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

zerver/lib/query_helpers.py

@@ -0,0 +1,30 @@
+from typing import TypeVar
+
+from django.db import models
+from django.db.models import QuerySet
+
+ModelT = TypeVar("ModelT", bound=models.Model)
+RowT = TypeVar("RowT")
+
+
+def query_for_ids(
+    query: QuerySet[ModelT, RowT],
+    user_ids: list[int],
+    field: str,
+) -> QuerySet[ModelT, RowT]:
+    """
+    This function optimizes searches of the form
+    `user_profile_id in (1, 2, 3, 4)` by quickly
+    building the where clauses.  Profiling shows significant
+    speedups over the normal Django-based approach.
+
+    Use this very carefully!  Also, the caller should
+    guard against empty lists of user_ids.
+    """
+    assert user_ids
+    clause = f"{field} IN %s"
+    query = query.extra(  # noqa: S610
+        where=[clause],
+        params=(tuple(user_ids),),
+    )
+    return query