perf(rolldown): probe the name map once in ConflictResolver::resolve#9899
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IWANABETHATGUY
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…9899) ## What `ConflictResolver::resolve` is the per-symbol deconfliction primitive (shared by `Renamer` and the cross-chunk export pass) — called once for every top-level symbol in every chunk. Its fast path (the common case where the bare name is free) hashed and walked the `used` map **twice** for the same key: ```rust if !self.used.contains_key(&base) && accept(&base, true) { self.used.insert(base.clone(), 0); // second hash + table walk of `base` return base; } ``` This replaces the `contains_key` + `insert` pair with a single `entry()` probe. Semantics are identical: - `Vacant` + accepted → the old fast path (write the slot we already located) - `Vacant` + vetoed → leave `base` unrecorded, start the suffix search at 1 - `Occupied` → jump past it using its stored counter The clone count is unchanged (the map must own the key either way); the win is **one fewer hash + table walk per symbol** on the hot path. ## Evidence (cargo-asm, release / fat-LTO) Measured on the inlined caller `Renamer::add_symbol_in_root_scope`: | | asm lines | `contains_key` | `insert` | |---|---|---|---| | before | 927 | 1 | 4 | | after | 783 | 0 | 3 | ## Verification - `ConflictResolver` unit tests (incl. the counter-jump / veto edge cases) pass - `topics/deconflict` integration snapshots pass **byte-identically** - clippy clean Companion of #9900, which applies the same single-probe pattern to the `canonical_names` dedup in `add_symbol_in_root_scope`. The two are independent (disjoint files) and can land in either order.
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…er (#9900) ## What `Renamer::add_symbol_in_root_scope` runs once per top-level symbol. On the deconflict path it probed `canonical_names` **twice** for the same `canonical_ref`: - a `contains_key` dedup guard up front (to skip building/allocating the owned name when the ref was already assigned), and - an `insert` at the end. This fuses them into a single `entry()` probe — an `Occupied` slot is the no-op dedup (still skipping the allocation), the `Vacant` slot is written after `resolve`. Behaviour is identical. While here, the JSX-aware "original name" derivation (upper-case the first char when `module.preserve_jsx` is set) was a free function in `renamer.rs` that reached across the crate boundary to recombine three `rolldown_common` primitives for its single caller. It moves to `SymbolRefDb::original_name`, beside its sibling `canonical_name_for_or_original` and the `MustStartWithCapitalLetterForJSX` flag it depends on — which also lets the renamer drop a now-dead `canonical_name` local and the `SymbolRefFlags` import. ## Evidence (cargo-asm, release / fat-LTO) The two single-probe changes compound on the inlined `add_symbol_in_root_scope` (measured cumulatively): | | asm lines | `contains_key` | `RawTable::find` | `insert` | |---|---|---|---|---| | original | 927 | 1 | 1 | 4 | | + #9899 | 783 | 0 | — | 3 | | + this PR | 647 | 0 | 0 | 2 | This PR removes the second `canonical_names` probe (the `RawTable::find` dedup walk) and one more `insert`. ## Verification - `ConflictResolver` unit tests pass - `topics/deconflict` integration snapshots pass **byte-identically** - clippy clean (`rolldown` + `rolldown_common`) Companion of #9899; the two are independent (disjoint files) and can land in either order.
