Avoid allocations in Decoder::read_str.
#37064
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r? @erickt (rust_highfive has picked a reviewer for you, use r? to override) |
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r? @eddyb |
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(This is a carry-over of #37022 because I borked my git clone.) |
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@bors r+ |
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📌 Commit d6117f8 has been approved by |
`opaque::Decoder::read_str` is very hot within `rustc` due to its use in the reading of crate metadata, and it currently returns a `String`. This commit changes it to instead return a `Cow<str>`, which avoids a heap allocation. This change reduces the number of calls to `malloc` by almost 10% in some benchmarks. This is a [breaking-change] to libserialize.
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@eddyb: bleh, I pushed with some uncommitted changes. New version should be better. |
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@bors r+ |
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📌 Commit b043e11 has been approved by |
sophiajt
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Oct 11, 2016
Avoid allocations in `Decoder::read_str`. `opaque::Decoder::read_str` is very hot within `rustc` due to its use in the reading of crate metadata, and it currently returns a `String`. This commit changes it to instead return a `Cow<str>`, which avoids a heap allocation. This change reduces the number of calls to `malloc` by almost 10% in some benchmarks. This is a [breaking-change] to libserialize.
alexcrichton
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Oct 12, 2016
Avoid allocations in `Decoder::read_str`. `opaque::Decoder::read_str` is very hot within `rustc` due to its use in the reading of crate metadata, and it currently returns a `String`. This commit changes it to instead return a `Cow<str>`, which avoids a heap allocation. This change reduces the number of calls to `malloc` by almost 10% in some benchmarks. This is a [breaking-change] to libserialize.
bors
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Oct 12, 2016
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opaque::Decoder::read_stris very hot withinrustcdue to its use inthe reading of crate metadata, and it currently returns a
String. Thiscommit changes it to instead return a
Cow<str>, which avoids a heapallocation.
This change reduces the number of calls to
mallocby almost 10% insome benchmarks.
This is a [breaking-change] to libserialize.