perf(formatter_core): avoid per-call Vec work-stack in soft-line removal#23775
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…moval `RemoveSoftLinesBuffer::write_element` and `clean_interned` each allocated a heap `Vec<FormatElement>` on every call so the (rare) `BestFitting` arm could expand into multiple elements. For every other variant the loop ran exactly once. Handle the single element directly and recurse for `BestFitting`; depth is bounded by `best_fitting!` nesting. Per-element body of `clean_interned` moved into a `push_cleaned_element` helper so the two state machines use the same control strategy. `cargo allocs` formatter sys-alloc counts: | File | before | after | | | ---------------- | ------: | ------: | ----: | | antd.js | 83,239 | 80,727 | -3.0% | | App.tsx | 7,588 | 7,187 | -5.3% | | kitchen-sink.tsx | 20,458 | 19,037 | -6.9% | | checker.ts | 18,642 | 17,705 | -5.0% |
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Thanks too. Updated comments and alloc snaps. 👍🏻
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# Oxlint ### 🚀 Features - 0433a83 linter/eslint/no-inner-declarations: Add `namespaces` option (#24044) (Boshen) - 92f154a oxlint,oxfmt: Auto-discover `.mts` config files (#24357) (camc314) - 8c1d74b linter/import/no-duplicates: Add autofix logic (#24273) (Cole Ellison) ### 🐛 Bug Fixes - 0b086de linter/jest/prefer-lowercase-title: False positive when `lowercaseFirstCharacterOnly` is false (#24414) (Connor Shea) - 097cb95 linter: Allow `vite-plus/test` and `@effect as Vitest source (#24196) (Liang) - 8337835 linter: Error on `ignorePatterns` that cannot match files aoutside the config directory (#24341) (leaysgur) - 9ba30e5 linter/oxc/bad-replace-all-arg: Add note to enhance diagnostic (#24346) (camc314) - 2ce5a33 linter: Resolve `ignorePatterns` relative to the config dir (#24339) (leaysgur) - ab90eed linter/eslint/no-loop-func: Do not error on catch variables (#24316) (Chris Opperwall) - b67f0a6 linter/eslint/no-unused-vars: Count default parameter updates as usage (#24323) (camc314) - d193f8e linter: Detect Junie agent env vars (#24277) (Jeevan Mohan Pawar) - 2aecf60 linter/eslint/no-unreachable: Handle `break` in switch stmts correctly (#24260) (camc314) ### ⚡ Performance - 7f80cac linter/vue/prop-name-casing: Precompile `ignoreProps` regex pattern (#24413) (connorshea) - 6272051 linter/typescript/no-require-imports: Compile allow patterns once (#24417) (connorshea) - fb1edf1 linter: Compute comment fix span only for directive comments (#24419) (connorshea) - 33805b9 linter/jsdoc/require-param: Compile checkTypesPattern regex once (#24420) (connorshea) - 8de6fca linter/jest/valid-title: Compile disallowedWords regex once (#24412) (Connor Shea) - 4a0d8dc linter/eslint/no-underscore-dangle: Avoid String clone per identifier (#24371) (Ian Macalinao) - f3ab04c linter/typescript/consistent-type-imports: Remove redundant Vec per violation (#24370) (Ian Macalinao) - 4d2d78d linter/typescript/prefer-ts-expect-error: Avoid String clone per comment (#24369) (Ian Macalinao) # Oxfmt ### 🚀 Features - 3a7fe74 formatter_css: Update oxc-css-parser to 0.0.7 (#24434) (leaysgur) - 0173cd3 formatter_css: Format Less :extend and merge props (#24358) (leaysgur) - 92f154a oxlint,oxfmt: Auto-discover `.mts` config files (#24357) (camc314) - df250df formatter: Support `quoteProps` for TS enum and methods (#24309) (leaysgur) - a9a5cd6 formatter_core: Expose `SourceText::as_str()` (#24281) (leaysgur) ### 🐛 Bug Fixes - 162bddf formatter: Add required parens for conditional type in type parameter constraint (#24450) (leaysgur) - 2d22a91 formatter: Determine type cast target from span instead of lexical scan (#24447) (leaysgur) - 25306e9 formatter: Do not add extra parens with type cast comment (#24444) (leaysgur) - bd6edfe formatter: Break arrow signature that exactly fills the line when cond body may hug (#24440) (leaysgur) - a99ef41 formatter: Keep quotes on method signature named new (#24432) (leaysgur) - fcc28df formatter_css: Keep glued-braket-value tight (#24352) (leaysgur) - 8337835 linter: Error on `ignorePatterns` that cannot match files aoutside the config directory (#24341) (leaysgur) - b7c7e15 formatter: Add parens for import and private field in new callee chain (#24320) (leaysgur) - 0c8f6e4 formatter: Update detect_code_removal for #24309 (#24314) (leaysgur) - a85aad0 formatter: Fix member-chain and non-null parens (#24312) (leaysgur) - 1c29c73 formatter: Preserve `TSNonNullExpression` in chain expression (#24311) (leaysgur) - 8933c0e formatter: Keep comment inside of empty `switch` block (#24308) (leaysgur) - ec26af2 formatter: Preserve blank lines between JSX attrs (#24290) (leaysgur) - 70bd54d formatter: Keep arrow function body comment (#24287) (leaysgur) - 415fe1e oxfmt: Error on ignorePatterns that cannot match files outside the config directory (#24286) (leaysgur) - eeabc4a formatter_css: Bail on EOF-recovered parse errors (#24282) (leaysgur) - 42ec8de formatter: Keep comments inside surviving parens and suppressed statement terminators (#24253) (leaysgur) - 1343779 formatter: Keep comment inline for empty statements (#24249) (leaysgur) - b996579 formatter: Print ; before trailing comments part 2 (#24246) (leaysgur) - 4f86e8c formatter: Print `;` before trailing comments (#24244) (leaysgur) - 01252e4 formatter: Add or remove parens for `let` declaration (#24215) (leaysgur) ### ⚡ Performance - eeb1913 formatter_core: Avoid per-call `Vec` work-stack in soft-line removal (#23775) (Marius Schulz) - a2f255b formatter: Use `SmallVec` for `MemberChain` collections (#23776) (Marius Schulz) ### 📚 Documentation - b52d0f5 formatter: Add TODO comment about unsound code (#24372) (overlookmotel) Co-authored-by: Boshen <[email protected]>
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What
RemoveSoftLinesBuffer::write_elementandclean_internedeach allocate a heapVecwork-stack on every call, even though the loop body runs exactly once for every variant exceptBestFitting.Change
Match the element directly and recurse for the
BestFittingarm instead of maintaining an explicit stack. Theclean_internedper-element body moves into apush_cleaned_elementhelper so both soft-line-removal state machines use the same control strategy.Recursion depth is bounded by
best_fitting!nesting in the most-flat variant, which is a strict subset of AST expression nesting depth (the formatter already recurses through that viaFormat::fmt).Verification
cargo clippy -p oxc_formatter_core(+--features test_harness) — cleancargo test -p oxc_formatter_core— 28 passedcargo test -p oxc_formatter --test mod— 294 passedcargo run -p oxc_prettier_conformance— snapshots unchangedcargo allocs— snapshot updatedThis PR was assisted by Claude Code.