Reduce calls to Source#buffer(StringScanner#rest)#106
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kou merged 1 commit intoruby:masterfrom Jan 20, 2024
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| @source.read if @source.buffer.size<2 | ||
| if @source.buffer[0] == ?< | ||
| if @source.buffer[1] == ?/ | ||
| pattern = @source.buffer[0,2] |
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I think that this is not a pattern. Can we use more suitable name such as buffer and next_data?
Can we remove [0,2]? I think that it's a needless method call.
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| @source.read if @source.buffer.size<2 | ||
| if @source.buffer[0] == ?< | ||
| if @source.buffer[1] == ?/ | ||
| pattern = @source.buffer[0,2] |
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We may want to reduce one more @source.buffer call.
pattern = @source.buffer
if pattern.size < 2
@source.read
pattern = @source.buffer
end
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It worked with this content.
Thank you!
[Why]
`Source#buffer` calling `StringScanner#rest`.
`StringScanner#rest` is slow.
Reduce calls to `Source#buffer`.
## Benchmark
```
RUBYLIB= BUNDLER_ORIG_RUBYLIB= /Users/naitoh/.rbenv/versions/3.3.0/bin/ruby -v -S benchmark-driver /Users/naitoh/ghq/github.com/naitoh/rexml/benchmark/parse.yaml
ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin22]
Calculating -------------------------------------
before after before(YJIT) after(YJIT)
dom 10.639 10.985 16.213 16.221 i/s - 100.000 times in 9.399033s 9.103461s 6.167962s 6.164794s
sax 28.357 29.440 42.900 44.375 i/s - 100.000 times in 3.526479s 3.396688s 2.331024s 2.253511s
pull 32.852 34.210 48.976 51.273 i/s - 100.000 times in 3.043965s 2.923140s 2.041816s 1.950344s
stream 30.821 31.908 43.953 44.697 i/s - 100.000 times in 3.244539s 3.134020s 2.275172s 2.237310s
Comparison:
dom
after(YJIT): 16.2 i/s
before(YJIT): 16.2 i/s - 1.00x slower
after: 11.0 i/s - 1.48x slower
before: 10.6 i/s - 1.52x slower
sax
after(YJIT): 44.4 i/s
before(YJIT): 42.9 i/s - 1.03x slower
after: 29.4 i/s - 1.51x slower
before: 28.4 i/s - 1.56x slower
pull
after(YJIT): 51.3 i/s
before(YJIT): 49.0 i/s - 1.05x slower
after: 34.2 i/s - 1.50x slower
before: 32.9 i/s - 1.56x slower
stream
after(YJIT): 44.7 i/s
before(YJIT): 44.0 i/s - 1.02x slower
after: 31.9 i/s - 1.40x slower
before: 30.8 i/s - 1.45x slower
```
- YJIT=ON : 1.00x - 1.05x faster
- YJIT=OFF : 1.03x - 1.04x faster
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Thanks! |
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Thanks! |
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Reduce calls to
Source#buffer(StringScanner#rest)Why
Source#buffercallingStringScanner#rest.StringScanner#restis slow.Reduce calls to
Source#buffer.Benchmark