Problem:
- HashSet doesn't maintain insertion order
- iter().next() returns arbitrary element, not the oldest
- Cache eviction was unpredictable
Solution:
- Use VecDeque for FIFO ordering
- push_back() adds new block
- pop_front() removes oldest block when cache exceeds 10 elements
- contains() is O(n) but performant for 10 elements
Changes:
- RadioParadiseStreamSourceLogic: recent_blocks now VecDeque<EventId>
- mark_block_downloaded(): simplified with guaranteed FIFO eviction
- Documentation updated with VecDeque usage and advantages
- Add comprehensive technical documentation (RADIO_PARADISE_STREAM_SOURCE.md)
- Add practical usage example (examples/radio_paradise_stream.rs)
- Document architecture, timing algorithm, and API
- Include both basic and advanced usage patterns with nowplaying stream
Implement a new pmoaudio source node that streams Radio Paradise blocks
with automatic TrackBoundary insertion at the correct timing.
Features:
- Downloads and decodes FLAC blocks from Radio Paradise API
- Queue management for block IDs via push_block_id()
- Recent blocks cache (10 blocks) to avoid re-downloads
- Automatic TrackBoundary insertion based on sample count timing
- Converts Song metadata to TrackMetadata with cover URLs
- Timeout of 3 seconds for new block IDs (radio real-time)
- Support for 16-bit and 24-bit FLAC audio
Architecture:
- RadioParadiseStreamSourceLogic: Pure business logic implementing NodeLogic
- RadioParadiseStreamSource: Wrapper using Node<> pattern
- Uses logic_mut() for push_block_id() configuration
The node emits:
- TopZeroSync at block start
- TrackBoundary before each song (with same order as next chunk)
- Audio chunks (I16 or I24)
- EndOfStream on timeout or completion
New pmoaudio feature gate with dependencies on:
- pmoaudio, pmoflac, pmometadata, futures-util
