I may be naive in asking this, but what leads someone to building high perf data tools in JS? JS doesn't seem to me like it would be the tool of choice for such things
Performance-wise, I get about half the throughput I had with the same processsing done it rust, which doesn't change anything for my use-case.
However that's not really relevant to the context of the post as I'm using node.js streams which are both saner and fast. I'm guessing that the post is relevant to people using server-side runtimes that only implement web streams.
To your question, I was about to point out Firefox[1], but realized you clarified 'mainstream'[2]...
right now when i need to wrangle bytes, i switch languages to Golang. it’s easy gc language, and all its IO is built around BYOB api:
interface Reader { read(b: Uint8Array): [number, Error?] }
you pass in your own Uint8Array allocation (in go terms, []byte), the reader fills at most the entire thing, and returns (bytes filled, error). it’s a fully pull stream API with one method at its core. now, the api gets to be that simple because it’s always sync, and blocks until the reader can fill data into the buffer or returns an error indicating no data available right now.
go has a TeeReader with no buffering - it too just blocks until it can write to the forked stream.
https://pkg.go.dev/io#TeeReader
we can’t do the same api in JS, because go gets to insert `await` wherever it wants with its coroutine/goroutine runtime. but we can dream of such simplicity combined with zero allocation performance.