forked from unom/punktfunk
enricobuehlerandClaude Fable 5
a2433d77cf
Reversed/reordered delivery lets a FEC block reconstruct EARLY (data + recovery >= k), counting still-in-flight shards into fec_recovered_shards; window_loss_ppm then reported pure reordering as loss, inflating LossReports — which size adaptive FEC and, since the Automatic overhaul, feed the ABR controller (one severe window ends slow start FOR GOOD, so a reorder burst could permanently kneecap a session's climb). Early reconstruct stays (it's the latency-right choice); the accounting now nets it out. The reassembler counts a new fec_late_shards stat when a parity-restored data shard ARRIVES after all — matched exactly: the completed/abandoned-frame memory (ReassemblyWindow::completed, now a map) remembers which shards each terminal frame reconstructed, and a late arrival must match one (removed on hit), so wire duplicates of delivered shards and stragglers of failed blocks count nothing. In-flight blocks dedup via have_data. window_loss_ppm takes the late delta and estimates from (recovered - late), saturating across window boundaries; both callers (client core + probe) pass it. The e2e reorder tests now assert the NET equals the true kill count in both delivery orders, dup included (previously documented as a known inflation). Not mirrored into the C-ABI PunktfunkStats — the loss windows run in-core on every platform. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>