C3+C4 — HTTP/3 frame reader + WebTransport response :status check
New Http3FrameReader buffers stream bytes and yields complete frames
(DATA, HEADERS, SETTINGS, GOAWAY, Unknown). QuicWebTransportFactory
drains the request stream after sending the Extended CONNECT request,
feeds bytes through the reader, decodes the first HEADERS frame via
QPACK, and pulls `:status`. Non-2xx → ConnectRejected. Without this,
any 401/404/500 yielded a "connected" session that silently dropped.
Tests: 5 new H3FrameReader tests covering SETTINGS, HEADERS round-trip,
cross-push reassembly, unknown-type passthrough, multi-frame in one push.
C9 — flow-control enforcement + receive-side crediting
- Send: per-stream `sendCredit` is now consulted before each takeChunk;
bytes beyond `sendCredit - sentOffset` are held back. SendBuffer
exposes `sentOffset` for the writer.
- Receive: appendFlowControlUpdates() emits MAX_STREAM_DATA when the
receive cursor crosses half the advertised window, and MAX_DATA at
the connection level. Without this, peer windows close and any
sustained transfer wedges silently.
Tier-2 cleanups (six items in one batch):
- AckTracker.purgeBelow(): drop ranges below peer's largest_acked when
we receive an ACK frame. Range list no longer grows unboundedly on
long connections.
- ReceiveBuffer adjacency edge: pull in the prior chunk when its
endOffset exactly equals the new chunk's start. Previously perfectly-
sequential receives starting at offset > 0 left adjacent chunks
unmerged, growing the chunk list and overcounting bufferedAhead.
- RetryPacket integrity-tag verify: constant-time compare instead of
contentEquals.
- ServerHello legacy_session_id_echo MUST be empty per RFC 8446 §4.1.3
(we send empty); reject non-empty as a downgrade signal.
- TLS state machine handles post-handshake NewSessionTicket and
KeyUpdate at Application level — silently drop instead of throwing
"unexpected post-handshake type" and tearing down the connection.
Tier-3 perf: SendBuffer chunked queue
Replaced the O(N) copyOf-on-every-enqueue with an ArrayDeque<ByteArray>
+ headOffset cursor. Enqueue is now O(1); takeChunk peels at most one
head chunk. Memory is bounded by the sum of outstanding writes instead
of (sum)². For sustained MoQ stream writes of small chunks this drops
from O(N²) memcpy to O(N).
All :quic:jvmTest + :nestsClient:jvmTest pass — every RFC 9001 Appendix A
vector still verifies bit-for-bit.
Remaining items deferred:
Tier-2: incremental transcript hash (low impact: 4-5 calls per handshake
over <10 KB), TLS HelloRetryRequest detection (we never send
incompatible ClientHello today, server won't HRR).
Tier-3: cipher reuse, Huffman lookup tree, UdpSocket selector, packet
codec triple-allocation. None block live interop; revisit if
measured RTT or CPU surfaces them.
https://claude.ai/code/session_01EC1tfXfap8k8GyKvrxkxZx
Claude
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