perf(router-core): keep search middleware collection optimized by schiller-manuel · Pull Request #8385 · TanStack/router

schiller-manuel · 2026-09-11T23:46:18Z

Stacked on #8382.

Mechanism

CodSpeed's memory instrument flagged the mem client interrupted-navigations peak-memory benchmark on the location-reuse changes (#8370): react +14.6%, vue +29.8%, solid +10.8% versus base fc31a1d. Under CodSpeed's worker flags (--no-opt --predictable, single threaded) that benchmark's peak is set by a synchronous Maglev compile that happens inside the measured run.

The function is getSearchMiddlewares in packages/router-core/src/router.ts. In both base and head it is compiled during the preparation calls and then deoptimized (wrong map) on the first named property load off a route's options. In base its only caller was the small applySearchMiddleware, which Maglev compiled right afterwards and inlined it into, so the callee never tiered up again. Since #8370, build calls getSearchMiddlewares directly and does not inline it, so it becomes hot again during the measured run and recompiles there (about four 32 KB zone segments), setting the peak.

Iterating destRoutes with a counted loop instead of for...of makes the function compile once during preparation and never deoptimize, so there is no recompilation in the measured window. Middleware order and live route-option reads are unchanged. Hoisting the option reads alone did not help (and made the peak worse). This builds on the earlier perf(router-core): reduce middleware compilation memory commit in this stack, which already separated getSearchMiddlewares from the recursive middleware execution for the same class of reason.

Diff

 // Keep this separate from recursive execution to limit JIT compiler memory.
+// A counted loop instead of `for...of`: Maglev's inlined array iteration
+// deoptimizes on route option shapes and recompiles later, whereas indexed
+// reads stay optimized once compiled.
 function getSearchMiddlewares(
   destRoutes: ReadonlyArray<AnyRoute>,
   includeValidateSearch: boolean | undefined,
 ) {
   const middlewares = [] as Array<SearchMiddleware<any>>

-  for (const route of destRoutes) {
-    const routeOptions = route.options
+  for (let i = 0; i < destRoutes.length; i++) {
+    const routeOptions = destRoutes[i]!.options
     if ('search' in routeOptions) {

Plus a @tanstack/router-core patch changeset.

Measurements

Peak outstanding malloc bytes in the measured run, reproduced locally with a malloc interposer under CodSpeed's exact worker flags (@codspeed/core getV8Flags() for analysis mode plus the repo's flags from benchmarks/memory/runtime.ts), mirroring the plugin's seven preparation calls. These are local macOS arm64 / Node 24.8.0 native-allocation measurements, not a Linux CodSpeed CI run. Results are byte-deterministic across builds.

framework	base `a7427d6`	head `62ed0ce` (#8370 tip)	with this fix
react	248,880	287,760 (+15.6%)	248,944 (+0.03%)
vue	256,704	292,656 (+14.0%)	256,640 (−0.02%)
solid	287,408	288,240 (+0.3%)	287,632 (+0.08%)

Bundle

react-router.minimal measured with pnpm benchmark:bundle-size:run against a baseline taken at the stack top (f5c4a4d7ce):

metric	baseline	candidate	delta
gzip	86,004	86,012	+8
initial gzip	85,864	85,874	+10
raw	267,901	267,916	+15
brotli	75,039	75,013	−26

Verification

@tanstack/router-core:test:unit — 133 files, 3303 passed, 4 expected fail
@tanstack/router-core:test:types — clean on all TypeScript versions (5.6–7.0)
@tanstack/router-core:test:eslint — 0 errors, 27 warnings. One warning is new and inherent to this change: @typescript-eslint/prefer-for-of at the counted loop. The rule is warning-level and the same file already carries an identical accepted warning for the counted loop in matchRoutesInternal (line 1774). No disable comment was added.
git diff --check and prettier on the changed files — clean

Summary by CodeRabbit

Bug Fixes
- Improved navigation performance and memory usage by preventing unnecessary runtime recompilation when processing search middleware across navigations.
Release
- Included a patch release for the router core package.

coderabbitai · 2026-09-11T23:46:25Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Advanced

Run ID: a703aea6-d6c2-4a77-bae7-99c71c4c496c

📥 Commits

Reviewing files that changed from the base of the PR and between f5c4a4d and 6aec14d.

