feat: parallelize asset packing

api/agent-notes/core/app_assets/packager/zip_packager.py.md

@@ -0,0 +1,14 @@
+# Zip Packager Notes
+
+## Purpose
+- Builds a ZIP archive of asset contents stored via the configured storage backend.
+
+## Key Decisions
+- Packaging writes assets into an in-memory zip buffer returned as bytes.
+- Asset fetch + zip writing are executed via a thread pool with a lock guarding `ZipFile` writes.
+
+## Edge Cases
+- ZIP writes are serialized by the lock; storage reads still run in parallel.
+
+## Tests/Verification
+- None yet.

api/core/app_assets/packager/zip_packager.py

@@ -1,5 +1,7 @@
 import io
 import zipfile
+from concurrent.futures import Future, ThreadPoolExecutor
+from threading import Lock
 from typing import TYPE_CHECKING
 
 from core.app_assets.entities import AssetItem
@@ -20,8 +22,21 @@ class ZipPackager(AssetPackager):
         zip_buffer = io.BytesIO()
 
         with zipfile.ZipFile(zip_buffer, "w", zipfile.ZIP_DEFLATED) as zf:
-            for asset in assets:
-                content = self._storage.load_once(asset.get_storage_key())
-                zf.writestr(asset.path, content)
+            lock = Lock()
+            # FOR DELVELPMENT AND TESTING ONLY, TODO: optimize
+            with ThreadPoolExecutor(max_workers=8) as executor:
+                futures: list[Future[None]] = []
+                for asset in assets:
+
+                    def _write_asset(a: AssetItem) -> None:
+                        content = self._storage.load_once(a.get_storage_key())
+                        with lock:
+                            zf.writestr(a.path, content)
+
+                    futures.append(executor.submit(_write_asset, asset))
+
+                # Wait for all futures to complete
+                for future in futures:
+                    future.result()
 
         return zip_buffer.getvalue()