stream: readable read one buffer at a time #60441

ronag · 2025-10-27T18:44:50Z

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.

nodejs-github-bot · 2025-10-27T18:44:55Z

Review requested:

@nodejs/streams

test/parallel/test-stream-readable-infinite-read.js

mcollina

code lgtm

I think some docs changes are needed

mcollina · 2026-01-02T08:05:20Z

Marked as semver-major.

lpinca · 2026-01-02T08:27:37Z

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).

ronag · 2026-01-02T08:48:08Z

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.

ronag · 2026-01-02T08:51:56Z

I think some docs changes are needed

What doc changes are you roughly asking for?

Instead of wasting cycles concatenating buffers, just return each one by one. Old behavior can be achieved by using `readable.read(readable.readableLength)` instead of `readable.read()`. PR: nodejs#60441

github-actions · 2026-01-02T08:58:57Z

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

nodejs-github-bot · 2026-01-04T17:11:35Z

CI: https://ci.nodejs.org/job/node-test-pull-request/70669/

mcollina

lgtm

nodejs-github-bot · 2026-01-05T08:51:29Z

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

ronag · 2026-01-05T09:27:53Z

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

mcollina

lgtm

nodejs-github-bot · 2026-01-05T09:53:06Z

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

lpinca · 2026-01-05T09:53:46Z

@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

ronag · 2026-01-05T09:54:54Z

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

nodejs-github-bot · 2026-01-05T21:27:50Z

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

mcollina

lgtm

gurgunday

lgtm

nodejs-github-bot · 2026-01-20T21:08:50Z

Commit Queue failed

- 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

mcollina · 2026-01-20T22:07:52Z

@nodejs/tsc can I get another approval?

nodejs-github-bot · 2026-01-21T08:29:42Z

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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stream: readable read one buffer at a time #60441

stream: readable read one buffer at a time #60441

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ronag commented Oct 27, 2025 •

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