📒 Files selected for processing (2)

.changeset/steady-loops-compile.md
packages/router-core/src/router.ts

Included review availability: Your plan provides up to 10 included reviews per hour; 8 remain after this review.

📝 Walkthrough

Walkthrough

The search middleware collection now uses an indexed counted loop over destination routes. A changeset records a patch release for @tanstack/router-core and documents the JIT optimization rationale.

Changes

Search middleware optimization

Layer / File(s)	Summary
Counted loop and release metadata `packages/router-core/src/router.ts`, `.changeset/steady-loops-compile.md`	`getSearchMiddlewares` now uses indexed iteration without changing middleware behavior. The changeset declares a patch release and documents the optimization.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~5 minutes

Change: Refactor

Suggested reviewers: sheraff

Merge Risk: ⚪ Minimal · up to 65b66

The indexed loop preserves the existing middleware behavior, and the PR is ready to merge after normal checks.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main performance optimization in router-core.
Description check	✅ Passed	The description provides detailed change motivation, implementation details, benchmark results, verification results, and release impact. It does not reproduce the template checklist headings or check…
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files. (1 skipped: 1 …
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

Create stacked PR
Commit on current branch

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch schiller-manuel-search-middleware-compile-memory

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nx-cloud · 2026-09-11T23:53:29Z

View your CI Pipeline Execution ↗ for commit 65b6654

Command	Status	Duration	Result
`nx run-many --target=build --exclude=examples/*...`	✅ Succeeded	1m 58s	View ↗

☁️ Nx Cloud last updated this comment at 2026-09-12 22:32:14 UTC

github-actions · 2026-09-11T23:57:09Z

Bundle Size Benchmarks

Commit: 1ddd64e5e656
Measured at: 2026-09-12T22:10:35.503Z
Baseline source: history:ae6853592904
Dashboard: bundle-size history

The following scenarios have bundle-size changes compared with the baseline:

