Use HPACK spelling for HTTP/2 compression - #2271
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When compression is enforced, the request factory creates the default Accept-Encoding value as "gzip,deflate" for HTTP/1 compatibility. HTTP/2's HPACK static table contains "gzip, deflate", so the H2 frame writer missed the compact static entry for the generated default. Rewrite only the generated default while copying headers into HTTP/2 frames. User-supplied Accept-Encoding values keep their original spelling, and HTTP/1 output remains unchanged. Codex on behalf of Pavel Ptashyts Co-Authored-By: Codex <codex@openai.com>
Add a deterministic encoder test proving that the HPACK static-table spelling uses a one-byte indexed representation while the old spelling requires a literal value. Clarify that the JMH benchmark reports execution time and allocation; its return value prevents dead-code elimination but is not a separate JMH metric. Codex on behalf of Pavel Ptashyts Co-Authored-By: Codex <codex@openai.com>
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July 20, 2026 15:08
Replace the remaining non-ASCII punctuation in the touched HPACK benchmark so the source follows the repository guidelines in AGENTS.md. Codex on behalf of Pavel Ptashyts Co-Authored-By: Codex <codex@openai.com>
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July 20, 2026 15:45
hyperxpro
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Jul 24, 2026
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client/src/main/java/org/asynchttpclient/netty/request/NettyRequestSender.java
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client/src/main/java/org/asynchttpclient/netty/request/NettyRequestSender.java
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client/src/main/java/org/asynchttpclient/netty/request/NettyRequestSender.java
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client/src/test/java/org/asynchttpclient/BasicHttp2Test.java
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client/src/test/java/org/asynchttpclient/BasicHttp2Test.java
Use the interned generated Accept-Encoding value as the marker for the HTTP/2 HPACK rewrite, avoiding request lookups during frame conversion. Keep the HPACK spelling beside the shared HTTP/1 value and verify the generated values across HTTP/1, HTTP/2, and optional codecs. Codex on behalf of Pavel Ptashyts Co-Authored-By: Codex <codex@openai.com>
hyperxpro
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Jul 25, 2026
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Summary
Performance evidence
With Netty 4.2.15.Final and a fresh HPACK encoder:
A short JMH validation on JDK 21 with -prof gc measured 1032 B/op for the literal spelling and 680 B/op for the static-table spelling. Timing was noisy, so this PR relies on the deterministic wire-size test rather than claiming a stable CPU improvement.
Validation
Attribution
Codex on behalf of Pavel Ptashyts