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perf(executor): reduce retained storage for small list results - #8617
Retained-memory revalidation:CodeRabbit identified an input-lifetime gap in the diagnostic. Corrected runs hold both input and output through the final heap read, with finally cleanup and WeakRef survival/release controls. Historical master/list medians remain 96.682 → 36.678 MB; current master/list medians are 96.679 → 36.682 MB, with matching output hashes. These are decimal MB; historical and current baselines are separate. The previously rounded retained-byte claims remain supported.
The benchmark-only correction is pushed as e4a279a; all exact-head checks pass, including all four Node/GraphQL test jobs, leak checks, benchmarks and automated review. The original review thread has the corrected methodology and validation.
Responses containing many small lists retain push-grown backing stores that are much larger than their contents. Compacting the executor-owned completed output reduces that retained storage without reading input array lengths, changing iterator consumption, or bypassing scalar serialization.
Only completed synchronous non-streaming lists of 1–8 items are copied; promise and active stream paths retain their existing handling. Proxied arrays with custom iterators, changing input lengths, sparse/frozen inputs and error indexes are covered by characterization tests. The original 1024 cutoff has been tightened after review: exploratory Node 24 / Linux ARM64 runs found approximately 37% retained-output savings at width 8, but only 4% at width 16, with a higher post-execution heap checkpoint there. The cutoff intentionally avoids copying medium-sized lists; this is a runtime-dependent tradeoff, not a universal optimum.
Non-breaking performance improvement; patch changeset for @graphql-tools/executor.
How Has This Been Tested?
Repository build and npm run ts:check pass.
Full Jest suite: 113 suites / 1,765 tests pass; one suite and two tests remain skipped by the existing configuration.
Changed-source ESLint and Prettier checks pass.
The reproduction now lives in the existing execution/__benchmarks__/executor.bench.ts suite. It adds timed width 2, 8, 16 and 1000 matrix cases plus a separate optional retained-storage diagnostic. A fresh Vitest storage run for 500,000 two-number lists measured 96.79 MB before / 36.79 MB after above the input-ready heap, approximately 62% less. This measures retained output, not cumulative allocations or peak heap.
CPU, allocation and transient-memory tradeoff
Five alternating fresh-process comparisons of the revised patch against the same built master returned identical serialized hashes. On the 500,000-pair workload, median CPU was 153.95 → 106.03 ms and elapsed 94.55 → 79.80 ms; retained output was 96.68 → 36.68 MB. Process maximum RSS was 313,700 → 276,020 KiB. These are fresh-request observations, not a claim that every compaction is faster.
The existing warm Vitest Execute Synchronous List Field case (1000 strings) was 0.1177 → 0.1218 ms mean; the added width-2 matrix case was 3.734 → 4.119 ms and width-8 was 2.600 → 2.686 ms. These warm cases expose the extra copy cost. The width-16 case, outside the new cutoff, was 2.423 → 2.446 ms. The patch trades CPU/allocation overhead for lower retained storage rather than guaranteeing a throughput improvement.
Separate V8 sampling runs (HeapProfiler.startSampling, 16 KiB interval, including objects collected by minor/major GC; three fresh comparisons) estimated cumulative allocations of 209.19 → 239.59 MB for the pair workload and 94.64 → 112.56 MB for width 8. Allocated bytes increase while retained bytes decrease. The optional diagnostic supports that allocation protocol via BENCH_LIST_ALLOCATIONS=1; profiling timings are not compared to unprofiled timings.
Separately instrumented sync-list boundary/copy checkpoints measured maximum observed heap of 173.27 → 152.75 MB for pairs, and 68.49 → 55.28 MB for width 8. These checkpoints include instrumentation overhead and are not a continuous heap high-water measurement. The uninstrumented process RSS high-water comparison above provides a separate peak check. Width 1000 is not copied; its fresh-process RSS stayed approximately 114,804 → 114,852 KiB. No per-copy allocation larger than eight output slots is intentionally introduced by compaction; concurrency and other engines remain outside these measurements.
Reproduce after building:
npm run test:bench -- executor.bench.ts
BENCH_LIST_STORAGE=1 npm run test:bench -- executor.bench.ts --execArgv=--expose-gc -t 'completed-list retained storage'# Separate sampled allocation diagnostic:
BENCH_LIST_STORAGE=1 BENCH_LIST_ALLOCATIONS=1 npm run test:bench -- executor.bench.ts --execArgv=--expose-gc -t 'completed-list retained storage'
Use BENCH_PACKAGE_ROOT to point the same suite at a separately built baseline checkout, as CI does. Test environment: Node 24.15.0, Linux ARM64, GraphQL 17.0.2. Browser tests used Chromium in the local container; IPv4-first DNS was needed for its localhost test servers.
