Prefetch some notes when following an actor

app/activitypub.py

@@ -166,6 +166,7 @@ async def parse_collection(  # noqa: C901
     url: str | None = None,
     payload: RawObject | None = None,
     level: int = 0,
+    limit: int = 0,
 ) -> list[RawObject]:
     """Resolve/fetch a `Collection`/`OrderedCollection`."""
     if level > 3:
@@ -193,7 +194,9 @@ async def parse_collection(  # noqa: C901
         if "first" in payload:
             if isinstance(payload["first"], str):
                 out.extend(
-                    await parse_collection(url=payload["first"], level=level + 1)
+                    await parse_collection(
+                        url=payload["first"], level=level + 1, limit=limit
+                    )
                 )
             else:
                 if "orderedItems" in payload["first"]:
@@ -202,7 +205,9 @@ async def parse_collection(  # noqa: C901
                     out.extend(payload["first"]["items"])
                 n = payload["first"].get("next")
                 if n:
-                    out.extend(await parse_collection(url=n, level=level + 1))
+                    out.extend(
+                        await parse_collection(url=n, level=level + 1, limit=limit)
+                    )
         return out
 
     while payload:
@@ -212,7 +217,7 @@ async def parse_collection(  # noqa: C901
             if "items" in payload:
                 out.extend(payload["items"])
             n = payload.get("next")
-            if n is None:
+            if n is None or (limit > 0 and len(out) >= limit):
                 break
             payload = await fetch(n)
         else:

app/actor.py

@@ -68,6 +68,10 @@ class Actor:
     def inbox_url(self) -> str:
         return self.ap_actor["inbox"]
 
+    @property
+    def outbox_url(self) -> str:
+        return self.ap_actor["outbox"]
+
     @property
     def shared_inbox_url(self) -> str:
         return self.ap_actor.get("endpoints", {}).get("sharedInbox") or self.inbox_url

app/boxes.py

@@ -132,6 +132,8 @@ async def send_like(db_session: AsyncSession, ap_object_id: str) -> None:
         raw_object = await ap.fetch(ap.get_id(ap_object_id))
         await save_object_to_inbox(db_session, raw_object)
         await db_session.commit()
+        # XXX: we need to reload it as lazy-loading the actor will fail
+        # (asyncio SQLAlchemy issue)
         inbox_object = await get_inbox_object_by_ap_id(db_session, ap_object_id)
         if not inbox_object:
             raise ValueError("Should never happen")
@@ -165,6 +167,8 @@ async def send_announce(db_session: AsyncSession, ap_object_id: str) -> None:
         raw_object = await ap.fetch(ap.get_id(ap_object_id))
         await save_object_to_inbox(db_session, raw_object)
         await db_session.commit()
+        # XXX: we need to reload it as lazy-loading the actor will fail
+        # (asyncio SQLAlchemy issue)
         inbox_object = await get_inbox_object_by_ap_id(db_session, ap_object_id)
         if not inbox_object:
             raise ValueError("Should never happen")
@@ -1615,6 +1619,9 @@ async def save_to_inbox(
                     inbox_object_id=inbox_object.id,
                 )
                 db_session.add(notif)
+                if activity_ro.ap_type == "Accept":
+                    # Pre-fetch the latest activities
+                    await _prefetch_actor_outbox(db_session, actor)
             else:
                 logger.info(
                     "Received an Accept for an unsupported activity: "
@@ -1750,10 +1757,41 @@ async def save_to_inbox(
     await db_session.commit()
 
 
+async def _prefetch_actor_outbox(
+    db_session: AsyncSession,
+    actor: models.Actor,
+) -> None:
+    """Try to fetch some notes to fill the stream"""
+    saved = 0
+    outbox = await ap.parse_collection(actor.outbox_url, limit=20)
+    for activity in outbox:
+        activity_id = ap.get_id(activity)
+        raw_activity = await ap.fetch(activity_id)
+        if ap.as_list(raw_activity["type"])[0] == "Create":
+            obj = await ap.get_object(raw_activity)
+            saved_inbox_object = await get_inbox_object_by_ap_id(
+                db_session, ap.get_id(obj)
+            )
+            if not saved_inbox_object:
+                saved_inbox_object = await save_object_to_inbox(db_session, obj)
+
+            if not saved_inbox_object.in_reply_to:
+                saved_inbox_object.is_hidden_from_stream = False
+                saved += 1
+
+        if saved >= 5:
+            break
+
+    # commit is performed by the called
+
+
 async def save_object_to_inbox(
     db_session: AsyncSession,
     raw_object: ap.RawObject,
 ) -> models.InboxObject:
+    """Used to save unknown object before intetacting with them, i.e. to like
+    an object that was looked up, or prefill the inbox when an actor accepted
+    a follow request."""
     obj_actor = await fetch_actor(db_session, ap.get_actor_id(raw_object))
 
     ro = RemoteObject(raw_object, actor=obj_actor)

tests/utils.py

@@ -7,6 +7,7 @@ import fastapi
 import httpx
 import respx
 
+from app import activitypub as ap
 from app import actor
 from app import httpsig
 from app import models
@@ -45,6 +46,18 @@ def setup_remote_actor(respx_mock: respx.MockRouter) -> actor.RemoteActor:
         username="toto",
         public_key="pk",
     )
+    respx_mock.get(ra.ap_id + "/outbox").mock(
+        return_value=httpx.Response(
+            200,
+            json={
+                "@context": ap.AS_EXTENDED_CTX,
+                "id": f"{ra.ap_id}/outbox",
+                "type": "OrderedCollection",
+                "totalItems": 0,
+                "orderedItems": [],
+            },
+        )
+    )
     respx_mock.get(ra.ap_id).mock(return_value=httpx.Response(200, json=ra.ap_actor))
     return ra