diff options
| -rw-r--r-- | synapse/handlers/sync.py | 16 | ||||
| -rw-r--r-- | synapse/rest/client/v2_alpha/sync.py | 3 | ||||
| -rw-r--r-- | synapse/util/caches/response_cache.py | 46 |
3 files changed, 64 insertions, 1 deletions
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: diff --git a/synapse/rest/client/v2_alpha/sync.py b/synapse/rest/client/v2_alpha/sync.py index de4a020ad4..c5785d7074 100644 --- a/synapse/rest/client/v2_alpha/sync.py +++ b/synapse/rest/client/v2_alpha/sync.py @@ -115,6 +115,8 @@ class SyncRestServlet(RestServlet): ) ) + request_key = (user, timeout, since, filter_id, full_state) + if filter_id: if filter_id.startswith('{'): try: @@ -134,6 +136,7 @@ class SyncRestServlet(RestServlet): user=user, filter_collection=filter, is_guest=requester.is_guest, + request_key=request_key, ) if since is not None: diff --git a/synapse/util/caches/response_cache.py b/synapse/util/caches/response_cache.py new file mode 100644 index 0000000000..1c2e344269 --- /dev/null +++ b/synapse/util/caches/response_cache.py @@ -0,0 +1,46 @@ +# -*- coding: utf-8 -*- +# Copyright 2016 OpenMarket Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from synapse.util.async import ObservableDeferred + + +class ResponseCache(object): + """ + This caches a deferred response. Until the deferred completes it will be + returned from the cache. This means that if the client retries the request + while the response is still being computed, that original response will be + used rather than trying to compute a new response. + """ + + def __init__(self): + self.pending_result_cache = {} # Request that haven't finished yet. + + def get(self, key): + result = self.pending_result_cache.get(key) + if result is not None: + return result.observe() + else: + return None + + def set(self, key, deferred): + result = ObservableDeferred(deferred) + self.pending_result_cache[key] = result + + def remove(r): + self.pending_result_cache.pop(key, None) + return r + + result.addBoth(remove) + return result.observe() |