Add WritableStream#write convenience method

[lucacasonato]

Add a WriteableStream.write convenience method to write a single chunk. It locks, writes, then unlocks all in one call.

Towards #1072

• At least two implementers are interested (and none opposed):
  • Deno
  • …
• Tests are written and can be reviewed and commented upon at:
  • …
• Implementation bugs are filed:
  • Chromium: …
  • Gecko: …
  • WebKit: …
  • Deno: …
  • Node.js: …
• MDN issue is filed: …
• The top of this comment includes a clear commit message to use.

(See WHATWG Working Mode: Changes for more details.)

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[jasnell]

The fact that parallel writes wouldn't be allowed (since each write locks the writable) is a bit of a challenge here. I'm not entirely convinced that this is the right thing to add. Can you expand on the motivating use cases a bit more?

[MattiasBuelens]

It might be worth introducing a new abstract op WritableStreamWrite(stream, chunk) for doing a "writer-less write", similar to WritableStreamAbort and WritableStreamClose. We could then rework WritableStreamDefaultWriterWrite to use the same abstract op, similar to how WritableStreamDefaultWriterAbort delegates to WritableStreamAbort.

(We may have to take chunkSize as an extra argument though, since step 5 of WritableStreamDefaultWriterWrite might be difficult to implement otherwise.)

[lucacasonato]

I will do that if I can get implementer interest :)

[lucacasonato]

I'm looking for implementer interest for this change. How are Chromium, Gecko, WebKit, and Cloudflare folks feeling about this? @saschanaz @domenic @jasnell @annevk

[lucacasonato]

@jasnell Yeah see the first thread on this PR. I changed it to do acquire(); write(); release(); waitForWrite(); now.

[annevk]

Nit: please change the commit/PR title to make this not look like it's adding a static method.

[youennf]

Is it the same as https://fs.spec.whatwg.org/#dom-filesystemwritablefilestream-write?

[lucacasonato]

@youennf Yes (but for all WritableStream), not just the FS subclass.

[saschanaz]

I'm interested to have this to replace Bucket FS side equivalent. cc @janvarga

[janvarga]

delegating to @jjjalkanen

[jasnell]

@lucacasonato Cloudflare will implement if this moves forward. I'm not super convinced of the use cases yet as I haven't had anyone ask for this but I certainly don't have a reason not to support it.

[annevk]

If this is happening we should probably remove/refactor FileSystemWritableFileStream#write at the same time.

[domenic]

I'm in favor of this but for Chromium it's @ricea and @nidhijaju who would be doing the work, so please wait for one of them to confirm.