diff options
Diffstat (limited to 'synapse/handlers/sync.py')
| -rw-r--r-- | synapse/handlers/sync.py | 36 |
1 files changed, 26 insertions, 10 deletions
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py index 64f74d4c94..151484e21e 100644 --- a/synapse/handlers/sync.py +++ b/synapse/handlers/sync.py @@ -49,7 +49,7 @@ from synapse.types import ( from synapse.util.async_helpers import concurrently_execute from synapse.util.caches.expiringcache import ExpiringCache from synapse.util.caches.lrucache import LruCache -from synapse.util.caches.response_cache import ResponseCache +from synapse.util.caches.response_cache import ResponseCache, ResponseCacheContext from synapse.util.metrics import Measure, measure_func from synapse.visibility import filter_events_for_client @@ -84,12 +84,15 @@ LAZY_LOADED_MEMBERS_CACHE_MAX_AGE = 30 * 60 * 1000 LAZY_LOADED_MEMBERS_CACHE_MAX_SIZE = 100 +SyncRequestKey = Tuple[Any, ...] + + @attr.s(slots=True, frozen=True) class SyncConfig: user = attr.ib(type=UserID) filter_collection = attr.ib(type=FilterCollection) is_guest = attr.ib(type=bool) - request_key = attr.ib(type=Tuple[Any, ...]) + request_key = attr.ib(type=SyncRequestKey) device_id = attr.ib(type=Optional[str]) @@ -267,9 +270,9 @@ class SyncHandler: self.presence_handler = hs.get_presence_handler() self.event_sources = hs.get_event_sources() self.clock = hs.get_clock() - self.response_cache = ResponseCache( + self.response_cache: ResponseCache[SyncRequestKey] = ResponseCache( hs.get_clock(), "sync", timeout_ms=SYNC_RESPONSE_CACHE_MS - ) # type: ResponseCache[Tuple[Any, ...]] + ) self.state = hs.get_state_handler() self.auth = hs.get_auth() self.storage = hs.get_storage() @@ -308,6 +311,7 @@ class SyncHandler: since_token, timeout, full_state, + cache_context=True, ) logger.debug("Returning sync response for %s", user_id) return res @@ -315,9 +319,10 @@ class SyncHandler: async def _wait_for_sync_for_user( self, sync_config: SyncConfig, - since_token: Optional[StreamToken] = None, - timeout: int = 0, - full_state: bool = False, + since_token: Optional[StreamToken], + timeout: int, + full_state: bool, + cache_context: ResponseCacheContext[SyncRequestKey], ) -> SyncResult: if since_token is None: sync_type = "initial_sync" @@ -344,13 +349,13 @@ class SyncHandler: if timeout == 0 or since_token is None or full_state: # we are going to return immediately, so don't bother calling # notifier.wait_for_events. - result = await self.current_sync_for_user( + result: SyncResult = await self.current_sync_for_user( sync_config, since_token, full_state=full_state ) else: - def current_sync_callback(before_token, after_token): - return self.current_sync_for_user(sync_config, since_token) + async def current_sync_callback(before_token, after_token) -> SyncResult: + return await self.current_sync_for_user(sync_config, since_token) result = await self.notifier.wait_for_events( sync_config.user.to_string(), @@ -359,6 +364,17 @@ class SyncHandler: from_token=since_token, ) + # if nothing has happened in any of the users' rooms since /sync was called, + # the resultant next_batch will be the same as since_token (since the result + # is generated when wait_for_events is first called, and not regenerated + # when wait_for_events times out). + # + # If that happens, we mustn't cache it, so that when the client comes back + # with the same cache token, we don't immediately return the same empty + # result, causing a tightloop. (#8518) + if result.next_batch == since_token: + cache_context.should_cache = False + if result: if sync_config.filter_collection.lazy_load_members(): lazy_loaded = "true" |