fix(cli): apply index updates in place instead of fetching the whole index

The interactive mode fetched and re-parsed the full index on every
index_delta, on the loop receiving the download: 67 times in 80 s while
a node enriched a library.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 21 insertions, 1 deletions

diff --git a/packages/meshbay-cli/tests/fake_node.py b/packages/meshbay-cli/tests/fake_node.py
index c618ee4..47f82b3 100644
--- a/packages/meshbay-cli/tests/fake_node.py
+++ b/packages/meshbay-cli/tests/fake_node.py
@@ -79,6 +79,8 @@ class FakeNode:
         self.members: dict[str, Identity] = {}   # sender → the device it signs with
         self.unresponsive = False            # pings go unanswered, as a dead link's
         self.admin_ops: dict[str, dict] = {}
+        self.channels: list[FakeChannel] = []
+        self.index_syncs = 0                 # full indexes asked for
 
     def add(self, path: str, name: str, data: bytes, uploader_id: str = "") -> dict:
         fid = hashlib.blake2b(data + path.encode() + name.encode(), digest_size=32).hexdigest()
@@ -92,9 +94,26 @@ class FakeNode:
         return entry
 
     def session(self) -> GroupSession:
-        return GroupSession(None, FakeChannel(self), GROUP_ID, "node-1", NODE_PK, self.gek,
+        ch = FakeChannel(self)
+        self.channels.append(ch)
+        return GroupSession(None, ch, GROUP_ID, "node-1", NODE_PK, self.gek,
                             dict(self.ack), self.identity, self.nonce, self.role)
 
+    def push_delta(self, *, additions=(), updates=(), deletions=()) -> None:
+        """An `index_delta` to every session, sealed as the node seals one. The
+        entries are applied here first, so a later `index_sync` agrees."""
+        for e in (*additions, *updates):
+            self.files[e["id"]] = e
+        for fid in deletions:
+            self.files.pop(fid, None)
+        wire = lambda es: [{k: v for k, v in e.items() if k != "data"} for e in es]  # noqa: E731
+        payload = {"base_version": 1, "version": 1, "additions": wire(additions),
+                   "deletions": list(deletions), "updates": wire(updates)}
+        msg = {"type": "index_delta", "group_id": GROUP_ID,
+               **seal(self.gek, PURPOSE_INDEX, "index_delta", GROUP_ID, payload)}
+        for ch in self.channels:
+            ch._emit(msg)
+
     def list_device(self, sender: str, device: Identity, *,
                     countersigned_by: Identity | None = None, proof: bool = True) -> None:
         """A roster row for `sender`'s device: a root, or countersigned by another
@@ -189,6 +208,7 @@ class FakeChannel:
 
     def _index_sync(self, msg):
         n = self.node
+        n.index_syncs += 1
         payload = {"version": 1, "roots": n.roots, "dirs": sorted(n.dirs),
                    "entries": [{k: v for k, v in e.items() if k != "data"}
                                for e in n.files.values()]}