Avoid reallocations for reading qualified names#68
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Running https://github.com/drott/xml-rs/blob/parserBench/tests/streaming.rs#L235 on my machine this gives me a 2.8% improvement in runs per second on running this parsing benchmark that is similar to the one we use for Blink. The existing allocation in 
is gone: 
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Looks like there are still correctness issues, I'll look into that. |
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Qualified names accumulate into buf, but drop their scratch space after every completion of reading a qualified name. At the end of reading a qualified name, the scratch space only needs to be read by reference. The allocation of the value returned to the API client happens in OwnedName. By using a separate scratch space `qualified_name_buf`, we can operate on the same scratch space string for each time reading a qualified name. Results in a 2.8% speedup in a local measurement against a test similar to [1]. [1] https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/perf_tests/parser/xml-parser.html;l=8?q=xml-parser.html
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I believe this is ready for review now. |
kornelski
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Changes merged in upstream but no version released yet. Covers kornelski/xml-rs#68 Bug: 470367156 Change-Id: I1e2b729c7e2e61aff25b6c84e75f298718061df2 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7544561 Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org> Auto-Submit: Dominik Röttsches <drott@chromium.org> Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org> Cr-Commit-Position: refs/heads/main@{#1579537} NOKEYCHECK=True GitOrigin-RevId: f41e0fc863c04deab1f3e4bb3be97251842b87cc
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Changes merged in upstream but no version released yet. Covers kornelski/xml-rs#68 Bug: 470367156 Change-Id: I1e2b729c7e2e61aff25b6c84e75f298718061df2 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7544561 Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org> Auto-Submit: Dominik Röttsches <drott@chromium.org> Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org> Cr-Commit-Position: refs/heads/main@{#1579537}
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Qualified names accumulate into buf, but drop their scratch space after every completion of reading a qualified name. At the end of reading a qualified name, the scratch space only needs to be read by reference. The allocation of the value returned to the API client happens in OwnedName.
By using a separate scratch space
qualified_name_buf, we can operate on the same scratch space string for each time reading a qualified name.