hpack encoder optimizations.
Removed some cycles and branches from hpack_enc for CH2.
Specifically:
1. Pushed certain metadata key/value length checks to
prepare_application_metadata() in src/core/lib/surface/call.cc.
This means that rather than check all key/val lengths for all metadata, we only
do so for custom added user metadata. Inside CH2, we change the length checks to
debug checks so we can catch if core/filter metadata fails to pass the check.
2. Changed various asserts to debug asserts when able.
3. Refactored some of the header emission code to remove duplicated code.
4. Un-inlined some logging methods.
This results in somewhat faster hpack_encoder performance:
BM_HpackEncoderInitDestroy
222ns ± 0% 221ns ± 0% -0.29% (p=0.000 n=34+34)
BM_HpackEncoderEncodeDeadline
[framing_bytes/iter:9 header_bytes/iter:6 ] 135ns ± 1%
124ns ± 0% -8.05% (p=0.000 n=39+38)
BM_HpackEncoderEncodeHeader<EmptyBatch>/0/16384
[framing_bytes/iter:9 header_bytes/iter:0 ] 34.2ns ± 0%
34.2ns ± 0% -0.01% (p=0.014 n=34+38)
BM_HpackEncoderEncodeHeader<EmptyBatch>/1/16384
[framing_bytes/iter:9 header_bytes/iter:0 ] 34.2ns ± 0%
34.2ns ± 0% -0.04% (p=0.004 n=34+37)
BM_HpackEncoderEncodeHeader<SingleStaticElem>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.5ns ± 0%
45.9ns ± 0% -3.28% (p=0.000 n=28+38)
BM_HpackEncoderEncodeHeader<SingleInternedKeyElem>/0/16384
[framing_bytes/iter:9 header_bytes/iter:6 ] 77.0ns ± 1%
68.3ns ± 1% -11.33% (p=0.000 n=39+40)
BM_HpackEncoderEncodeHeader<SingleInternedElem>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.7ns ± 1%
45.5ns ± 0% -4.63% (p=0.000 n=39+33)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<1, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.2ns ± 0%
45.3ns ± 0% -3.96% (p=0.000 n=33+34)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<3, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.7ns ± 0%
45.6ns ± 0% -4.54% (p=0.000 n=38+40)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<10, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.7ns ± 0%
45.5ns ± 0% -4.63% (p=0.000 n=39+32)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<31, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.8ns ± 0%
45.6ns ± 1% -4.59% (p=0.000 n=38+39)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<100, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.8ns ± 0%
45.5ns ± 0% -4.64% (p=0.000 n=39+36)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<1, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.3ns ± 0%
45.3ns ± 0% -4.09% (p=0.000 n=38+36)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<3, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.8ns ± 1%
45.6ns ± 0% -4.71% (p=0.000 n=37+40)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<10, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.7ns ± 0%
45.5ns ± 0% -4.66% (p=0.000 n=39+32)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<31, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.8ns ± 1%
45.6ns ± 1% -4.62% (p=0.000 n=37+39)
BM_HpackEncoderEncodeHeader<SingleInternedBinaryElem<100, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.7ns ± 0%
45.5ns ± 0% -4.67% (p=0.000 n=38+32)
BM_HpackEncoderEncodeHeader<SingleNonInternedElem>/0/16384
[framing_bytes/iter:9 header_bytes/iter:9 ] 80.5ns ± 1%
74.7ns ± 0% -7.16% (p=0.000 n=38+35)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<1, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:12 ] 105ns ± 1%
99ns ± 0% -5.91% (p=0.000 n=38+34)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<3, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:14 ] 111ns ± 1%
106ns ± 1% -4.86% (p=0.020 n=39+2)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<10, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:23 ] 135ns ± 0%
130ns ± 0% -3.45% (p=0.020 n=35+2)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<31, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:46 ] 225ns ± 1%
223ns ± 0% -0.91% (p=0.003 n=37+2)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<100, false>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:120 ] 467ns ± 0%
472ns ± 0% +1.09% (p=0.003 n=38+2)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<1, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:12 ] 81.6ns ± 1%
74.8ns ± 0% -8.40% (p=0.000 n=37+33)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<3, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:14 ] 82.0ns ± 1%
74.8ns ± 0% -8.80% (p=0.000 n=37+32)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<10, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:21 ] 82.1ns ± 1%
74.9ns ± 0% -8.86% (p=0.000 n=35+34)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<31, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:42 ] 97.6ns ± 2%
91.8ns ± 0% -5.95% (p=0.000 n=35+27)
BM_HpackEncoderEncodeHeader<SingleNonInternedBinaryElem<100, true>>/0/16384
[framing_bytes/iter:9 header_bytes/iter:111 ] 97.2ns ± 1%
91.2ns ± 2% -6.19% (p=0.000 n=37+38)
BM_HpackEncoderEncodeHeader<SingleNonInternedElem>/0/1
[framing_bytes/iter:54 header_bytes/iter:9 ] 230ns ± 0%
221ns ± 0% -3.91% (p=0.000 n=38+37)
BM_HpackEncoderEncodeHeader<MoreRepresentativeClientInitialMetadata>/0/16384
[framing_bytes/iter:9 header_bytes/iter:16 ] 206ns ± 2%
170ns ± 1% -17.51% (p=0.000 n=39+39)
BM_HpackEncoderEncodeHeader<RepresentativeServerInitialMetadata>/0/16384
[framing_bytes/iter:9 header_bytes/iter:3 ] 66.4ns ± 2%
62.5ns ± 1% -5.85% (p=0.000 n=34+39)
BM_HpackEncoderEncodeHeader<RepresentativeServerTrailingMetadata>/1/16384
[framing_bytes/iter:9 header_bytes/iter:1 ] 47.5ns ± 0%
45.9ns ± 1% -3.29% (p=0.000 n=26+38)
Arjun Roy