The original CI leak failures also reproduced on unchanged master. Investigation traced a strong retaining path from Babel's cached template builder through a raw origin Error and V8 call-site receiver to the calling Jest VM; a fresh module exporting only 123 reproduces it. The independent CI fix #8621, included here, uses the existing patch-package postinstall to retain only a formatted origin-stack string. Seven lifecycle/diagnostic tests cover collection, explicit-retention controls, usable builders and custom stack formatting. No detectors, retries, timeouts or existing suppression rules changed. All four Node22/24 × GraphQL16/17 CI jobs pass on the companion; this branch's new exact-head run is assessed separately.
The actual revised mainline source combined with #8618 passes build/typecheck and all 1,771 tests (two existing skips). Five fresh paired comparisons of that combination retain 36.68 MB for the pair workload with matching output hashes; this is separate from the historical 1.x backport and earlier gateway measurements. Both PRs remain independent on master; their shared benchmark declarations need deliberate merge coordination.
The scalar-path and Babel lifecycle fixes have now merged upstream. This branch is refreshed onto master as 9cac1109d3b0df7dddcf3dd074add5ce03991a6f; its current diff contains only the list-specific change. All exact-head checks pass, including all four Node22/24 × GraphQL16/17 jobs and leak checks. Local build/types/lint, lifecycle checks, all 1,771 tests and both benchmark groups pass.
The preallocation follow-up includes measured actual-executor prototypes. The naive length hint adds observable proxy reads. Node-guarded hints and a portable fixed-eight output buffer passed focused probes but regressed retained output and CPU at widths 2/8. The bounded-copy implementation is retained; the experiments are not shipped. Fresh-process measurements include warmup before the full workload and are not cold-start timings.
Compatibility and discussion
Targets active master without changing dependency ranges or Node engines. The maintainer confirmed that older executor majors do not receive maintained backport releases. Supported upstream adoption uses the current executor through Yoga 6 and matching Hive versions. Yoga 5's executor 1.x range does not receive this mainline change.
The older 1.5.7 source reference is unofficial and preserves the initial proposal, not these subsequent review revisions. It is not a released package, supported maintenance line or recommendation for production replacement. Do not force executor 4.x underneath Yoga 5.
Checklist
Followed the repository contribution/style guidance and opened the related issue first.
Performed a self-review and documented the allocation/ownership rationale.
Added tests and a generic reproduction; no new source lint warnings.
Existing and new tests, typecheck and build pass locally.
No dependent package/API changes are required for this mainline patch.
Developed and validated with Codex (GPT-6.1); performance evidence comes from the included executable reproduction.
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📝 Summary
Summary by CodeRabbit
Performance
Reduced memory retained for some small, synchronous list results when incremental delivery is not used. Results preserve their values and behavior, including input-length access, iteration, scalar handling, and error handling. Empty lists, larger lists, and streamed results continue to use their existing behavior.
The executor now copies synchronous, non-streamed completed lists when they contain 1–8 items. Added tests cover list iteration and completion behavior. Benchmarks measure synchronous matrix execution and provide an opt-in retained-storage diagnostic.
Changes: Completed-list storage
Layer / File(s)
Summary
List completion and validation packages/executor/src/execution/execute.ts, packages/executor/src/execution/__tests__/list-result-storage-test.ts, .changeset/compact-completed-list-storage.md
completeListValue copies synchronous, non-streamed results with 1–8 items. Tests cover iterator behavior, array mutation, sparse and frozen arrays, asynchronous item errors, and scalar serialization. The changeset describes the storage change.
Matrix benchmarks and storage diagnostics packages/executor/src/execution/__benchmarks__/executor.bench.ts
Adds synchronous matrix benchmarks at four widths and an opt-in diagnostic that reports heap, RSS, and serialized result measurements.
ardatan/graphql-tools#8618: Changes the same list-completion path and adds executor benchmarks. The PR descriptions state that the changes require sequential landing and coordination.
ardatan/graphql-tools#8621: Adds the Babel template patch and lifecycle test tooling also included in this PR.
Suggested reviewers:ardatan
Merge Risk: Minimal · up to e4a27
The retained-storage diagnostic now keeps its inputs alive through measurement. No issue identified in this review prevents merging after normal checks.
