envoyproxy
"Compiled" static header maps instead of big trie
Commit Message: "Compiled" static header maps instead of big trie Additional Description: This is slightly slower for "misses" but significantly faster for "hits". Given that the majority of headers are expected to be matches for the static table, this should be a big win. (Each faster hit pays for 30 slower misses!) This structure also uses significantly less memory than the big trie.
Performance benchmarks - bazel run -c opt test/common/http:header_map_impl_speed_test -- --benchmark_filter="bm*" --benchmark_repetitions=25 --benchmark_display_aggregates_only
| Benchmark | before | after | beforeStdDev | afterStdDev | change |
|---|---|---|---|---|---|
| bmHeaderMapImplRequestStaticLookupHits | 47.2ns | 16.4ns | 0.629 | 0.378 | -65.3% |
| bmHeaderMapImplResponseStaticLookupHits | 34.7ns | 14.3ns | 0.571 | 0.085 | -58.8% |
| bmHeaderMapImplRequestStaticLookupMisses | 6.89ns | 6.83ns | 0.044 | 0.034 | -0.01% |
| bmHeaderMapImplResponseStaticLookupMisses | 6.40ns | 7.31ns | 0.028 | 0.057 | +14.2% |
Risk Level: Could be high since headers are parsed millions of times per second. But also there's a lot of existing test cases. Testing: Added tests, existing tests involving headers will also provide coverage. Docs Changes: n/a Release Notes: Not yet Platform Specific Features: n/a
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:cat:
Caused by: https://github.com/envoyproxy/envoy/pull/33932 was opened by ravenblackx.
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wdyt of adding a diagram showing the algorithm in action, as an md file or image or whatever?
wdyt of adding a diagram showing the algorithm in action, as an md file or image or whatever?
Done.
actually I'd love to take one more quick pass; just been slammed. Give me till EOD today?
I agree this is fantastic.