Avoid allocations in Decoder::read_str.
#37064
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
r? @erickt (rust_highfive has picked a reviewer for you, use r? to override) |
|
r? @eddyb |
|
(This is a carry-over of #37022 because I borked my git clone.) |
|
@bors r+ |
|
📌 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.
|
@eddyb: bleh, I pushed with some uncommitted changes. New version should be better. |
|
@bors r+ |
|
📌 Commit b043e11 has been approved by |
sophiajt
pushed a commit
to sophiajt/rust
that referenced
this pull request
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
added a commit
to alexcrichton/rust
that referenced
this pull request
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
added a commit
that referenced
this pull request
Oct 12, 2016
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
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.