merge develop pydoc for _get_state_for_groups

1 files changed, 27 insertions, 13 deletions

diff --git a/synapse/storage/receipts.py b/synapse/storage/receipts.py
index c93c228f6e..0ac665e967 100644
--- a/synapse/storage/receipts.py
+++ b/synapse/storage/receipts.py
@@ -14,17 +14,18 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from ._base import SQLBaseStore
-from .util.id_generators import StreamIdGenerator
-from synapse.util.caches.descriptors import cachedInlineCallbacks, cachedList, cached
-from synapse.util.caches.stream_change_cache import StreamChangeCache
+import abc
+import logging
+
+from canonicaljson import json
 
 from twisted.internet import defer
 
-import abc
-import logging
-import simplejson as json
+from synapse.util.caches.descriptors import cached, cachedInlineCallbacks, cachedList
+from synapse.util.caches.stream_change_cache import StreamChangeCache
 
+from ._base import SQLBaseStore
+from .util.id_generators import StreamIdGenerator
 
 logger = logging.getLogger(__name__)
 
@@ -139,7 +140,9 @@ class ReceiptsWorkerStore(SQLBaseStore):
         """
         room_ids = set(room_ids)
 
-        if from_key:
+        if from_key is not None:
+            # Only ask the database about rooms where there have been new
+            # receipts added since `from_key`
             room_ids = yield self._receipts_stream_cache.get_entities_changed(
                 room_ids, from_key
             )
@@ -150,7 +153,6 @@ class ReceiptsWorkerStore(SQLBaseStore):
 
         defer.returnValue([ev for res in results.values() for ev in res])
 
-    @cachedInlineCallbacks(num_args=3, tree=True)
     def get_linearized_receipts_for_room(self, room_id, to_key, from_key=None):
         """Get receipts for a single room for sending to clients.
 
@@ -161,7 +163,19 @@ class ReceiptsWorkerStore(SQLBaseStore):
                 from the start.
 
         Returns:
-            list: A list of receipts.
+            Deferred[list]: A list of receipts.
+        """
+        if from_key is not None:
+            # Check the cache first to see if any new receipts have been added
+            # since`from_key`. If not we can no-op.
+            if not self._receipts_stream_cache.has_entity_changed(room_id, from_key):
+                defer.succeed([])
+
+        return self._get_linearized_receipts_for_room(room_id, to_key, from_key)
+
+    @cachedInlineCallbacks(num_args=3, tree=True)
+    def _get_linearized_receipts_for_room(self, room_id, to_key, from_key=None):
+        """See get_linearized_receipts_for_room
         """
         def f(txn):
             if from_key:
@@ -210,7 +224,7 @@ class ReceiptsWorkerStore(SQLBaseStore):
             "content": content,
         }])
 
-    @cachedList(cached_method_name="get_linearized_receipts_for_room",
+    @cachedList(cached_method_name="_get_linearized_receipts_for_room",
                 list_name="room_ids", num_args=3, inlineCallbacks=True)
     def _get_linearized_receipts_for_rooms(self, room_ids, to_key, from_key=None):
         if not room_ids:
@@ -372,7 +386,7 @@ class ReceiptsStore(ReceiptsWorkerStore):
             self.get_receipts_for_user.invalidate, (user_id, receipt_type)
         )
         # FIXME: This shouldn't invalidate the whole cache
-        txn.call_after(self.get_linearized_receipts_for_room.invalidate_many, (room_id,))
+        txn.call_after(self._get_linearized_receipts_for_room.invalidate_many, (room_id,))
 
         txn.call_after(
             self._receipts_stream_cache.entity_has_changed,
@@ -492,7 +506,7 @@ class ReceiptsStore(ReceiptsWorkerStore):
             self.get_receipts_for_user.invalidate, (user_id, receipt_type)
         )
         # FIXME: This shouldn't invalidate the whole cache
-        txn.call_after(self.get_linearized_receipts_for_room.invalidate_many, (room_id,))
+        txn.call_after(self._get_linearized_receipts_for_room.invalidate_many, (room_id,))
 
         self._simple_delete_txn(
             txn,