Pre-merge checks: 4
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Title check
The title clearly and concisely describes the main change: reducing retained storage for small executor list results.
Linked Issues check
Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check
Check skipped because no linked issues were found for this pull request.
Description check
The pull request description clearly explains the small-list storage optimization, implementation scope, tests, benchmarks, compatibility, and validation results. It is directly related to the changes…
Full details: Description check
Explanation
The pull request description clearly explains the small-list storage optimization, implementation scope, tests, benchmarks, compatibility, and validation results. It is directly related to the changeset.
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A rabbit counts lists, one through eight, Then tucks small copies in their place. It tests each yield and scalar too, And measures heaps in matrices new. “The list is done,” it hops away, With benchmarks set for another day.
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Thanks for the write-up and the storage reproduction. Compacting push-grown backing stores for many tiny lists is a real retained-heap issue; the approach (copy only executor-owned completed output, avoid reading input length, leave promise / stream paths alone) is understandable.
A few concerns / questions before merge:
CPU tradeoff: every sync non-stream list with length <= 1024 pays an extra allocate + element copy. That helps retained memory for long-lived dense results, but for short-lived execute-then-serialize responses the capacity waste is often collected anyway while the copy cost remains. Do you have numbers for CPU / elapsed on the compacting path itself (not only retained bytes), especially versus today’s Vitest Execute Synchronous List Field case?
Threshold: why 1024? For mid-size lists the copy is more expensive and the relative capacity waste is smaller. Would a tighter bound (e.g. only very small lists) keep most of the memory win with less CPU risk? Or is there a measurement that supports 1024?
Peak memory: the compact step briefly keeps both the push-grown array and the packed copy alive. Negligible for tiny lists, but worth confirming it does not show up on the mid-size end of the threshold.
Benchmarks: please move the reproduction into the existing Vitest suite (packages/executor/src/execution/__benchmarks__/executor.bench.ts / npm run test:bench) instead of list-storage.mjs, including a case that stresses many small lists (and ideally exposes the CPU side of this tradeoff) so CI’s “Vitest benches vs master” check covers it.
Also note this and #8618 both touch completeListValue; we should land them sequentially and resolve the overlap deliberately.
Happy to re-review after the bench move and any threshold / measurement follow-up.
Cutoff: 1024 → 8 completed items. Exploratory runs found about 37% retained-output savings at width 8, versus 4% at width 16 with a higher post-execution heap checkpoint. Compaction still reads only executor-owned output; promise/stream handling stays intact.
Benchmarks moved into the shared Vitest suite. Added matrix widths 2/8/16/1000 and separate retention/allocation diagnostics alongside the existing 1000-string case.
Measured tradeoff
Less retained memory, more cumulative allocation, and slower warmed cases. Fresh-request timings improved in this workload; CPU improvement is not universal.
Measurement
Master
Revised
Retained output, 500,000 pairs
96.68 MB
36.68 MB
Sampled cumulative allocation, same workload
209.19 MB
239.59 MB
Fresh-process CPU, same workload
153.95 ms
106.03 ms
Fresh-process elapsed, same workload
94.55 ms
79.80 ms
Warm Vitest width-2 matrix, mean
3.734 ms
4.119 ms
Warm Vitest 1000-string list, mean
0.1177 ms
0.1218 ms
Runtime, peak-memory checks and reproduction
Node 24.15.0 / Linux ARM64 / GraphQL 17.0.2. Fresh timings/retention use five alternating paired processes against built master, with matching serialized hashes. Warm Vitest runs are a separate comparison. Allocation sampling uses a separate run with a 16 KiB interval and includes objects collected by minor/major GC; its timings are not mixed into unprofiled results.
Unprofiled process RSS high water: 313,700 → 276,020 KiB for pairs.
Separately instrumented boundary/copy heap checkpoints: 173.27 → 152.75 MB for pairs. These include instrumentation overhead and are not continuous heap high water.
Retained bytes, sampled cumulative allocations and peak measurements describe different quantities.
After building, run the shared timing suite and the separate diagnostics:
npm run test:bench -- executor.bench.ts
BENCH_LIST_STORAGE=1 npm run test:bench -- executor.bench.ts --execArgv=--expose-gc -t 'completed-list retained storage'
BENCH_LIST_STORAGE=1 BENCH_LIST_ALLOCATIONS=1 npm run test:bench -- executor.bench.ts --execArgv=--expose-gc -t 'completed-list retained storage'
BENCH_PACKAGE_ROOT selects a separately built baseline checkout. The PR description contains the wider threshold and peak-memory comparisons.
