forked from unom/punktfunk
Delivery used to be all-or-nothing: the decoder saw byte 0 only after the last packet of the AU landed, so the whole transmit time sat in front of decode. With the slice-streamed wire (previous commit) blocks now arrive addressable, and a client can opt in (connect's new frame_parts) to receive each AU's newly-contiguous prefix as Frame::part pieces - offset tiling, first/last marked, the completing push carrying only the suffix. A PARTIAL_FRAME-capable decoder then chews slices concurrently with the remaining network transfer. The reassembler walks a per-frame cursor over successfully-completed blocks (failed FEC reconstructs don't advance it), coalesces blocks that finished out of order into one part, keeps probe filler whole, and stops short of the final block so the zero-padded tail still trims at completion. Whole-frame consumers see byte-identical behavior - parts never flow without the opt-in, and never on PyroWave (its newest-wins draining assumes whole AUs). Per-AU accounting keeps its units: OWD/ABR feeds, the inter-arrival series and the clock-based jump-to-live detector only count completing deliveries, and FrameChannel::depth() counts AUs so a part-rich queue can't trip jump-to-live at a fraction of the real backlog. The consumer contract (gap or orphan part = AU lost: abandon, flush, resync on the next first) is documented on FramePart; the C ABI keeps parts off until PunktfunkFrame can express them. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>