Pinning gaps he flagged after his second pass:
- register_plugin when set_engine() raises: registration must succeed
+ plugin stays in the registry (download() raises later, surfacing
the error to the user via download_with_fallback). Pin so a future
refactor can't accidentally propagate the set_engine exception and
crash boot.
- engine.get_all_downloads exclude actually doesn't invoke the plugin:
ID-only check would pass even if soulseek's get_all was called and
returned []; sentinel proves the plugin isn't touched at all.
- Cancel mid-flight observable from inside _download_sync: existing
tests pin Cancelled-preserve AFTER impl returns, this pins the
contract plugins rely on (engine.get_record reflecting Cancelled
state during the impl thread's polling loop).
- configured_clients() with broken is_configured(): the try/except
guard exists but had no test — broken plugin is silently skipped,
healthy ones still surface.
- Per-source delay independence: YouTube's 3s rate-limit delay must
not block a Tidal download starting in parallel. Companion to the
per-source-locks test.
Two findings from JohnBaumb on the engine refactor.
(1) Every download client returned None when self._engine was None,
just logging an error. The orchestrator's download_with_fallback
treated None as "source declined", so the user got no feedback —
download silently disappeared. Now each client raises a RuntimeError
on the engine-not-wired path. download_with_fallback already catches
plugin exceptions, logs a warning, and tries the next source — so
the visible behavior is "real error in logs + fallback to next
source" instead of "silent drop". Six clients touched (deezer, hifi,
qobuz, soundcloud, tidal, youtube). Pinning tests updated to expect
raise.
(2) Monitor's engine.get_all_downloads() walked every plugin
including soulseek, but the same monitor loop already pulled slskd
transfers via the transfers/downloads endpoint a few lines earlier —
soulseek's records were being fetched twice per tick. Same issue in
web_server.py's get_cached_transfer_data path. Added an exclude
parameter to engine.get_all_downloads(); both call sites now pass
('soulseek',). New test pins the exclude semantic.
Also fixed a stray 8-space over-indent on the for-loop body in
get_cached_transfer_data (cosmetic, JohnBaumb flagged the same
pattern in monitor.py earlier).
Per JohnBaumb: the single state_lock serialized progress callbacks
across every source. Pre-refactor each client owned its own download
lock, so Deezer / YouTube / Tidal workers never blocked each other.
Multi-source concurrent downloads under the unified lock fought for
the same RLock on every progress update.
Replaced the engine-wide state_lock with per-source RLocks. Each
source gets its own lock, lazily created via _source_lock() on first
use (meta-lock guards the create-race). All record mutations
(add/update/update_unless_state/remove/get/iter) take only that
source's lock — Deezer progress updates no longer block Tidal writes.
Cancelled-preserve semantics still hold because cancel + worker
terminal write target the same source, so they share that source's
lock. New test pins lock independence: holding source-A's lock from
one thread does not block a write on source-B from another.
Per JohnBaumb's review: iter_records_for_source() walked every
(source, id) tuple across the entire engine state to filter one
source — O(total_records) instead of O(source_records). Fine in
practice because total active downloads is usually small, but the
shape was wrong.
Switched the engine's _records storage from a single composite-key
dict (Dict[Tuple[str, str], DownloadRecord]) to a nested dict
(Dict[str, Dict[str, DownloadRecord]]). Per-source iteration now
only touches that source's bucket. add/get/update/remove all
adjusted to the nested layout. remove_record drops the empty source
bucket so future iterations don't see stale source keys.
Public surface unchanged. New test pins the empty-bucket-cleanup
behavior.
Three correctness fixes from kettui's PR review plus the web_server
migration to generic accessors.
- Engine alias map: register_plugin accepts aliases tuple; get_plugin
+ cancel_download resolve through it. Fixes deezer_dl cancels
silently routing to soulseek.
- Orchestrator hybrid_order normalization: _resolve_source_chain
routes raw config names through registry.get_spec() so legacy
deezer_dl entries don't drop deezer from hybrid mode.
