Performance improvement and benchmark

[indutny]

n/t

cc @bnoordhuis

[chrisdickinson]

base benchmarks (as of 3f1a05a)

$ rm -rf bench; make clean; make -j8; make bench; ./bench
rm -f *.o *.a tags test test_fast test_g \
        http_parser.tar libhttp_parser.so.* \
        url_parser url_parser_g parsertrace parsertrace_g
cc -I. -DHTTP_PARSER_STRICT=1  -Wall -Wextra -Werror -O0 -g  -c http_parser.c -o http_parser_g.o
cc -I. -DHTTP_PARSER_STRICT=1  -Wall -Wextra -Werror -O0 -g  -c test.c -o test_g.o
cc -I. -DHTTP_PARSER_STRICT=0  -Wall -Wextra -Werror -O3  -c http_parser.c
cc -I. -DHTTP_PARSER_STRICT=0  -Wall -Wextra -Werror -O3  -c test.c -o test.o
cc -Wall -Wextra -Werror -O0 -g   http_parser_g.o test_g.o -o test_g
cc -Wall -Wextra -Werror -O3   http_parser.o test.o -o test_fast
./test_g
http_parser v2.3.0 (0x020300)
sizeof(http_parser) = 32
response scan 1/2  100%
response scan 2/2  100%
responses okay
request scan 1/4  100%
request scan 2/4  100%
request scan 3/4  100%
request scan 4/4  100%
requests okay
./test_fast
http_parser v2.3.0 (0x020300)
sizeof(http_parser) = 32
response scan 1/2  100%
response scan 2/2  100%
responses okay
request scan 1/4  100%
request scan 2/4  100%
request scan 3/4  100%
request scan 4/4  100%
requests okay
cc -I. -DHTTP_PARSER_STRICT=0  -Wall -Wextra -Werror -O3  -Wno-unused-parameter -c bench.c -o bench.o
cc -Wall -Wextra -Werror -O3  -Wno-unused-parameter  http_parser.o bench.o -o bench
Benchmark result:
Took 17.883043 seconds to run
279594.468750 req/sec

bench as of 9bf763e

$ rm -rf bench; make clean; make -j8; make bench; ./bench
rm -f *.o *.a tags test test_fast test_g \
        http_parser.tar libhttp_parser.so.* \
        url_parser url_parser_g parsertrace parsertrace_g
cc -I. -DHTTP_PARSER_STRICT=1  -Wall -Wextra -Werror -O0 -g  -c http_parser.c -o http_parser_g.o
cc -I. -DHTTP_PARSER_STRICT=1  -Wall -Wextra -Werror -O0 -g  -c test.c -o test_g.o
cc -I. -DHTTP_PARSER_STRICT=0  -Wall -Wextra -Werror -O3  -c http_parser.c
cc -I. -DHTTP_PARSER_STRICT=0  -Wall -Wextra -Werror -O3  -c test.c -o test.o
cc -Wall -Wextra -Werror -O0 -g   http_parser_g.o test_g.o -o test_g
cc -Wall -Wextra -Werror -O3   http_parser.o test.o -o test_fast
./test_g
http_parser v2.3.0 (0x020300)
sizeof(http_parser) = 32
response scan 1/2  100%
response scan 2/2  100%
responses okay
request scan 1/4  100%
request scan 2/4  100%
request scan 3/4  100%
request scan 4/4  100%
requests okay
./test_fast
http_parser v2.3.0 (0x020300)
sizeof(http_parser) = 32
response scan 1/2  100%
response scan 2/2  100%
responses okay
request scan 1/4  100%
request scan 2/4  100%
request scan 3/4  100%
request scan 4/4  100%
requests okay
cc -I. -DHTTP_PARSER_STRICT=0  -Wall -Wextra -Werror -O3  -Wno-unused-parameter -c bench.c -o bench.o
cc -Wall -Wextra -Werror -O3  -Wno-unused-parameter  http_parser.o bench.o -o bench
Benchmark result:
Took 5.048899 seconds to run
990314.875000 req/sec

[bnoordhuis]

Needs some clarification about end-of-line scanning but apart from that LGTM and nice work. As discussed on IRC, scanning for known headers could probably be optimized some more using e.g. Boyer-Moore skip tables.

[indutny]

@bnoordhuis please take a look at latest commit, it should fix the issue with end-of-line scan.

[indutny]

All landed in 3f1a05a, 6132d1f, 0cb0ee6, 2630060, c6097e1, 0097de5, 959f4cb. Thank you!