* feat: make NowPlaying dispatch asynchronous with worker pool
Implemented asynchronous NowPlaying dispatch using a queue worker pattern similar to cacheWarmer. Instead of dispatching NowPlaying updates synchronously during the HTTP request, they are now queued and processed by background workers at controlled intervals.
Key changes:
- Added nowPlayingEntry struct to represent queued entries
- Added npQueue map (keyed by playerId), npMu mutex, and npSignal channel to playTracker
- Implemented enqueueNowPlaying() to add entries to the queue
- Implemented nowPlayingWorker() that polls every 100ms, drains queue, and processes entries
- Changed NowPlaying() to queue dispatch instead of calling synchronously
- Renamed dispatchNowPlaying() to dispatchNowPlayingAsync() and updated it to use background context
Benefits:
- HTTP handlers return immediately without waiting for scrobbler responses
- Deduplication by key: rapid calls (seeking) only dispatch latest state
- Fire-and-forget: one-shot attempts with logged failures
- Backpressure-free: worker processes at its own pace
- Tests updated to use Eventually() assertions for async dispatch
Signed-off-by: Deluan <deluan@navidrome.org>
* fix(play_tracker): increase timeout duration for signal handling
Signed-off-by: Deluan <deluan@navidrome.org>
* refactor(play_tracker): simplify queue processing by directly assigning entries
Signed-off-by: Deluan <deluan@navidrome.org>
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Signed-off-by: Deluan <deluan@navidrome.org>