Scenario	Current (gzip)	Initial (gzip)	Raw	Brotli	Trend
`react-router.minimal`	84.0 KiB +18 B	83.9 KiB +15 B	261.6 KiB -695 B	73.3 KiB +63 B	█████▁▁▁▁▁▁▂
`react-router.full`	87.5 KiB +38 B	87.4 KiB +40 B	273.3 KiB -703 B	76.2 KiB +53 B	█████▂▂▂▂▂▁▃
`solid-router.minimal`	33.4 KiB -19 B	33.3 KiB -19 B	95.9 KiB -832 B	30.2 KiB -8 B	▅█████████▆▁
`solid-router.full`	38.3 KiB +11 B	38.2 KiB +9 B	110.6 KiB -831 B	34.5 KiB +47 B	▂▅▅▅▅▅▅▅▅▅▁█
`vue-router.minimal`	49.5 KiB -86 B	49.4 KiB -84 B	137.1 KiB -1.2 KiB	44.8 KiB -83 B	█████▃▃▃▃▃▃▁
`vue-router.full`	55.1 KiB -79 B	55.0 KiB -78 B	155.3 KiB -1.2 KiB	49.7 KiB -111 B	█████▃▃▃▃▃▂▁
`react-start.minimal`	96.9 KiB +58 B	96.8 KiB +56 B	303.9 KiB -690 B	84.1 KiB +60 B	█████▁▁▁▁▁▁▄
`react-start.query-integration`	104.3 KiB +45 B	104.1 KiB +46 B	330.4 KiB -698 B	90.4 KiB +23 B	█████▁▁▁▁▁▁▄
`react-start.deferred-hydration`	97.7 KiB +54 B	96.8 KiB +54 B	305.3 KiB -690 B	84.8 KiB +21 B	█████▁▁▁▁▁▁▄
`react-start.full`	100.1 KiB +48 B	100.0 KiB +46 B	313.6 KiB -709 B	86.8 KiB +105 B	█████▁▁▁▁▁▁▃
`react-start.rsbuild.minimal`	100.2 KiB +44 B	100.0 KiB +44 B	314.3 KiB -618 B	86.5 KiB +64 B	█████▁▁▁▁▁▁▃
`react-start.rsbuild.minimal-iife`	100.6 KiB +52 B	100.4 KiB +52 B	315.2 KiB -601 B	86.9 KiB +152 B	█████▁▁▁▁▁▁▄
`react-start.rsbuild.full`	103.5 KiB +67 B	103.3 KiB +67 B	324.3 KiB -614 B	89.2 KiB -4 B	█████▁▁▁▁▁▁▄
`solid-start.minimal`	46.4 KiB +39 B	46.3 KiB +37 B	137.1 KiB -832 B	41.2 KiB +42 B	▃▂▂▂▂▂▂▂▂▂▁█
`solid-start.deferred-hydration`	49.4 KiB +20 B	46.3 KiB +21 B	144.4 KiB -830 B	44.0 KiB +54 B	▁▃▃▃▃▃▃▃▃▃▃█
`solid-start.full`	51.4 KiB +35 B	51.3 KiB +33 B	152.5 KiB -830 B	45.6 KiB +70 B	▂▂▂▂▂▂▂▂▂▂▁█
`vue-start.minimal`	65.6 KiB -91 B	65.5 KiB -90 B	188.0 KiB -1.2 KiB	58.5 KiB +42 B	█████▃▃▃▃▃▃▁
`vue-start.full`	69.5 KiB -59 B	69.4 KiB -56 B	200.3 KiB -1.2 KiB	61.7 KiB -49 B	█████▂▂▂▂▂▂▁

Current gzip tracks all emitted client JS chunks. Initial gzip tracks only the entry/import graph. Trend sparkline is historical current gzip ending with this PR measurement; lower is better.

github-actions · 2026-09-12T00:02:31Z

🚀 Changeset Version Preview

7 package(s) bumped directly, 22 bumped as dependents.

🟩 Patch bumps

Package	Version	Reason
`@tanstack/history`	1.162.3 → 1.162.4	Changeset
`@tanstack/react-router`	1.170.35 → 1.170.36	Changeset
`@tanstack/router-core`	1.171.29 → 1.171.30	Changeset
`@tanstack/router-devtools-core`	1.168.1 → 1.168.2	Changeset
`@tanstack/solid-router`	1.170.33 → 1.170.34	Changeset
`@tanstack/start-server-core`	1.169.34 → 1.169.35	Changeset
`@tanstack/vue-router`	1.170.32 → 1.170.33	Changeset
`@tanstack/react-router-devtools`	1.167.1 → 1.167.2	Dependent
`@tanstack/react-start`	1.168.52 → 1.168.53	Dependent
`@tanstack/react-start-client`	1.168.33 → 1.168.34	Dependent
`@tanstack/react-start-rsc`	0.1.51 → 0.1.52	Dependent
`@tanstack/react-start-server`	1.167.40 → 1.167.41	Dependent
`@tanstack/router-cli`	1.167.35 → 1.167.36	Dependent
`@tanstack/router-devtools`	1.167.1 → 1.167.2	Dependent
`@tanstack/router-generator`	1.167.35 → 1.167.36	Dependent
`@tanstack/router-plugin`	1.168.37 → 1.168.38	Dependent
`@tanstack/router-vite-plugin`	1.167.37 → 1.167.38	Dependent
`@tanstack/solid-router-devtools`	1.167.1 → 1.167.2	Dependent
`@tanstack/solid-start`	1.168.50 → 1.168.51	Dependent
`@tanstack/solid-start-client`	1.168.32 → 1.168.33	Dependent
`@tanstack/solid-start-server`	1.167.39 → 1.167.40	Dependent
`@tanstack/start-client-core`	1.170.29 → 1.170.30	Dependent
`@tanstack/start-plugin-core`	1.171.42 → 1.171.43	Dependent
`@tanstack/start-static-server-functions`	1.167.34 → 1.167.35	Dependent
`@tanstack/start-storage-context`	1.167.31 → 1.167.32	Dependent
`@tanstack/vue-router-devtools`	1.167.1 → 1.167.2	Dependent
`@tanstack/vue-start`	1.168.49 → 1.168.50	Dependent
`@tanstack/vue-start-client`	1.167.35 → 1.167.36	Dependent
`@tanstack/vue-start-server`	1.167.39 → 1.167.40	Dependent

