred = self.txns.get_client_transaction(request, txn_id)
-            res = yield res_deferred
+            res = yield res_deferred.observe()
             defer.returnValue(res)
         except KeyError:
             pass
 
-        res_deferred = self.on_POST(request, room_id, txn_id)
+        res_deferred = ObservableDeferred(self.on_POST(request, room_id, txn_id))
         self.txns.store_client_transaction(request, txn_id, res_deferred)
-        response = yield res_deferred
+        response = yield res_deferred.observe()
         defer.returnValue(response)
 
 
@@ -624,15 +625,15 @@ class RoomMembershipRestServlet(ClientV1RestServlet):
     @defer.inlineCallbacks
     def on_PUT(self, request, room_id, membership_action, txn_id):
         try:
-            res_deferred = self.txns.get_client_transaction(request, txn_id)
-            res = yield res_deferred
+            res_deferred = ObservableDeferred(self.txns.get_client_transaction(request, txn_id))
+            res = yield res_deferred.observe()
             defer.returnValue(res)
         except KeyError:
             pass
 
-        res_deferred = self.on_POST(request, room_id, membership_action, txn_id)
+        res_deferred = ObservableDeffself.on_POST(request, room_id, membership_action, txn_id)
         self.txns.store_client_transaction(request, txn_id, res_deferred)
-        response = yield res_deferred
+        response = yield res_deferred.observe()
         defer.returnValue(response)
 
 
@@ -669,14 +670,14 @@ class RoomRedactEventRestServlet(ClientV1RestServlet):
     def on_PUT(self, request, room_id, event_id, txn_id):
         try:
             res_deferred = self.txns.get_client_transaction(request, txn_id)
-            res = yield res_deferred
+            res = yield res_deferred.observe()
             defer.returnValue(res)
         except KeyError:
             pass
 
-        res_deferred = self.on_POST(request, room_id, event_id, txn_id)
+        res_deferred = ObservableDeferred(self.on_POST(request, room_id, event_id, txn_id))
         self.txns.store_client_transaction(request, txn_id, res_deferred)
-        response = yield res_deferred
+        response = yield res_deferred.observe()
         defer.returnValue(response)
 
 
diff --git a/synapse/rest/client/v1/transactions.py b/synapse/rest/client/v1/transactions.py
index f5012c5f59..774430458a 100644
--- a/synapse/rest/client/v1/transactions.py
+++ b/synapse/rest/client/v1/transactions.py
@@ -25,32 +25,32 @@ logger = logging.getLogger(__name__)
 class HttpTransactionCache(object):
 
     def __init__(self):
-        # { key : (txn_id, response_deferred) }
+        # { key : (txn_id, res_observ_defer) }
         self.transactions = {}
 
     def _get_response(self, key, txn_id):
         try:
-            (last_txn_id, response_deferred) = self.transactions[key]
+            (last_txn_id, res_observ_defer) = self.transactions[key]
             if txn_id == last_txn_id:
                 logger.info("get_response: Returning a response for %s", txn_id)
-                return response_deferred
+                return res_observ_defer
         except KeyError:
             pass
         return None
 
-    def _store_response(self, key, txn_id, response_deferred):
-        self.transactions[key] = (txn_id, response_deferred)
+    def _store_response(self, key, txn_id, res_observ_defer):
+        self.transactions[key] = (txn_id, res_observ_defer)
 
-    def store_client_transaction(self, request, txn_id, response_deferred):
+    def store_client_transaction(self, request, txn_id, res_observ_defer):
         """Stores the request/Promise<response> pair of an HTTP transaction.
 
         Args:
             request (twisted.web.http.Request): The twisted HTTP request. This
             request must have the transaction ID as the last path segment.
-            response_deferred (Promise<tuple>): A tuple of (response code, response dict)
+            res_observ_defer (Promise<tuple>): A tuple of (response code, response dict)
             txn_id (str): The transaction ID for this request.
         """
-        self._store_response(self._get_key(request), txn_id, response_deferred)
+        self._store_response(self._get_key(request), txn_id, res_observ_defer)
 
     def get_client_transaction(self, request, txn_id):
         """Retrieves a stored response if there was one.
@@ -64,10 +64,10 @@ class HttpTransactionCache(object):
         Raises:
             KeyError if the transaction was not found.
         """
-        response_deferred = self._get_response(self._get_key(request), txn_id)
-        if response_deferred is None:
+        res_observ_defer = self._get_response(self._get_key(request), txn_id)
+        if res_observ_defer is None:
             raise KeyError("Transaction not found.")
-        return response_deferred
+        return res_observ_defer
 
     def _get_key(self, request):
         token = get_access_token_from_request(request)