Don't refetch thread for backfilling unless necessary

mauigpapi/http/thread.py

@@ -96,9 +96,19 @@ class ThreadAPI(BaseAndroidAPI):
         )
 
     async def iter_thread(
-        self, thread_id: str, seq_id: int | None = None, cursor: str | None = None
+        self,
+        thread_id: str,
+        seq_id: int | None = None,
+        cursor: str | None = None,
+        start_at: Thread | None = None,
     ) -> AsyncIterable[ThreadItem]:
-        has_more = True
+        if start_at:
+            for item in start_at.items:
+                yield item
+            cursor = start_at.oldest_cursor
+            has_more = start_at.has_older
+        else:
+            has_more = True
         while has_more:
             resp = await self.get_thread(thread_id, seq_id=seq_id, cursor=cursor)
             cursor = resp.thread.oldest_cursor

mautrix_instagram/portal.py

@@ -1451,7 +1451,7 @@ class Portal(DBPortal, BasePortal):
     # endregion
     # region Backfilling
 
-    async def backfill(self, source: u.User, is_initial: bool = False) -> None:
+    async def backfill(self, source: u.User, thread: Thread, is_initial: bool = False) -> None:
         limit = (
             self.config["bridge.backfill.initial_limit"]
             if is_initial
@@ -1462,12 +1462,14 @@ class Portal(DBPortal, BasePortal):
         elif limit < 0:
             limit = None
         with self.backfill_lock:
-            await self._backfill(source, is_initial, limit)
+            await self._backfill(source, thread, is_initial, limit)
 
-    async def _backfill(self, source: u.User, is_initial: bool, limit: int) -> None:
+    async def _backfill(
+        self, source: u.User, thread: Thread, is_initial: bool, limit: int
+    ) -> None:
         self.log.debug("Backfilling history through %s", source.mxid)
 
-        entries = await self._fetch_backfill_items(source, is_initial, limit)
+        entries = await self._fetch_backfill_items(source, thread, is_initial, limit)
         if not entries:
             self.log.debug("Didn't get any items to backfill from server")
             return
@@ -1486,11 +1488,11 @@ class Portal(DBPortal, BasePortal):
         self.log.info("Backfilled %d messages through %s", len(entries), source.mxid)
 
     async def _fetch_backfill_items(
-        self, source: u.User, is_initial: bool, limit: int
+        self, source: u.User, thread: Thread, is_initial: bool, limit: int
     ) -> list[ThreadItem]:
         items = []
         self.log.debug("Fetching up to %d messages through %s", limit, source.igpk)
-        async for item in source.client.iter_thread(self.thread_id):
+        async for item in source.client.iter_thread(self.thread_id, start_at=thread):
             if len(items) >= limit:
                 self.log.debug(f"Fetched {len(items)} messages (the limit)")
                 break
@@ -1597,7 +1599,7 @@ class Portal(DBPortal, BasePortal):
                     f"Last permanent item ({info.last_permanent_item.item_id})"
                     " not found in database, starting backfilling"
                 )
-                await self.backfill(source, is_initial=False)
+                await self.backfill(source, thread=info, is_initial=False)
         await self._update_read_receipts(info.last_seen_at)
 
     async def _create_matrix_room(self, source: u.User, info: Thread) -> RoomID | None:
@@ -1677,7 +1679,7 @@ class Portal(DBPortal, BasePortal):
             await self._update_participants(info.users, source)
 
             try:
-                await self.backfill(source, is_initial=True)
+                await self.backfill(source, thread=info, is_initial=True)
             except Exception:
                 self.log.exception("Failed to backfill new portal")
             await self._update_read_receipts(info.last_seen_at)