Batch inbox alias resolution to prevent database lock exhaustion

src/msgd/store.py

@@ -4425,23 +4425,26 @@ def _reindex_inbox(self, post_id: int) -> None:
                     events.add((target, "reply"))
 
         text = post.title + "\n" + post.body
+        alias_keys: set[str] = set()
         for token in set(MENTION_RE.findall(text)):
             lowered = token.lower()
-            targets: set[str] = set()
             if AUTHOR_ID_RE.fullmatch(lowered):
-                targets.add(lowered)
+                if lowered != actor_id:
+                    events.add((lowered, "mention"))
             else:
-                rows = self._conn.execute(
-                    """
-                    SELECT author_id
-                      FROM name_claims
-                     WHERE name_key = ?
-                    """,
-                    (self.normalize_identity_name(token),),
-                ).fetchall()
-                targets.update(str(item["author_id"]) for item in rows)
+                alias_keys.add(self.normalize_identity_name(token))
 
-            for target in targets:
+        if alias_keys:
+            rows = self._conn.execute(
+                """
+                SELECT author_id
+                  FROM name_claims
+                 WHERE name_key IN (SELECT value FROM json_each(?))
+                """,
+                (json.dumps(sorted(alias_keys), separators=(",", ":")),),
+            ).fetchall()
+            for item in rows:
+                target = str(item["author_id"])
                 if target != actor_id:
                     events.add((target, "mention"))
 

tests/test_msgd.py

@@ -1874,6 +1874,33 @@ def test_private_inbox_collects_replies_and_mentions(self) -> None:
         self.assertIn(f"[mention] #{direct_id}", inbox)
         self.assertIn("latest_id=", inbox)
 
+    def test_alias_mentions_are_resolved_in_one_query(self) -> None:
+        alice = Ed25519PrivateKey.generate()
+        self.issue_member(alice)
+        self.signed_create(alice, "hello", name="Alice")
+
+        statements: list[str] = []
+        self.server.board.store._conn.set_trace_callback(statements.append)
+        try:
+            status, body = self.c.post(
+                "/publish",
+                board="main",
+                text="ping @Alice " + " ".join(f"@missing{index}" for index in range(1_000)),
+            )
+        finally:
+            self.server.board.store._conn.set_trace_callback(None)
+
+        self.assertEqual(status, 201, body)
+        alias_queries = [
+            statement
+            for statement in statements
+            if "FROM name_claims" in statement and "json_each" in statement
+        ]
+        self.assertEqual(len(alias_queries), 1)
+        status, inbox, _ = self.read_inbox(alice)
+        self.assertEqual(status, 200, inbox)
+        self.assertIn("[mention]", inbox)
+
     def test_inbox_signature_nonce_and_cursor_are_enforced(self) -> None:
         alice = Ed25519PrivateKey.generate()
         mallory = Ed25519PrivateKey.generate()