Clean up user_permissions view

- drop the "moderator OR admin" clauses from the view: we have triggers
  that already enforce admin-implies-moderator so the `OR admin` is
  pointless extra work.
- unify the sqlite and postgresql user_permissions view query: the
  postgresql syntax (with quoted "user" and specifying CROSS JOIN
  instead of JOIN) is perfectly acceptable for sqlite (and more correct
  anyway).

Author: jagerman

sogs/migrations/room_moderators.py

@@ -4,8 +4,10 @@
 
 def migrate(conn, *, check_only):
     """
-    Adds the room_moderators view and drops/replaces the user_permission_overrides_public_mods
-    index.
+    Adds the room_moderators view, along with a couple other optimizations that came at the same
+    time:
+    - we drop the user_permissions view (to be recreated in the user_permissions migration code)
+    - we drop the user_permission_overrides_public_mods index and recreate a tighter index
     """
 
     from .. import db
@@ -90,6 +92,7 @@ def migrate(conn, *, check_only):
 """
         )
 
+    conn.execute("DROP VIEW IF EXISTS user_permissions")
     conn.execute("DROP INDEX IF EXISTS user_permission_overrides_public_mods")
     conn.execute(
         "CREATE INDEX IF NOT EXISTS user_permission_overrides_mods "

sogs/migrations/user_permissions.py

@@ -17,13 +17,12 @@ def migrate(conn, *, check_only):
     if check_only:
         raise DatabaseUpgradeRequired("Recreate user_permissions view")
 
-    sqlite = db.engine.name == "sqlite"
     conn.execute(
-        f"""
+        """
 CREATE VIEW user_permissions AS
 SELECT
     rooms.id AS room,
-    users.id AS {'user' if sqlite else '"user"'},
+    users.id AS "user",
     users.session_id,
     CASE WHEN users.banned THEN TRUE ELSE COALESCE(user_permission_overrides.banned, FALSE) END AS banned,
     CASE WHEN users.moderator THEN TRUE ELSE COALESCE(user_permission_overrides.read, rooms.read) END AS read,
@@ -33,19 +32,19 @@ def migrate(conn, *, check_only):
     CASE WHEN users.moderator THEN TRUE ELSE COALESCE(user_permission_overrides.moderator, FALSE) END AS moderator,
     CASE WHEN users.admin THEN TRUE ELSE COALESCE(user_permission_overrides.admin, FALSE) END AS admin,
     -- room_moderator will be TRUE if the user is specifically listed as a moderator of the room
-    COALESCE(user_permission_overrides.moderator OR user_permission_overrides.admin, FALSE) AS room_moderator,
+    COALESCE(user_permission_overrides.moderator, FALSE) AS room_moderator,
     -- global_moderator will be TRUE if the user is a global moderator/admin (note that this is
     -- *not* exclusive of room_moderator: a moderator/admin could be listed in both).
-    COALESCE(users.moderator OR users.admin, FALSE) as global_moderator,
+    users.moderator as global_moderator,
     -- visible_mod will be TRUE if this mod is a publicly viewable moderator of the room
     CASE
-        WHEN user_permission_overrides.moderator OR user_permission_overrides.admin THEN user_permission_overrides.visible_mod
-        WHEN users.moderator OR users.admin THEN users.visible_mod
+        WHEN user_permission_overrides.moderator THEN user_permission_overrides.visible_mod
+        WHEN users.moderator THEN users.visible_mod
         ELSE FALSE
     END AS visible_mod
 FROM
-    users {'JOIN' if sqlite else 'CROSS JOIN'} rooms LEFT OUTER JOIN user_permission_overrides ON
-        (users.id = user_permission_overrides.{'user' if sqlite else '"user"'} AND rooms.id = user_permission_overrides.room)
+    users CROSS JOIN rooms LEFT OUTER JOIN user_permission_overrides ON
+        (users.id = user_permission_overrides."user" AND rooms.id = user_permission_overrides.room)
 """  # noqa E501
     )
 

