QuicConnectionParser's AckFrame handler now drains
state.sentPackets of every entry whose packet number is covered by
the ACK's ranges. The drained SentPackets are returned but
discarded for now; step 5 will route them to loss detection / RTT.
New helper file `connection/recovery/AckedPackets.kt`:
- forEachAckedPacketNumber(ack, block): inline iterator over an
AckFrame's ranges in RFC 9000 §19.3.1 order. Walks first range
[largestAcked - firstAckRange, largestAcked] then each
additional range with `nextLargest = previousSmallest - gap - 2`,
`nextSmallest = nextLargest - ackRangeLength`. Defensive clamp
at PN 0 against malformed peer ACKs.
- drainAckedSentPackets(sentPackets, ack): walks via
forEachAckedPacketNumber and removes each matching entry from
the map. Returns the drained list.
Wired into QuicConnectionParser.kt:165 alongside the existing
ackTracker.purgeBelow call.
Tests added (9, all pass):
- simpleRange / multipleRanges / singlePacketAck: range walking
for typical ACK shapes
- ackForUnsentPn_isNoOp / emptyMap_returnsEmptyDrain: defensive
paths
- ackBoundary_pn0Inclusive: PN 0 is correctly included, no
underflow
- forEachAckedPacketNumber_iteratesDescending /
forEachAckedPacketNumber_acrossMultipleRanges_descending:
iterator semantics
- returnedDrain_preservesTokens: drained SentPacket retains its
full tokens list — step 5+ will dispatch these to RTT / loss
Mirror of neqo's `recovery/mod.rs::remove_acked` (one of the 20
recovery tests we owe per
`quic/plans/2026-05-04-control-frame-retransmit.md`). The remaining
loss-detection tests land in step 5.
Full :quic test suite + nestsClient moq-lite tests pass.
https://claude.ai/code/session_01PYYez8a6sjiakyjAxsfCEQ
Claude
0ced269b27