snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

zerver/migrations/0782_delete_unused_anonymous_groups.py

@@ -0,0 +1,136 @@
+# Generated by Django 5.2.11 on 2026-02-24 06:39
+
+from django.db import connection, migrations, transaction
+from django.db.backends.base.schema import BaseDatabaseSchemaEditor
+from django.db.migrations.state import StateApps
+from psycopg2.sql import SQL, Literal
+
+
+def delete_unused_anonymous_groups(
+    apps: StateApps, schema_editor: BaseDatabaseSchemaEditor
+) -> None:
+    Realm = apps.get_model("zerver", "Realm")
+
+    query = """
+        WITH user_group_ids AS (
+            SELECT table_cols.value
+            FROM zerver_stream
+            CROSS JOIN LATERAL (
+                VALUES
+                    (can_add_subscribers_group_id),
+                    (can_administer_channel_group_id),
+                    (can_create_topic_group_id),
+                    (can_delete_any_message_group_id),
+                    (can_delete_own_message_group_id),
+                    (can_move_messages_out_of_channel_group_id),
+                    (can_move_messages_within_channel_group_id),
+                    (can_remove_subscribers_group_id),
+                    (can_send_message_group_id),
+                    (can_subscribe_group_id),
+                    (can_resolve_topics_group_id)
+            ) AS table_cols(value)
+            WHERE realm_id = %s
+
+            UNION ALL
+
+            SELECT table_cols.value
+            FROM zerver_namedusergroup
+            CROSS JOIN LATERAL (
+                VALUES
+                    (can_add_members_group_id),
+                    (can_join_group_id),
+                    (can_leave_group_id),
+                    (can_manage_group_id),
+                    (can_mention_group_id),
+                    (can_remove_members_group_id)
+            ) AS table_cols(value)
+            WHERE realm_id = %s
+
+            UNION ALL
+
+            SELECT realm_cols.value
+            FROM zerver_realm
+            CROSS JOIN LATERAL (
+                VALUES
+                    (create_multiuse_invite_group_id),
+                    (can_access_all_users_group_id),
+                    (can_add_subscribers_group_id),
+                    (can_add_custom_emoji_group_id),
+                    (can_create_bots_group_id),
+                    (can_create_groups_id),
+                    (can_create_public_channel_group_id),
+                    (can_create_private_channel_group_id),
+                    (can_create_web_public_channel_group_id),
+                    (can_create_write_only_bots_group_id),
+                    (can_delete_any_message_group_id),
+                    (can_delete_own_message_group_id),
+                    (can_invite_users_group_id),
+                    (can_manage_all_groups_id),
+                    (can_manage_billing_group_id),
+                    (can_mention_many_users_group_id),
+                    (can_move_messages_between_channels_group_id),
+                    (can_move_messages_between_topics_group_id),
+                    (can_resolve_topics_group_id),
+                    (can_set_delete_message_policy_group_id),
+                    (can_set_topics_policy_group_id),
+                    (can_summarize_topics_group_id),
+                    (direct_message_initiator_group_id),
+                    (direct_message_permission_group_id)
+            ) AS realm_cols(value)
+            WHERE id = %s
+        )
+
+        SELECT ug.id
+        FROM zerver_usergroup ug
+        LEFT JOIN zerver_namedusergroup ng
+          ON ng.usergroup_ptr_id = ug.id
+        WHERE ug.realm_id = %s
+          AND ng.usergroup_ptr_id IS NULL
+
+        EXCEPT
+
+        SELECT value FROM user_group_ids
+    """
+
+    BATCH_SIZE = 1000
+
+    with connection.cursor() as cursor:
+        for realm_id in Realm.objects.values_list("id", flat=True).iterator():
+            cursor.execute(query, [realm_id, realm_id, realm_id, realm_id])
+            unused_ids = [row[0] for row in cursor.fetchall()]
+
+            while unused_ids:
+                unused_id_str = SQL(",").join(map(Literal, unused_ids[:BATCH_SIZE]))
+                unused_ids = unused_ids[BATCH_SIZE:]
+                with transaction.atomic():
+                    cursor.execute(
+                        SQL(
+                            "DELETE FROM zerver_usergroupmembership WHERE user_group_id IN ({unused_ids})"
+                        ).format(unused_ids=unused_id_str)
+                    )
+                    cursor.execute(
+                        SQL(
+                            "DELETE FROM zerver_groupgroupmembership WHERE supergroup_id IN ({unused_ids})"
+                        ).format(unused_ids=unused_id_str)
+                    )
+                    cursor.execute(
+                        SQL("DELETE FROM zerver_usergroup WHERE id IN ({unused_ids})").format(
+                            unused_ids=unused_id_str
+                        )
+                    )
+
+
+class Migration(migrations.Migration):
+    atomic = False
+
+    dependencies = [
+        ("zerver", "0781_realm_image_thumbnail_size"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            delete_unused_anonymous_groups,
+            reverse_code=migrations.RunPython.noop,
+            elidable=True,
+        ),
+    ]