sogs/schema.pgsql

@@ -374,14 +374,14 @@ SELECT
     CASE WHEN users.moderator THEN TRUE ELSE COALESCE(user_permission_overrides.moderator, FALSE) END AS moderator,
     CASE WHEN users.admin THEN TRUE ELSE COALESCE(user_permission_overrides.admin, FALSE) END AS admin,
     -- room_moderator will be TRUE if the user is specifically listed as a moderator of the room
-    COALESCE(user_permission_overrides.moderator OR user_permission_overrides.admin, FALSE) AS room_moderator,
+    COALESCE(user_permission_overrides.moderator, FALSE) AS room_moderator,
     -- global_moderator will be TRUE if the user is a global moderator/admin (note that this is
     -- *not* exclusive of room_moderator: a moderator/admin could be listed in both).
-    COALESCE(users.moderator OR users.admin, FALSE) as global_moderator,
+    users.moderator as global_moderator,
     -- visible_mod will be TRUE if this mod is a publicly viewable moderator of the room
     CASE
-        WHEN user_permission_overrides.moderator OR user_permission_overrides.admin THEN user_permission_overrides.visible_mod
-        WHEN users.moderator OR users.admin THEN users.visible_mod
+        WHEN user_permission_overrides.moderator THEN user_permission_overrides.visible_mod
+        WHEN users.moderator THEN users.visible_mod
         ELSE FALSE
     END AS visible_mod
 FROM

sogs/schema.sqlite

@@ -318,7 +318,7 @@ END;
 CREATE VIEW user_permissions AS
 SELECT
     rooms.id AS room,
-    users.id AS user,
+    users.id AS "user",
     users.session_id,
     CASE WHEN users.banned THEN TRUE ELSE COALESCE(user_permission_overrides.banned, FALSE) END AS banned,
     CASE WHEN users.moderator THEN TRUE ELSE COALESCE(user_permission_overrides.read, rooms.read) END AS read,
@@ -328,19 +328,19 @@ SELECT
     CASE WHEN users.moderator THEN TRUE ELSE COALESCE(user_permission_overrides.moderator, FALSE) END AS moderator,
     CASE WHEN users.admin THEN TRUE ELSE COALESCE(user_permission_overrides.admin, FALSE) END AS admin,
     -- room_moderator will be TRUE if the user is specifically listed as a moderator of the room
-    COALESCE(user_permission_overrides.moderator OR user_permission_overrides.admin, FALSE) AS room_moderator,
+    COALESCE(user_permission_overrides.moderator, FALSE) AS room_moderator,
     -- global_moderator will be TRUE if the user is a global moderator/admin (note that this is
     -- *not* exclusive of room_moderator: a moderator/admin could be listed in both).
-    COALESCE(users.moderator OR users.admin, FALSE) as global_moderator,
+    users.moderator as global_moderator,
     -- visible_mod will be TRUE if this mod is a publicly viewable moderator of the room
     CASE
-        WHEN user_permission_overrides.moderator OR user_permission_overrides.admin THEN user_permission_overrides.visible_mod
-        WHEN users.moderator OR users.admin THEN users.visible_mod
+        WHEN user_permission_overrides.moderator THEN user_permission_overrides.visible_mod
+        WHEN users.moderator THEN users.visible_mod
         ELSE FALSE
     END AS visible_mod
 FROM
-    users JOIN rooms LEFT OUTER JOIN user_permission_overrides ON
-        (users.id = user_permission_overrides.user AND rooms.id = user_permission_overrides.room);
+    users CROSS JOIN rooms LEFT OUTER JOIN user_permission_overrides ON
+        (users.id = user_permission_overrides."user" AND rooms.id = user_permission_overrides.room);
 
 -- Used to accesses the moderator list for a room.  This view is considerably faster than querying
 -- the `user_permissions` table for a list of all moderators.