1 Commits

Author	SHA1	Message	Date
Carl Mastrangelo	ff0045e3e1	Use Table lookup for HPACK decoder (#9307) ... Motivation: Table based decoding is fast. Modification: Use table based decoding in HPACK decoder, inspired by https://github.com/python-hyper/hpack/blob/master/hpack/huffman_table.py This modifies the table to be based on integers, rather than 3-tuples of bytes. This is for two reasons: 1. It's faster 2. Using bytes makes the static intializer too big, and doesn't compile. Result: Faster Huffman decoding. This only seems to help the ascii case, the other decoding is about the same. Benchmarks: ``` Before: Benchmark (limitToAscii) (sensitive) (size) Mode Cnt Score Error Units HpackDecoderBenchmark.decode true true SMALL thrpt 20 426293.636 ± 1444.843 ops/s HpackDecoderBenchmark.decode true true MEDIUM thrpt 20 57843.738 ± 725.704 ops/s HpackDecoderBenchmark.decode true true LARGE thrpt 20 3002.412 ± 16.998 ops/s HpackDecoderBenchmark.decode true false SMALL thrpt 20 412339.400 ± 1128.394 ops/s HpackDecoderBenchmark.decode true false MEDIUM thrpt 20 58226.870 ± 199.591 ops/s HpackDecoderBenchmark.decode true false LARGE thrpt 20 3044.256 ± 10.675 ops/s HpackDecoderBenchmark.decode false true SMALL thrpt 20 2082615.030 ± 5929.726 ops/s HpackDecoderBenchmark.decode false true MEDIUM thrpt 10 571640.454 ± 26499.229 ops/s HpackDecoderBenchmark.decode false true LARGE thrpt 20 92714.555 ± 2292.222 ops/s HpackDecoderBenchmark.decode false false SMALL thrpt 20 1745872.421 ± 6788.840 ops/s HpackDecoderBenchmark.decode false false MEDIUM thrpt 20 490420.323 ± 2455.431 ops/s HpackDecoderBenchmark.decode false false LARGE thrpt 20 84536.200 ± 398.714 ops/s After(bytes): Benchmark (limitToAscii) (sensitive) (size) Mode Cnt Score Error Units HpackDecoderBenchmark.decode true true SMALL thrpt 20 472649.148 ± 7122.461 ops/s HpackDecoderBenchmark.decode true true MEDIUM thrpt 20 66739.638 ± 341.607 ops/s HpackDecoderBenchmark.decode true true LARGE thrpt 20 3139.773 ± 24.491 ops/s HpackDecoderBenchmark.decode true false SMALL thrpt 20 466933.833 ± 4514.971 ops/s HpackDecoderBenchmark.decode true false MEDIUM thrpt 20 66111.778 ± 568.326 ops/s HpackDecoderBenchmark.decode true false LARGE thrpt 20 3143.619 ± 3.332 ops/s HpackDecoderBenchmark.decode false true SMALL thrpt 20 2109995.177 ± 6203.143 ops/s HpackDecoderBenchmark.decode false true MEDIUM thrpt 20 586026.055 ± 1578.550 ops/s HpackDecoderBenchmark.decode false false SMALL thrpt 20 1775723.270 ± 4932.057 ops/s HpackDecoderBenchmark.decode false false MEDIUM thrpt 20 493316.467 ± 1453.037 ops/s HpackDecoderBenchmark.decode false false LARGE thrpt 10 85726.219 ± 402.573 ops/s After(ints): Benchmark (limitToAscii) (sensitive) (size) Mode Cnt Score Error Units HpackDecoderBenchmark.decode true true SMALL thrpt 20 615549.006 ± 5282.283 ops/s HpackDecoderBenchmark.decode true true MEDIUM thrpt 20 86714.630 ± 654.489 ops/s HpackDecoderBenchmark.decode true true LARGE thrpt 20 3984.439 ± 61.612 ops/s HpackDecoderBenchmark.decode true false SMALL thrpt 20 602489.337 ± 5397.024 ops/s HpackDecoderBenchmark.decode true false MEDIUM thrpt 20 88399.109 ± 241.115 ops/s HpackDecoderBenchmark.decode true false LARGE thrpt 20 3875.729 ± 103.057 ops/s HpackDecoderBenchmark.decode false true SMALL thrpt 20 2092165.454 ± 11918.859 ops/s HpackDecoderBenchmark.decode false true MEDIUM thrpt 20 583465.437 ± 5452.115 ops/s HpackDecoderBenchmark.decode false true LARGE thrpt 20 93290.061 ± 665.904 ops/s HpackDecoderBenchmark.decode false false SMALL thrpt 20 1758402.495 ± 14677.438 ops/s HpackDecoderBenchmark.decode false false MEDIUM thrpt 10 491598.099 ± 5029.698 ops/s HpackDecoderBenchmark.decode false false LARGE thrpt 20 85834.290 ± 554.915 ops/s ```	2019-07-02 20:09:44 +02:00