⚡ Bolt: Make Deezer get_downloadable calls async

.jules/bolt.md

@@ -1,3 +1,7 @@
 ## 2025-03-20 - Database Connection Pooling
 **Learning:** `streamrip/db.py` creates a new `sqlite3.connect` for *every single database operation* (`contains`, `add`, `all`). In bulk operations like resolving a playlist with hundreds of tracks, this introduces significant overhead.
 **Action:** Use a single persistent connection per database instance instead of creating a new one on every method call.
+
+## 2026-03-20 - Non-blocking I/O in Deezer client
+**Learning:** `streamrip/client/deezer.py` uses the synchronous `deezer-python` library. Direct calls like `client.gw.get_track()` and `client.get_track_url()` block the entire `asyncio` event loop. While the metadata fetching methods (`get_track`, `get_album`, etc.) correctly wrapped these calls in `await asyncio.to_thread(...)`, `get_downloadable` missed this, causing heavy blocking during concurrent downloads.
+**Action:** Ensure all synchronous third-party API calls in async methods are wrapped with `await asyncio.to_thread(...)`.

streamrip/client/deezer.py

@@ -148,7 +148,7 @@ async def get_downloadable(
         # TODO: optimize such that all of the ids are requested at once
         dl_info: dict = {"quality": quality, "id": item_id}
 
-        track_info = self.client.gw.get_track(item_id)
+        track_info = await asyncio.to_thread(self.client.gw.get_track, item_id)
 
         fallback_id = track_info.get("FALLBACK", {}).get("SNG_ID")
 
@@ -161,7 +161,7 @@ async def get_downloadable(
             int(track_info.get(f"FILESIZE_{format}", 0)) for _, format in quality_map
         ]
         dl_info["quality_to_size"] = size_map
-        
+
         # Check if requested quality is available
         if size_map[quality] == 0:
             if self.config.lower_quality_if_not_available:
@@ -178,7 +178,7 @@ async def get_downloadable(
                 raise NonStreamableError(
                     f"The requested quality {quality} is not available and fallback is disabled."
                 )
-        
+
         # Update the quality in dl_info to reflect the final quality used
         dl_info["quality"] = quality
 
@@ -187,7 +187,7 @@ async def get_downloadable(
         token = track_info["TRACK_TOKEN"]
         try:
             logger.debug("Fetching deezer url with token %s", token)
-            url = self.client.get_track_url(token, format_str)
+            url = await asyncio.to_thread(self.client.get_track_url, token, format_str)
         except deezer.WrongLicense:
             raise NonStreamableError(
                 "The requested quality is not available with your subscription. "

streamrip/db.py

@@ -82,7 +82,7 @@ def __init__(self, path: str):
 
     def __del__(self):
         """Ensure connection is closed on exit."""
-        if hasattr(self, 'conn') and self.conn:
+        if hasattr(self, "conn") and self.conn:
             self.conn.close()
 
     def _table_exists(self) -> bool:
@@ -168,7 +168,7 @@ def all(self):
 
     def reset(self):
         """Delete the database file."""
-        if hasattr(self, 'conn') and self.conn:
+        if hasattr(self, "conn") and self.conn:
             self.conn.close()
             self.conn = None
         try: