refactor(allocator): replace ChunkFooter::is_empty with free function#21772
Merged
graphite-app[bot] merged 1 commit intomainfrom Apr 26, 2026
Conversation
This was referenced Apr 26, 2026
Member
Author
This was referenced Apr 26, 2026
Merged
Merging this PR will not alter performance
Comparing 
Footnotes
|
Contributor
There was a problem hiding this comment.
Pull request overview
This PR refactors the arena allocator’s “empty chunk footer” sentinel check by removing the private ChunkFooter::is_empty method and introducing a free function that checks sentinel-ness via pointer equality, avoiding reference conversions solely for comparison.
Changes:
- Removed
ChunkFooter::is_empty(&self)and addedis_empty_footer(NonNull<ChunkFooter>)inarena/mod.rs. - Updated chunk-walking/reset/drop/allocation code paths to use
is_empty_footerinstead of deref + method calls. - Reduced unnecessary
NonNull::as_ref()usage in iterator/byte-counting logic when only sentinel checks are needed.
Reviewed changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| crates/oxc_allocator/src/arena/mod.rs | Replaces the ChunkFooter::is_empty method with the is_empty_footer free function based on pointer equality to the canonical sentinel. |
| crates/oxc_allocator/src/arena/drop.rs | Updates reset, chunk list deallocation, and related assertions to use is_empty_footer. |
| crates/oxc_allocator/src/arena/chunks.rs | Refactors chunk iteration and used_bytes/allocated_bytes logic to check sentinel via is_empty_footer before dereferencing. |
| crates/oxc_allocator/src/arena/alloc_impl.rs | Uses is_empty_footer to avoid touching the static empty footer’s interior mutability (prevents potential data race) without needing a ref conversion to check emptiness. |
cd3bb51 to
efe454e
Compare
80a6c06 to
b8065a7
Compare
This was referenced Apr 26, 2026
Contributor
Merge activity
|
…on (#21772) Remove `ChunkFooter::is_empty` method and add an `is_empty_footer` free function instead. This is beneficial as it removes the need for unsafe pointer to reference conversions.
efe454e to
7896bd0
Compare
b8065a7 to
f8422e2
Compare
Base automatically changed from
om/04-25-perf_allocator_allocator_used_bytes_do_not_use_chunk_iterator
to
main
April 26, 2026 22:02
This file contains hidden or 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
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.
Remove
ChunkFooter::is_emptymethod and add anis_empty_footerfree function instead. This is beneficial as it removes the need for unsafe pointer to reference conversions.