Files
Flash5/flash/docs/http2
Zakaria El Orche a0dda8e47a refactor(core): remove out-of-scope HTTP/2 client/proxy, reorganize docs, refresh README
HttpProxy and Http2Client (719 LOC) shipped a reverse-proxy adapter and outbound HTTP/2
client from flash core with zero callers anywhere in the server itself — only each
other and their own tests. An HTTP/1.1+2 server framework has no business bundling an
outbound client; that capability belongs in its own flash-extensions/flash-ext-*
module if/when it's needed. Removed, along with the now-dead src/bench load driver
that depended on Http2Client (no replacement client written here — flagged as
follow-up work, not silently dropped).

docs/http2/ had accumulated core, cross-protocol documentation alongside genuine
HTTP/2-protocol internals: HTTP1-HARDENING, TRANSPORT, MESSAGE-MODEL,
TRAILERS-AND-STREAMING and BYTES all describe machinery HTTP/1.1 and HTTP/2 share, not
HTTP/2 specifically. Moved to a new docs/core/, leaving docs/http2/ to the protocol
layers, wire internals and operational docs that are actually HTTP/2-specific.
CLEARTEXT-AND-PROXY.md renamed to CLEARTEXT.md and its now-removed upstream-client
section cut, matching the source removal above.

README.md: removed the "HTTP/2 upstream proxy" section (documented the deleted
HttpProxy/Http2Client), the flash-bench module row and build command (not a module
that exists in this repo), and fixed every doc link to the new docs/core/ paths.
Added the new FlashConfiguration.maxConnections field to the configuration reference.

src/bench/ (a load-test harness distinct from the JMH suite, not wired into any Maven
profile or CI) is committed here for the first time.
2026-08-14 18:13:03 +00:00
..
2026-08-13 18:04:22 +00:00

HTTP/2 in Flash

Flash treats HTTP/1.1 and HTTP/2 as peer transports behind one connection boundary. TLS ALPN or the cleartext prior-knowledge preface selects a protocol once; both paths then feed the same router, Request, Response, handler, trailer, streaming and WebSocket APIs. HTTP/2 adds a bounded frame decoder, HPACK codec, stream state machine, two-level flow control and one serialized writer per connection. Application code does not branch on the wire protocol.

The implementation is deliberately layered:

listener / TLS
    -> protocol negotiation
        -> HTTP/1.1 parser ---------+
        -> HTTP/2 frames + HPACK ----+-> shared request model -> router -> handler
                                         shared response model
        <- HTTP/1.1 serializer -----+
        <- HTTP/2 stream writer ----+

This page covers the HTTP/2-specific layers only. The transport, message model, and byte primitives shared with HTTP/1.1 live in ../core/.

Protocol layers

  • Connection and streams — HTTP/2 connection and stream state.
  • Flow control — request backpressure and streamed responses.
  • Cleartext — prior knowledge and the 421 misdirected-request rule.
  • WebSockets — RFC 8441 extended CONNECT using the existing WebSocket API.

Wire internals

  • Serialized writer — the single-owner output path and contention model.
  • Frames — frame parsing, validation and error scope.
  • HPACK — integer/Huffman coding and static/dynamic table ownership.

Operate and verify

  • Security — every HTTP/2 limit, default and abuse control.
  • Troubleshooting — GOAWAY/RST_STREAM diagnosis and protocol tracing.
  • Compliance — h2spec, interoperability, fuzzing and deliberate omissions.
  • Performance and CI baselines — measurements and regression gates, including the comparison with nghttpd.