- Atomic update_record_unless_state on the engine: holds state_lock
across the check + write. Both _mark_terminal AND the success path
use it now so a Cancelled state set mid-impl can't be clobbered.
- web_server.py: 30 soulseek_client.<source> reaches migrated to
client("<source>"); shutdown-check setup migrated to generic
registry iteration; 4 hifi reload sites use reload_instances('hifi').
- 18 new tests pin every fix.
Three findings from a final review pass:
1. **Worker clobbered Cancelled with Errored when impl returned
None / raised mid-cancel.** The legacy per-client thread workers
each had a guard (``if state != 'Cancelled': state = 'Errored'``);
the shared worker dropped it. Fix: new ``_mark_terminal`` helper
in BackgroundDownloadWorker reads current state before writing
the terminal one and leaves Cancelled alone. SoundCloud test
updated back to the strict Cancelled-only assertion (had been
loosened to accept Errored as a workaround). Two new pinning
tests catch the regression.
2. **Dead code in engine.py.** ``find_record`` and
``iter_all_records`` had no production callers — only tests.
Removed them. Concurrent-add stress test rewritten to use the
per-source iterator that's actually in use.
3. **Silent ``except Exception: pass`` in cross-source query
methods.** Faithful to legacy behavior (one source failing
shouldn't take down aggregation) but Cin's standard is "log
even when you swallow." Each silent-swallow site now logs at
debug level so the source name + exception are inspectable
without adding warning-level noise.
Suite still green (2049 passed).
`engine.search_with_fallback(query, source_chain, ...)` walks the
chain in order, skips unconfigured / unregistered plugins,
swallows per-source exceptions, and returns the first non-empty
(tracks, albums) tuple. Replaces orchestrator's hand-rolled
hybrid search loop.
`engine.download_with_fallback(username, filename, file_size,
source_chain)` falls through the chain when a source returns
None / raises. Username hint promotes a matching source-chain
entry to head of order. NOT yet wired into orchestrator.download
— today's username comes from a search result and represents
the user's explicit source pick, so silently falling through
would override their choice. Engine method is available for
future callers that want fallback semantics
(search_and_download_best, automation).
Orchestrator gains _resolve_source_chain helper that builds
the ordered list (hybrid_order config, falling back to legacy
primary/secondary pair). Orchestrator.search hands chain off
to engine.search_with_fallback for hybrid mode.
8 new tests pin the fallback semantics: chain ordering,
unconfigured-skip, exception-continue, empty-when-exhausted,
username-hint promotion. Suite still green (2050 passed).
`DownloadEngine` grows async query methods that wrap plugin
iteration: `get_all_downloads` (concatenates every plugin's
active downloads), `get_download_status` (first plugin to
recognize the id wins), `cancel_download` (with source-hint
routing — streaming sources go direct, unknown hints route to
Soulseek as peer username), and `clear_all_completed_downloads`
(skips unconfigured plugins).
Code moved from the orchestrator's hand-iterated loops into the
engine. Orchestrator delegation comes in B3 — for B2 the engine
methods exist but nothing calls them yet.
Per-plugin behavior preserved verbatim (defensive `try ... except`
swallows per-iteration, unconfigured-skip on clear, source-hint
routing semantics). Phase A pinning tests + 8 new engine query
tests catch any drift.
Pure additive — zero behavior change for users.
`core/download_engine/` package with the engine class that will own
cross-source state, threading, search retry, rate-limits, and
fallback chains. Orchestrator constructs an engine and registers
each plugin with it.
Phase B1 scope: skeleton only. Engine stores active_downloads
records keyed by (source, download_id), provides thread-safe
add/update/remove/iterate primitives, and holds plugin references
for later phases. NOT on any code path yet — pure additive
scaffolding so subsequent commits can introduce engine-driven
behavior one piece at a time without a big-bang switchover.
15 new tests pin the engine's state-storage contract: shallow-copy
reads, partial-patch updates, no-op-on-missing semantics,
per-source iteration, id-only find, concurrent-add safety.
Suite still 290 (download subset) green. Zero behavior change.