Validation and CI
Local: build, types, source lint and benchmark typecheck pass; 1,765 tests pass, two existing skips.
Combined revised mainline with perf(executor): allocate scalar list paths only when needed #8618: build/types, 1,771 tests and the combined Vitest suite pass, with matching output hashes in five fresh paired comparisons. Historical backport/gateway measurements are not attributed to this combination.
The shared CI failure now has a separate fix:#8621. Babel cached a template builder retaining a raw origin Error and its V8 call-site receivers, including a calling Jest VM. The existing patch-package workflow now retains a formatted stack string instead. Seven lifecycle/error-diagnostic tests cover collection, explicit retention, usable builders and custom stack formatters.
The companion's four Node 22/24 × GraphQL 16/17 CI jobs pass, with both existing leak detectors intact. The same isolated fix is included here in e2d6046, following a fresh successful build and 1,765 passing tests. It changes development tooling only.
All exact-head checks pass on e2d6046: run 40588395273 passes all four Node 22/24 × GraphQL 16/17 test jobs, including leak checks. Types/lint, Bun, CodeQL, analysis, benchmark comparison and automated review pass too. The maintainer's earlier review remains pending re-review.
Leak failures: base comparison and limits
The original Node 22 / GraphQL 17 job passed ordinary unit tests but failed leak detection. In a local Node 22.23.3 / GraphQL 17 comparison, unchanged base and revised list head both failed use-custom-loader.spec.ts on repeated full runs. Initial runs differed: base passed, while head flagged the SDL-parser suite.
The same custom-loader signature also appears on unchanged master CI. The minimal reproduction requires only a fresh module exporting 123; heap analysis traced the retained VM to Babel's origin Error. See #8619 and babel/babel#18436. No leak checks, retries, timeouts or suppression rules were weakened. One additional local Node24/GraphQL17 full run flagged error-handling.test.ts; three focused runs and its exact 52-suite prefix passed, as did all three PRs' exact-head CI matrices. That local failure remains recorded but unreproduced, with no identified retaining root or speculative fix.
Next
Please re-review the cutoff and measured tradeoff. This PR remains independent on master; sequential landing needs deliberate resolution of the shared benchmark/function edits, with no stack dependency introduced.
The patch moves stack capture, formatting, splitting, and joining from the error path to extendedTrace creation. This work occurs even when fn(arg) succeeds. Measure representative Babel transforms before and after the patch to determine whether it materially affects supported build workloads.
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Review comment at @patches/@babel+template+8.0.0.patch around lines 11 - 14:
Measure representative Babel transforms with and without the eager stack capture
and formatting in extendedTrace creation, including successful fn(arg) calls. If
the cost materially affects supported build workloads, defer stack capture and
formatting until the error path while preserving diagnostic behavior.
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Review comments at @patches/@babel+template+8.0.0.patch:
- Around line 11-14: Measure representative Babel transforms with and without
the eager stack capture and formatting in extendedTrace creation, including
successful fn(arg) calls. If the cost materially affects supported build
workloads, defer stack capture and formatting until the error path while
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Thanks for tightening the cutoff to 8 and for the warm/fresh measurements. That answers the threshold question clearly.
One follow-up on the warm regress: it looks like it comes from the end-of-list allocate + copy. For plain dense arrays, would a safe pre-size path (allocate exact length up front, fill by index, without reading length on proxies / custom iterators) avoid that second copy on the common path?
Retained-memory measurement revalidated:CodeRabbit identified a missing input-lifetime guarantee in the GC diagnostic and private harness. Corrected runs hold input/output through the final heap read with finally cleanup and WeakRef controls. Width-2 retained values reproduce the rounded figures below: copy 36.620 MB, hinted output 52.620 MB, fixed-eight 77.723 MB, with matching output hashes. The lifetime gap is fixed; it did not change this measured conclusion.
I tested that direction against the refreshed branch. The tested preallocation prototypes did not improve CPU or retained output on the target small-list workload.
Safety
Array.isArray also accepts array proxies. Prototype, descriptor and frozen-state checks can themselves invoke proxy traps. The naive length-hint prototype failed the existing proxy/custom-iterator contract by adding a length read; a default array iterator also observed extra reads. Getters and scalar serialization can grow or shrink input during iteration, so a hint cannot become an iteration bound.
