Merge pull request #668 from matrix-org/markjh/deduplicate

Deduplicate identical /sync requests

2 files changed, 26 insertions, 2 deletions

diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index d5c56ce0d6..133183a257 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -25,6 +25,7 @@ from synapse.api.constants import (
 from synapse.api.errors import AuthError, StoreError, SynapseError, Codes
 from synapse.util import stringutils, unwrapFirstError
 from synapse.util.logcontext import preserve_context_over_fn
+from synapse.util.caches.response_cache import ResponseCache
 
 from signedjson.sign import verify_signed_json
 from signedjson.key import decode_verify_key_bytes
@@ -939,9 +940,18 @@ class RoomMemberHandler(BaseHandler):
 
 
 class RoomListHandler(BaseHandler):
+    def __init__(self, hs):
+        super(RoomListHandler, self).__init__(hs)
+        self.response_cache = ResponseCache()
 
-    @defer.inlineCallbacks
     def get_public_room_list(self):
+        result = self.response_cache.get(())
+        if not result:
+            result = self.response_cache.set((), self._get_public_room_list())
+        return result
+
+    @defer.inlineCallbacks
+    def _get_public_room_list(self):
         room_ids = yield self.store.get_public_room_ids()
 
         @defer.inlineCallbacks
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 1f6fde8e8a..48ab5707e1 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -20,6 +20,7 @@ from synapse.api.constants import Membership, EventTypes
 from synapse.util import unwrapFirstError
 from synapse.util.logcontext import LoggingContext, preserve_fn
 from synapse.util.metrics import Measure
+from synapse.util.caches.response_cache import ResponseCache
 from synapse.push.clientformat import format_push_rules_for_user
 
 from twisted.internet import defer
@@ -35,6 +36,7 @@ SyncConfig = collections.namedtuple("SyncConfig", [
     "user",
     "filter_collection",
     "is_guest",
+    "request_key",
 ])
 
 
@@ -136,8 +138,8 @@ class SyncHandler(BaseHandler):
         super(SyncHandler, self).__init__(hs)
         self.event_sources = hs.get_event_sources()
         self.clock = hs.get_clock()
+        self.response_cache = ResponseCache()
 
-    @defer.inlineCallbacks
     def wait_for_sync_for_user(self, sync_config, since_token=None, timeout=0,
                                full_state=False):
         """Get the sync for a client if we have new data for it now. Otherwise
@@ -146,7 +148,19 @@ class SyncHandler(BaseHandler):
         Returns:
             A Deferred SyncResult.
         """
+        result = self.response_cache.get(sync_config.request_key)
+        if not result:
+            result = self.response_cache.set(
+                sync_config.request_key,
+                self._wait_for_sync_for_user(
+                    sync_config, since_token, timeout, full_state
+                )
+            )
+        return result
 
+    @defer.inlineCallbacks
+    def _wait_for_sync_for_user(self, sync_config, since_token, timeout,
+                                full_state):
         context = LoggingContext.current_context()
         if context:
             if since_token is None: