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

zerver/lib/stream_topic.py

@@ -0,0 +1,37 @@
+from zerver.models import UserTopic
+
+
+class StreamTopicTarget:
+    """
+    This class is designed to help us move to a
+    StreamTopic table or something similar.  It isolates
+    places where we are still using `topic_name` as
+    a key into tables.
+    """
+
+    def __init__(self, stream_id: int, topic_name: str) -> None:
+        self.stream_id = stream_id
+        self.topic_name = topic_name
+
+    def user_ids_with_visibility_policy(self, visibility_policy: int) -> set[int]:
+        query = UserTopic.objects.filter(
+            stream_id=self.stream_id,
+            topic_name__iexact=self.topic_name,
+            visibility_policy=visibility_policy,
+        ).values(
+            "user_profile_id",
+        )
+        return {row["user_profile_id"] for row in query}
+
+    def user_id_to_visibility_policy_dict(self) -> dict[int, int]:
+        user_id_to_visibility_policy: dict[int, int] = {}
+
+        query = UserTopic.objects.filter(
+            stream_id=self.stream_id, topic_name__iexact=self.topic_name
+        ).values(
+            "visibility_policy",
+            "user_profile_id",
+        )
+        for row in query:
+            user_id_to_visibility_policy[row["user_profile_id"]] = row["visibility_policy"]
+        return user_id_to_visibility_policy