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## [1.1.3] - 2026-06-24 ### 🐛 Bug Fixes - `defer_drop` crashes the browser main thread (#9942) by @shulaoda - camel-case: correct camel case for nested values (#9933) by @kb019 - cli: display --help options in camelCase (#9941) by @IWANABETHATGUY - preserve used re-exports under preserveModules (#9122) (#9934) by @IWANABETHATGUY - watch: make close reentrant in event callbacks (#9904) by @hyf0 - git for windows treats symlink files as regular files (#9915) by @AliceLanniste - dev: cancel pending full reload on build error (#9903) by @h-a-n-a - chunking: pass plugin meta to codeSplitting groups name function (#9267) by @Kyujenius - dev: serve assets emitted during HMR/lazy compile (vite#22596) (#9815) by @h-a-n-a - release: dry-run step no longer publishes binding packages (#9866) by @Boshen ### 🚜 Refactor - rolldown_common: model ModuleId as a classified Path/Virtual/Bare enum (#9927) by @Boshen - remove unused LegacyModuleIdx (#9872) by @shulaoda - remove unused StmtInfos::get_namespace_stmt_info (#9870) by @shulaoda - remove unused Module::as_external_mut (#9871) by @shulaoda - remove unused EcmaAst::is_body_empty (#9869) by @shulaoda - drop dead is_css_module handling in resolve_dependencies (#9867) by @shulaoda - drop redundant with_commonjs on cjs source type (#9868) by @shulaoda ### 📚 Documentation - clarify on drafting PRs (#9952) by @h-a-n-a - update contribution guidelines (#9944) by @fubhy - note Rust crates don't follow semver in AGENTS.md (#9905) by @IWANABETHATGUY - add feedback form (#9159) by @TheAlexLichter ### ⚡ Performance - utils: avoid allocation in default_sanitize_file_name for clean names (#9928) by @Boshen - binding: box once-per-build futures before spawn_future (#9864) by @Boshen - utils: avoid wasted allocation in legitimize_identifier_name (#9926) by @Boshen - rolldown: fuse the canonical-name dedup and insert in the renamer (#9900) by @Boshen - rolldown: probe the name map once in ConflictResolver::resolve (#9899) by @Boshen - cut two heap allocations from wrapped ESM init finalize (#9901) by @Boshen - rolldown_plugin_vite_reporter: hoist invariant out_dir prefix out of reporter loop (#9873) by @shulaoda - drop throwaway Vec in wrapped esm init stmt (#9878) by @shulaoda - borrow owner_filename in build-import-analysis AddDeps (#9874) by @shulaoda ### 🧪 Testing - cover preserveModules named export via namespace re-export (#6010) (#9937) by @IWANABETHATGUY ### ⚙️ Miscellaneous Tasks - deps: update napi to v3.9.4 (#9954) by @shulaoda - reduce noise from CODEOWNERS for trival changes (#9953) by @h-a-n-a - deps: update mimalloc-safe to 0.1.64 (#9950) by @shulaoda - deps: update rollup submodule for tests to v4.62.2 (#9931) by @rolldown-guard[bot] - deps: test mimalloc-safe upstream-mimalloc switch in CI (#9930) by @shulaoda - rolldown_plugin_vite_build_import_analysis: remove unused v2 code path (#9917) by @shulaoda - rolldown_plugin_vite_manifest: remove unused is_enable_v2 code path (#9916) by @shulaoda - rolldown_plugin_vite_asset_import_meta_url: remove unexposed native vite plugin (#9896) by @shulaoda - rolldown_plugin_vite_asset: remove unexposed native vite plugin (#9895) by @shulaoda - rolldown_plugin_vite_css_post: remove unexposed native vite plugin (#9894) by @shulaoda - rolldown_plugin_vite_css: remove unexposed native vite plugin (#9893) by @shulaoda - rolldown_plugin_vite_html_inline_proxy: remove unexposed native vite plugin (#9892) by @shulaoda - rolldown_plugin_vite_html: remove unexposed native vite plugin (#9891) by @shulaoda - deps: update github actions (#9909) by @renovate[bot] - deps: update rust crate oxc_sourcemap to v8.0.2 (#9910) by @renovate[bot] - deps: update npm packages (#9912) by @renovate[bot] - deps: update github actions to v7 (#9913) by @renovate[bot] - deps: update rolldown-plugin-dts to ^0.26.0 (#9897) by @renovate[bot] - remove rolldown_filter_analyzer crate (#9865) by @Boshen ### ❤️ New Contributors * @fubhy made their first contribution in [#9944](#9944) Co-authored-by: shulaoda <165626830+shulaoda@users.noreply.github.com>
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What
ConflictResolver::resolveis the per-symbol deconfliction primitive (shared byRenamerand the cross-chunk export pass) — called once for every top-level symbol in every chunk.Its fast path (the common case where the bare name is free) hashed and walked the
usedmap twice for the same key:This replaces the
contains_key+insertpair with a singleentry()probe. Semantics are identical:Vacant+ accepted → the old fast path (write the slot we already located)Vacant+ vetoed → leavebaseunrecorded, start the suffix search at 1Occupied→ jump past it using its stored counterThe clone count is unchanged (the map must own the key either way); the win is one fewer hash + table walk per symbol on the hot path.
Evidence (cargo-asm, release / fat-LTO)
Measured on the inlined caller
Renamer::add_symbol_in_root_scope:contains_keyinsertVerification
ConflictResolverunit tests (incl. the counter-jump / veto edge cases) passtopics/deconflictintegration snapshots pass byte-identicallyCompanion of #9900, which applies the same single-probe pattern to the
canonical_namesdedup inadd_symbol_in_root_scope. The two are independent (disjoint files) and can land in either order.