1 files changed, 110 insertions, 1 deletions

diff --git a/synapse/storage/user_directory.py b/synapse/storage/user_directory.py
index 0123e28f99..2a17cbc9e9 100644
--- a/synapse/storage/user_directory.py
+++ b/synapse/storage/user_directory.py
@@ -273,17 +273,38 @@ class UserDirectoryStore(SQLBaseStore):
             desc="get_users_in_public_due_to_room",
         )
 
+    @defer.inlineCallbacks
     def get_users_in_dir_due_to_room(self, room_id):
         """Get all user_ids that are in the room directory becuase they're
         in the given room_id
         """
-        return self._simple_select_onecol(
+        user_ids_dir = yield self._simple_select_onecol(
             table="user_directory",
             keyvalues={"room_id": room_id},
             retcol="user_id",
             desc="get_users_in_dir_due_to_room",
         )
 
+        user_ids_pub = yield self._simple_select_onecol(
+            table="users_in_pubic_room",
+            keyvalues={"room_id": room_id},
+            retcol="user_id",
+            desc="get_users_in_dir_due_to_room",
+        )
+
+        user_ids_share = yield self._simple_select_onecol(
+            table="users_who_share_rooms",
+            keyvalues={"room_id": room_id},
+            retcol="user_id",
+            desc="get_users_in_dir_due_to_room",
+        )
+
+        user_ids = set(user_ids_dir)
+        user_ids.update(user_ids_pub)
+        user_ids.update(user_ids_share)
+
+        defer.returnValue(user_ids)
+
     @defer.inlineCallbacks
     def get_all_rooms(self):
         """Get all room_ids we've ever known about, in ascending order of "size"
@@ -398,6 +419,94 @@ class UserDirectoryStore(SQLBaseStore):
             "remove_user_who_share_room", _remove_user_who_share_room_txn
         )
 
+    @cached(max_entries=500000)
+    def get_if_users_share_a_room(self, user_id, other_user_id):
+        """Gets if users share a room.
+
+        Args:
+            user_id (str): Must be a local user_id
+            other_user_id (str)
+
+        Returns:
+            bool|None: None if they don't share a room, otherwise whether they
+            share a private room or not.
+        """
+        return self._simple_select_one_onecol(
+            table="users_who_share_rooms",
+            keyvalues={
+                "user_id": user_id,
+                "other_user_id": other_user_id,
+            },
+            retcol="share_private",
+            allow_none=True,
+        )
+
+    @cachedInlineCallbacks(max_entries=500000, iterable=True)
+    def get_users_who_share_room_from_dir(self, user_id):
+        """Returns the set of users who share a room with `user_id`
+
+        Args:
+            user_id(str): Must be a local user
+
+        Returns:
+            dict: user_id -> share_private mapping
+        """
+        rows = yield self._simple_select_list(
+            table="users_who_share_rooms",
+            keyvalues={
+                "user_id": user_id,
+            },
+            retcols=("other_user_id", "share_private",),
+            desc="get_users_who_share_room_with_user",
+        )
+
+        defer.returnValue({
+            row["other_user_id"]: row["share_private"]
+            for row in rows
+        })
+
+    def get_users_in_share_dir_with_room_id(self, user_id, room_id):
+        """Get all user tuples that are in the users_who_share_rooms due to the
+        given room_id.
+
+        Returns:
+            [(user_id, other_user_id)]: where one of the two will match the given
+            user_id.
+        """
+        sql = """
+            SELECT user_id, other_user_id FROM users_who_share_rooms
+            WHERE room_id = ? AND (user_id = ? OR other_user_id = ?)
+        """
+        return self._execute(
+            "get_users_in_share_dir_with_room_id", None, sql, room_id, user_id, user_id
+        )
+
+    @defer.inlineCallbacks
+    def get_rooms_in_common_for_users(self, user_id, other_user_id):
+        """Given two user_ids find out the list of rooms they share.
+        """
+        sql = """
+            SELECT room_id FROM (
+                SELECT c.room_id FROM current_state_events AS c
+                INNER JOIN room_memberships USING (event_id)
+                WHERE type = 'm.room.member'
+                    AND membership = 'join'
+                    AND state_key = ?
+            ) AS f1 INNER JOIN (
+                SELECT c.room_id FROM current_state_events AS c
+                INNER JOIN room_memberships USING (event_id)
+                WHERE type = 'm.room.member'
+                    AND membership = 'join'
+                    AND state_key = ?
+            ) f2 USING (room_id)
+        """
+
+        rows = yield self._execute(
+            "get_rooms_in_common_for_users", None, sql, user_id, other_user_id
+        )
+
+        defer.returnValue([room_id for room_id, in rows])
+
     def delete_all_from_user_dir(self):
         """Delete the entire user directory
         """