stream: readable read one buffer at a time by ronag · Pull Request #60441 · nodejs/node · GitHub

Instead of wasting cycles concatenating buffers, just return each
one by one.

Similar (but not exact) old behavior can be achieved by using
`readable.read(readable.readableLength)` instead of
`readable.read()`. In some edge cases it might be necessary
to do a `readable.read(0)` first.

Review requested:

@nodejs/streams

code lgtm

I think some docs changes are needed

Marked as semver-major.

I'm -1 on this unless there is a strong reason for it. Historically, readable.read() has always returned all queued data. If this lands, I think that the easiest workaround for modules affected by the breaking change would be replacing readable.read() with readable.read(readable.readableLength).

I'm -1 on this unless there is a strong reason for it.

The performance overhead is huge. As it stand we should at least add a note to avoid this api for anything performance sensitive.

If this lands, I think that the easiest workaround for modules affected by the breaking change would be replacing readable.read() with readable.read(readable.readableLength).

Good point.

I think some docs changes are needed

What doc changes are you roughly asking for?

Failed to start CI

   ⚠  Commits were pushed since the last approving review:
   ⚠  - stream: readable read one buffer at a time
   ✘  Refusing to run CI on potentially unsafe PR

https://github.com/nodejs/node/actions/runs/20654449594

lgtm

CI: https://ci.nodejs.org/job/node-test-pull-request/70672/

Instead of wasting cycles concatenating buffers, just return each one by one. Similar (but not exact) old behavior can be achieved by using `readable.read(readable.readableLength)` instead of `readable.read()`. In some edge cases it might be necessary to do a `readable.read(0)` first. PR: nodejs#60441

@lpinca Do you need help fixing ws in relation to this PR or can you deal with it yourself?

lgtm

CI: https://ci.nodejs.org/job/node-test-pull-request/70676/

@lpinca Do you need help fixing ws in relation to this PR or can you deal with it yourself?

I've already fixed it in websockets/ws@1998485

CITGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/3663/

CI: https://ci.nodejs.org/job/node-test-pull-request/70687/

lgtm

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- Loading data for nodejs/node/pull/60441
✔  Done loading data for nodejs/node/pull/60441
----------------------------------- PR info ------------------------------------
Title      stream: readable read one buffer at a time (#60441)
Author     Robert Nagy <ronagy@icloud.com> (@ronag)
Branch     ronag:read-no-copy -> nodejs:main
Labels     stream, semver-major, author ready, needs-ci, needs-citgm
Commits    1
 - stream: readable read one buffer at a time
Committers 1
 - Robert Nagy <ronagy@icloud.com>
PR-URL: https://github.com/nodejs/node/pull/60441
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>
------------------------------ Generated metadata ------------------------------
PR-URL: https://github.com/nodejs/node/pull/60441
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>
--------------------------------------------------------------------------------
   ℹ  This PR was created on Mon, 27 Oct 2025 18:44:50 GMT
   ✔  Approvals: 3
   ✔  - Matteo Collina (@mcollina) (TSC): https://github.com/nodejs/node/pull/60441#pullrequestreview-3631894479
   ✔  - Luigi Pinca (@lpinca): https://github.com/nodejs/node/pull/60441#pullrequestreview-3632251382
   ✔  - Gürgün Dayıoğlu (@gurgunday): https://github.com/nodejs/node/pull/60441#pullrequestreview-3635847744
   ✘  semver-major requires at least 2 TSC approvals
   ✔  Last GitHub CI successful
   ℹ  Last Full PR CI on 2026-01-05T21:27:50Z: https://ci.nodejs.org/job/node-test-pull-request/70687/
   ℹ  Last CITGM CI on 2026-01-05T09:54:54Z: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/3663/
- Querying data for job/node-test-pull-request/70687/
✔  Build data downloaded
   ✔  Last Jenkins CI successful
--------------------------------------------------------------------------------
   ✔  Aborted `git node land` session in /home/runner/work/node/node/.ncu

https://github.com/nodejs/node/actions/runs/21187285768

@nodejs/tsc can I get another approval?

Landed in fadb214

ronag requested a review from mcollina October 27, 2025 18:44

nodejs-github-bot added needs-ci PRs that need a full CI run. stream Issues and PRs related to the stream subsystem. labels Oct 27, 2025

MattiasBuelens reviewed Oct 31, 2025

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Comment thread test/parallel/test-stream-readable-infinite-read.js Outdated

mcollina approved these changes Jan 2, 2026

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ronag force-pushed the read-no-copy branch 2 times, most recently from a380c35 to 0798db8 Compare January 2, 2026 08:55

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ronag marked this pull request as ready for review January 2, 2026 08:56

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ronag force-pushed the read-no-copy branch from 0d7fcae to 8cec69c Compare January 2, 2026 08:57

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RafaelGSS mentioned this pull request Apr 27, 2026

2026-05-05, Version 26.0.0 (Current) #62526

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alleria173 mentioned this pull request Jul 28, 2026

Feat/node 26 support gchq/CyberChef#2699

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stream: readable read one buffer at a time by ronag · Pull Request #60441 · nodejs/node · GitHub

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stream: readable read one buffer at a time - #60441

stream: readable read one buffer at a time#60441nodejs-github-bot merged 1 commit intonodejs:mainnodejs/node:mainfrom ronag:read-no-copyronag/node:read-no-copyCopy head branch name to clipboard

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stream: readable read one buffer at a time#60441
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