pkg-pr-new · 2026-09-12T00:05:49Z

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commit: 65b6654

codspeed · 2026-09-12T00:28:36Z

Merging this PR will improve performance by 18.29%

⚠️

Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 3 improved benchmarks
✅ 177 untouched benchmarks

Performance Changes

	Mode	Benchmark	`BASE`	`HEAD`	Efficiency
⚡	Memory	`mem client interrupted-navigations (vue)`	282.9 KB	218.3 KB	+29.6%
⚡	Memory	`mem client interrupted-navigations (react)`	248.4 KB	216 KB	+15.03%
⚡	Memory	`mem client interrupted-navigations (solid)`	280.6 KB	252.8 KB	+11.01%

Tip

Curious why performance improved? Comment @codspeedbot explain why performance improved on this PR, or directly use the CodSpeed MCP with your agent.

_{Comparing schiller-manuel-search-middleware-compile-memory (65b6654) with schiller-manuel-remove-build-location-sharing (f5c4a4d)¹}

No successful run was found on schiller-manuel-remove-build-location-sharing (e14d907) during the generation of this report, so 3adfe92 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

CodSpeed's memory instrument flagged the interrupted-navigations client benchmark on the location-reuse changes (react +14.6%, vue +29.8%, solid +10.8% peak memory). Under its worker flags (`--no-opt --predictable`, single threaded) that benchmark's peak is set by a synchronous Maglev compile that happens inside the measured run. `getSearchMiddlewares` is compiled during the preparation calls and then deoptimized on the first property load off a route's options. Before, its only caller was the small `applySearchMiddleware`, which Maglev compiled next and inlined it into, so the callee never tiered up again. Since `build` calls it directly and does not inline it, it became hot again during the measured run, and its recompilation (about four 32 KB zone segments) set the peak. Iterating `destRoutes` with a counted loop instead of `for...of` keeps the function optimized once compiled: no deoptimization and no recompilation in the measured window. Middleware order and live route-option reads are unchanged. Hoisting the option reads alone did not help. Local reproduction with a malloc interposer, CodSpeed's worker flags and seven preparation calls, macOS arm64 / Node 24.8.0 (deterministic peaks): - react: 248880 (base) -> 287760 (+15.6%) -> 248944 with this change - vue: 256704 -> 292656 (+14.0%) -> 256640 - solid: 287408 -> 288240 (+0.3%) -> 287632 These are local native allocations, not a new Linux CodSpeed CI run. Bundle (react-router.minimal gzip): +8. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

schiller-manuel added this pull request to stack #8346 September 11, 2026 23:47

github-actions Bot added the package: router-core label Sep 11, 2026

schiller-manuel mentioned this pull request Sep 12, 2026

perf(router): keep the location cache client-only and slim Link SSR #8390

Merged

5 tasks

Sheraff approved these changes Sep 12, 2026

View reviewed changes

schiller-manuel force-pushed the schiller-manuel-search-middleware-compile-memory branch from 6aec14d to 65b6654 Compare September 12, 2026 21:35

schiller-manuel merged commit 9448caa into main Sep 13, 2026
25 of 26 checks passed

schiller-manuel deleted the schiller-manuel-search-middleware-compile-memory branch September 13, 2026 11:55

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perf(router-core): keep search middleware collection optimized - #8385

perf(router-core): keep search middleware collection optimized#8385
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