I tested a Node util.types.isProxy-guarded hint as a diagnostic, preserving iteration and trimming output to its completed count. It passed the focused behavior probes, but adds a Node-specific dependency to otherwise runtime-neutral executor code. I also tested a portable fixed-eight-slot output buffer using indexed writes and final trimming, without input inspection or an end-copy; its focused probes passed too.
Actual executor comparison
Node 24.15.0 / Linux ARM64 / GraphQL 17.0.2; five alternating fresh-process comparisons per variant and width, copied from the same built executor with recorded source hashes. All timed dense outputs had matching serialized hashes. For 500,000 two-Float lists:
Prototype
Retained output
Fresh CPU
Warm elapsed per 20k-value matrix execution
Current copy, cutoff 8
36.62 MB
106.91 ms
0.931 ms
Node proxy-guarded length hint
52.62 MB
132.12 ms
1.148 ms
Fixed-eight output buffer
77.72 MB
157.01 ms
1.245 ms
Width 8 also regressed in retained output and CPU for both alternatives. Widths 16/1000 had mixed results; that does not offset the regression on the intended tiny-list workload. These are prototype observations, not proof that every possible preallocation implementation loses. The prototypes also change output writes/array representation; the measurements do not isolate the cause to a single operation. Warm measurements use 20 warmups followed by 20 measured executions per child and are separate from the earlier Vitest protocol.
Integration and separate tooling-cost follow-up
The branch is refreshed onto master, retaining the merged scalar completion and Babel lifecycle fixes; its diff now contains only the list change. Local build/types/lint, 1,771 tests, lifecycle checks and both shared benchmark groups pass. All checks on refreshed head 9cac110 now pass, including the four Node22/24 × GraphQL16/17 test jobs, leak checks, benchmarks and automated review.
For the automated review's Babel eager-formatting question: eight alternating pairs on Node22/24 found a real extra 2.18–3.32 microseconds elapsed per newly created successful template builder, but no consistent total-transform slowdown in the tested repository configuration. Warm transforms reused cached builders, limiting that result. The measured cost and limitations are recorded in the upstream issue follow-up; restoring raw Error retention would restore the diagnosed leak.
Prepared and measured with Codex; the preallocation prototypes remain experiments and are not shipped in this PR.
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Actionable comments posted: 1
🪄 Fix comments: Fix CodeRabbit comments on this PR
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Inline comments:
Review comments at
@packages/executor/src/execution/__benchmarks__/executor.bench.ts:
- Line 107: Keep rootValue reachable through the final heap measurement in the
executor benchmark so the input matrix is included in retainedOutputBytes;
release it only after that measurement.
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@ardatan anything you need from me to make this merge ready?
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Description
Retained-memory revalidation: CodeRabbit identified an input-lifetime gap in the diagnostic. Corrected runs hold both input and output through the final heap read, with
finallycleanup and WeakRef survival/release controls. Historical master/list medians remain 96.682 → 36.678 MB; current master/list medians are 96.679 → 36.682 MB, with matching output hashes. These are decimal MB; historical and current baselines are separate. The previously rounded retained-byte claims remain supported.The benchmark-only correction is pushed as
e4a279a; all exact-head checks pass, including all four Node/GraphQL test jobs, leak checks, benchmarks and automated review. The original review thread has the corrected methodology and validation.Responses containing many small lists retain push-grown backing stores that are much larger than their contents. Compacting the executor-owned completed output reduces that retained storage without reading input array lengths, changing iterator consumption, or bypassing scalar serialization.
Only completed synchronous non-streaming lists of 1–8 items are copied; promise and active stream paths retain their existing handling. Proxied arrays with custom iterators, changing input lengths, sparse/frozen inputs and error indexes are covered by characterization tests. The original 1024 cutoff has been tightened after review: exploratory Node 24 / Linux ARM64 runs found approximately 37% retained-output savings at width 8, but only 4% at width 16, with a higher post-execution heap checkpoint there. The cutoff intentionally avoids copying medium-sized lists; this is a runtime-dependent tradeoff, not a universal optimum.
Related #8616.
Type of change
@graphql-tools/executor.How Has This Been Tested?
npm run ts:checkpass.execution/__benchmarks__/executor.bench.tssuite. It adds timed width 2, 8, 16 and 1000 matrix cases plus a separate optional retained-storage diagnostic. A fresh Vitest storage run for 500,000 two-number lists measured 96.79 MB before / 36.79 MB after above the input-ready heap, approximately 62% less. This measures retained output, not cumulative allocations or peak heap.CPU, allocation and transient-memory tradeoff
Five alternating fresh-process comparisons of the revised patch against the same built master returned identical serialized hashes. On the 500,000-pair workload, median CPU was 153.95 → 106.03 ms and elapsed 94.55 → 79.80 ms; retained output was 96.68 → 36.68 MB. Process maximum RSS was 313,700 → 276,020 KiB. These are fresh-request observations, not a claim that every compaction is faster.
