fix(worker): cancel abandoned slskd transfers + cap download fall-through

Two compounding causes of 'many downloads of one album from different sources' in slskd: (1) the slskd client raised on timeout/error WITHOUT cancelling the transfer it enqueued, so as the pipeline fell through to other peers each left a transfer running; (2) the incomplete-download fall-through was uncapped, grinding through every candidate of a popular album (~200 Soulseek peers), amplified now that Qobuz pacing pushes most jobs to Soulseek. - SlskdClient.download now cancels its enqueued transfers (DELETE) on any abandon. - The download loop caps at _MAX_DOWNLOAD_ATTEMPTS (6) candidates. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-15 19:03:05 +02:00
parent 67f374c470
commit 1fc61a0f5a
4 changed files with 140 additions and 0 deletions
@@ -0,0 +1,72 @@
+"""When an slskd download is abandoned (times out or errors), the enqueued transfers must be
+cancelled — otherwise, as the pipeline falls through to other peers for the same album, abandoned
+transfers pile up in slskd (many downloads of one album from different sources)."""
+import json
+
+import pytest
+
+import lyra_worker.adapters._slskd as slskd_mod
+from lyra_worker.adapters._slskd import SlskdClient
+
+
+class _Resp:
+    def __init__(self, payload=None):
+        self._p = payload if payload is not None else {}
+
+    def raise_for_status(self):
+        pass
+
+    def json(self):
+        return self._p
+
+
+class _FakeRequests:
+    """Enqueue OK; polling always reports the file still in progress (never completes); records
+    DELETEs so the test can assert the abandoned transfer was cancelled."""
+    def __init__(self, state="InProgress"):
+        self.deleted = []
+        self._poll = {"directories": [{"files": [
+            {"filename": "f1.flac", "size": 5, "state": state, "id": "t1"},
+        ]}]}
+
+    def post(self, url, **kw):
+        return _Resp({})
+
+    def get(self, url, **kw):
+        return _Resp(self._poll)
+
+    def delete(self, url, **kw):
+        self.deleted.append(url)
+        return _Resp({})
+
+
+def _client(tmp_path):
+    return SlskdClient({"slskd.url": "http://x", "slskd.api_key": "k",
+                        "slskd.downloadsDir": str(tmp_path)})
+
+
+_REF = json.dumps({"username": "peerA", "files": [{"filename": "f1.flac", "size": 5}]})
+
+
+def test_cancels_transfer_on_timeout(tmp_path, monkeypatch):
+    fake = _FakeRequests(state="InProgress")
+    monkeypatch.setattr(slskd_mod, "requests", fake)
+    monkeypatch.setattr(slskd_mod.time, "sleep", lambda _s: None)
+    monkeypatch.setattr(slskd_mod, "_XFER_POLLS", 2)
+
+    with pytest.raises(TimeoutError):
+        _client(tmp_path).download(_REF, str(tmp_path / "dest"), lambda _p: None)
+
+    assert any(u.endswith("/api/v0/transfers/downloads/peerA/t1") for u in fake.deleted), fake.deleted
+
+
+def test_cancels_transfer_on_error_state(tmp_path, monkeypatch):
+    fake = _FakeRequests(state="Completed, Errored")
+    monkeypatch.setattr(slskd_mod, "requests", fake)
+    monkeypatch.setattr(slskd_mod.time, "sleep", lambda _s: None)
+    monkeypatch.setattr(slskd_mod, "_XFER_POLLS", 5)
+
+    with pytest.raises(RuntimeError):
+        _client(tmp_path).download(_REF, str(tmp_path / "dest"), lambda _p: None)
+
+    assert any(u.endswith("/peerA/t1") for u in fake.deleted), fake.deleted