WHATWG Streams

[ronag]

WHATWG Streams are slow, and one of the primary reasons for slow performance with fetch in Node.

[mcollina]

Every stream creates an Error, and creating errors is slow in Node.js because of how we construct them. We also override the base types; I think we should not do that.

[RafaelGSS]

Further info: nodejs/undici#1203 (comment)

Every stream creates a NodeError (even in the happy path) which is slower than the common Error: https://github.com/RafaelGSS/nodejs-bench-operations/blob/main/RESULTS-v18.md#nodejs-error

[anonrig]

I'm going to work on this in the next couple of weeks.

@RafaelGSS Can you share where stream creates a NodeError? I couldn't find the path.
@mcollina Can you share the reference for override the base types?

[anonrig]

I did a small perf change to ReadableStream (nodejs/node#45489)

[ronag]

I did a small perf change to ReadableStream (nodejs/node#45489)

I think you are confusing Readable and ReadableStream. That PR has nothing to do with WHATWG streams as far as I can see.

[metcoder95]

Please correct me if I'm wrong but are @RafaelGSS referring to these errors https://github.com/nodejs/node/blob/1bbd14eac20684a733250629c7896262c0ca4576/lib/internal/webstreams/readablestream.js#L33-L38?

An example from RedeableStream loads this set of errors, which are pre-constructed in https://github.com/nodejs/node/blob/1bbd14eac20684a733250629c7896262c0ca4576/lib/internal/errors.js.

If these are the errors, these should be somehow lazy-loaded or replaced by the common Error constructor?

[RafaelGSS]

No. Actually, per spec when a default writable/readable is released an error should be propagated https://streams.spec.whatwg.org/#writable-stream-default-writer-release, and nowadays this is quite expensive. My initial analysis expands on this.

[RafaelGSS]

Honestly, even changing to common Errors, we won't see much improvement.

[mcollina]

Have you tried with the primoridial Error? https://github.com/nodejs/node/blob/1bbd14eac20684a733250629c7896262c0ca4576/lib/internal/errors.js#L27