perf: optimize module concatenation root search#14815
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📦 Binary Size-limit
❌ Size increased by 24.00KB from 66.60MB to 66.62MB (⬆️0.04%) |
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Rsdoctor Bundle Diff AnalysisFound 5 projects in monorepo, 0 projects with changes. 📊 Quick Summary
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Merging this PR will improve performance by 3.03%
Performance Changes
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📝 Benchmark detail: Open
Base persistent cache hit rate: 👍 Current persistent cache hit rate: 👍 |
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Summary
TL;DR: remove repeated module-graph work from
ModuleConcatenationPluginwhile preserving its root-by-root decisions, warning text, and deterministic ordering.(module, runtime)for the lifetime of one optimization passRuntimeSpecMapfor runtime-keyed cachesexperiments.deferImportis disabledrust@create_concatenate_module_bailoutsfor cross-chunk and recursive importer-failure coverageThe hot path runs once per candidate across thousands of possible roots. Previously, identical incoming sets were repeatedly collected, sorted, cloned, and allocated for each root.
Performance
Large synthetic support application, cold release-distribution validation with server concatenation enabled and caches cleared before every sample:
@rspack/core2.1.0: 58.08 s median (five runs)This distribution-level comparison includes intervening main-branch changes; the plugin-specific profile below isolates the concatenation gain. Published 2.1.0 was 29.20 s median with server concatenation disabled, confirming that enabling the old implementation nearly doubled this app’s build time.
Large synthetic support application, no-trace plugin profiles:
ModuleConcatenationPlugin: 10.47 s → 1.60–1.64 s (~84.5% faster)ModuleConcatenationPlugin, latest optimization versus the earlier PR revision: 5.19 s → 0.36 s (~93% faster)The first cache pass improved the comparable shared-roots CodSpeed case from 16.835 ms to 14.121 ms (-15.7%, final rerun 14.511 ms) with no significant change in the disjoint-root case. Current-head CodSpeed reports a 3.03% aggregate improvement; the existing
rust@create_concatenate_modulecase improved 14.4 ms → 13.9 ms (3.65% faster). The ecosystem benchmark completed successfully: every reported wall-time case improved (0.87–6.80%), with persistent-cache hit rates preserved.Correctness and risk
Veccollection and sequential graph writes preserve diagnostics orderReviewer guide
RuntimeIdentifierCache,CachedIncomingModules, andNoRuntimeModuleCache: cache key and lifetime changes.ModuleConcatenationPlugin::try_to_add: shared incoming analysis with root-specific compatibility decisions.optimize_chunk_modules_impl: scratch-buffer reuse and ordered parallel bailout formatting.compilation_stages.rs: unchanged historical shared-roots case plus the separate bailout-heavy case.Testing
pnpm run build:binding:releasepnpm run build:cli:devcargo test -p rspack_plugin_javascript— 33 passedStatsOutput.test.js— 153 passed-D warningspnpm run format:rsandpnpm run format:jspnpm run test:unit— 8,806 passed, 4 skipped; 3 acknowledged pre-existing browserslist fixture failures remainrspack_cacheableRelated links
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