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Reduce calls to Source#buffer
(StringScanner#rest
)
#106
Conversation
lib/rexml/parsers/baseparser.rb
Outdated
@@ -349,8 +349,9 @@ def pull_event | |||
end | |||
begin | |||
@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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OK.
I see.
lib/rexml/parsers/baseparser.rb
Outdated
@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! |
Thanks! |
Reduce calls to
Source#buffer
(StringScanner#rest
)Why
Source#buffer
callingStringScanner#rest
.StringScanner#rest
is slow.Reduce calls to
Source#buffer
.Benchmark