Add a cache for getting the presence list for a user

synapse/handlers/presence.py

@@ -521,20 +521,26 @@ class PresenceHandler(BaseHandler):
         if not self.hs.is_mine(observer_user):
             raise SynapseError(400, "User is not hosted on this Home Server")
 
-        presence = yield self.store.get_presence_list(
+        presence_list = yield self.store.get_presence_list(
             observer_user.localpart, accepted=accepted
         )
 
-        for p in presence:
-            observed_user = UserID.from_string(p.pop("observed_user_id"))
-            p["observed_user"] = observed_user
-            p.update(self._get_or_offline_usercache(observed_user).get_state())
-            if "last_active" in p:
-                p["last_active_ago"] = int(
-                    self.clock.time_msec() - p.pop("last_active")
+        results = []
+        for row in presence_list:
+            observed_user = UserID.from_string(row["observed_user_id"])
+            result = {
+                "observed_user": observed_user, "accepted": row["accepted"]
+            }
+            result.update(
+                self._get_or_offline_usercache(observed_user).get_state()
+            )
+            if "last_active" in result:
+                result["last_active_ago"] = int(
+                    self.clock.time_msec() - result.pop("last_active")
                 )
+            results.append(result)
 
-        defer.returnValue(presence)
+        defer.returnValue(results)
 
     @defer.inlineCallbacks
     @log_function

synapse/storage/presence.py

@@ -13,7 +13,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from ._base import SQLBaseStore
+from ._base import SQLBaseStore, cached
+
+from twisted.internet import defer
 
 
 class PresenceStore(SQLBaseStore):
@@ -87,31 +89,48 @@ class PresenceStore(SQLBaseStore):
             desc="add_presence_list_pending",
         )
 
+    @defer.inlineCallbacks
     def set_presence_list_accepted(self, observer_localpart, observed_userid):
-        return self._simple_update_one(
+        result = yield self._simple_update_one(
             table="presence_list",
             keyvalues={"user_id": observer_localpart,
                        "observed_user_id": observed_userid},
             updatevalues={"accepted": True},
             desc="set_presence_list_accepted",
         )
+        self.get_presence_list_accepted.invalidate(observer_localpart)
+        defer.returnValue(result)
 
     def get_presence_list(self, observer_localpart, accepted=None):
-        keyvalues = {"user_id": observer_localpart}
-        if accepted is not None:
-            keyvalues["accepted"] = accepted
+        if accepted:
+            return self.get_presence_list_accepted(observer_localpart)
+        else:
+            keyvalues = {"user_id": observer_localpart}
+            if accepted is not None:
+                keyvalues["accepted"] = accepted
 
+            return self._simple_select_list(
+                table="presence_list",
+                keyvalues=keyvalues,
+                retcols=["observed_user_id", "accepted"],
+                desc="get_presence_list",
+            )
+
+    @cached()
+    def get_presence_list_accepted(self, observer_localpart):
         return self._simple_select_list(
             table="presence_list",
-            keyvalues=keyvalues,
+            keyvalues={"user_id": observer_localpart, "accepted": True},
             retcols=["observed_user_id", "accepted"],
-            desc="get_presence_list",
+            desc="get_presence_list_accepted",
         )
 
+    @defer.inlineCallbacks
     def del_presence_list(self, observer_localpart, observed_userid):
-        return self._simple_delete_one(
+        yield self._simple_delete_one(
             table="presence_list",
             keyvalues={"user_id": observer_localpart,
                        "observed_user_id": observed_userid},
             desc="del_presence_list",
         )
+        self.get_presence_list_accepted.invalidate(observer_localpart)