The existing warm Vitest
Execute Synchronous List Fieldcase (1000 strings) was 0.1177 → 0.1218 ms mean; the added width-2 matrix case was 3.734 → 4.119 ms and width-8 was 2.600 → 2.686 ms. These warm cases expose the extra copy cost. The width-16 case, outside the new cutoff, was 2.423 → 2.446 ms. The patch trades CPU/allocation overhead for lower retained storage rather than guaranteeing a throughput improvement.Separate V8 sampling runs (
HeapProfiler.startSampling, 16 KiB interval, including objects collected by minor/major GC; three fresh comparisons) estimated cumulative allocations of 209.19 → 239.59 MB for the pair workload and 94.64 → 112.56 MB for width 8. Allocated bytes increase while retained bytes decrease. The optional diagnostic supports that allocation protocol viaBENCH_LIST_ALLOCATIONS=1; profiling timings are not compared to unprofiled timings.Separately instrumented sync-list boundary/copy checkpoints measured maximum observed heap of 173.27 → 152.75 MB for pairs, and 68.49 → 55.28 MB for width 8. These checkpoints include instrumentation overhead and are not a continuous heap high-water measurement. The uninstrumented process RSS high-water comparison above provides a separate peak check. Width 1000 is not copied; its fresh-process RSS stayed approximately 114,804 → 114,852 KiB. No per-copy allocation larger than eight output slots is intentionally introduced by compaction; concurrency and other engines remain outside these measurements.
Reproduce after building:
Use
BENCH_PACKAGE_ROOTto point the same suite at a separately built baseline checkout, as CI does. Test environment: Node 24.15.0, Linux ARM64, GraphQL 17.0.2. Browser tests used Chromium in the local container; IPv4-first DNS was needed for its localhost test servers.The original CI leak failures also reproduced on unchanged master. Investigation traced a strong retaining path from Babel's cached template builder through a raw origin Error and V8 call-site receiver to the calling Jest VM; a fresh module exporting only
123reproduces it. The independent CI fix #8621, included here, uses the existingpatch-packagepostinstall to retain only a formatted origin-stack string. Seven lifecycle/diagnostic tests cover collection, explicit-retention controls, usable builders and custom stack formatting. No detectors, retries, timeouts or existing suppression rules changed. All four Node22/24 × GraphQL16/17 CI jobs pass on the companion; this branch's new exact-head run is assessed separately.The actual revised mainline source combined with #8618 passes build/typecheck and all 1,771 tests (two existing skips). Five fresh paired comparisons of that combination retain 36.68 MB for the pair workload with matching output hashes; this is separate from the historical 1.x backport and earlier gateway measurements. Both PRs remain independent on master; their shared benchmark declarations need deliberate merge coordination.
The scalar-path and Babel lifecycle fixes have now merged upstream. This branch is refreshed onto master as
9cac1109d3b0df7dddcf3dd074add5ce03991a6f; its current diff contains only the list-specific change. All exact-head checks pass, including all four Node22/24 × GraphQL16/17 jobs and leak checks. Local build/types/lint, lifecycle checks, all 1,771 tests and both benchmark groups pass.The preallocation follow-up includes measured actual-executor prototypes. The naive length hint adds observable proxy reads. Node-guarded hints and a portable fixed-eight output buffer passed focused probes but regressed retained output and CPU at widths 2/8. The bounded-copy implementation is retained; the experiments are not shipped. Fresh-process measurements include warmup before the full workload and are not cold-start timings.
Compatibility and discussion
Targets active
masterwithout changing dependency ranges or Node engines. The maintainer confirmed that older executor majors do not receive maintained backport releases. Supported upstream adoption uses the current executor through Yoga 6 and matching Hive versions. Yoga 5's executor 1.x range does not receive this mainline change.The older 1.5.7 source reference is unofficial and preserves the initial proposal, not these subsequent review revisions. It is not a released package, supported maintenance line or recommendation for production replacement. Do not force executor 4.x underneath Yoga 5.
Checklist
Developed and validated with Codex (GPT-6.1); performance evidence comes from the included executable reproduction.