Simplify example. Fixes #29.

[jakearchibald]

No description provided.

[ricea]

I don't know... it's certainly more concise, but it's hiding a lot of performance cost. I'm worried about sucking people into a slow pattern. I will try to do some actual measurements and get back to you.

[sindresorhus]

Show both then. With the simple one first.

[jakearchibald]

If the performance is very different, maybe we need some higher level APIs:

function compressArrayBuffer(input) {
  return ReadableStream.from(input)
    .pipeThrough(new CompressionStream('deflate'))
    .arrayBuffer();
}

[ricea]

If the performance is very different, maybe we need some higher level APIs:

function compressArrayBuffer(input) {
  return ReadableStream.from(input)
    .pipeThrough(new CompressionStream('deflate'))
    .arrayBuffer();
}

Yes, this is a combination of whatwg/streams#1018 and whatwg/streams#1019.

[ricea]

For compressing 50KB, the version using Blob is over 10 times slower in Chrome 80.0.3987.106:

Compressing 52101 bytes of data 10000 times with compressArrayBufferLong
compressArrayBufferLong: 810.84423828125ms
Compressing 52101 bytes of data 10000 times with compressArrayBufferShort
compressArrayBufferShort: 10981.843017578125ms

Could you retain the existing implementation under the new implementation, marked "(verbose but high-performance version)" or similar?

[jakearchibald]

Whoa, any idea where the overhead comes from? The conversion to blob, or to response?

[jakearchibald]

Makes me wonder if https:/wicg/compression/blob/master/explainer.md#gzip-decompress-a-blob-to-a-blob is similarly slow, and makes even more of a case for the high-level methods.

[ricea]

Whoa, any idea where the overhead comes from? The conversion to blob, or to response?

Blob, because it involves the browser process. If you use the Response constructor to convert-to-stream instead, it's only twice as slow.

[ricea]

Makes me wonder if https:/wicg/compression/blob/master/explainer.md#gzip-decompress-a-blob-to-a-blob is similarly slow, and makes even more of a case for the high-level methods.

There's an implicit assumption in this example that you're using a Blob because your data is huge. Maybe we should add an explicit note that this will perform poorly for "small" data.

[jakearchibald]

Interesting! I've changed the PR to use Response rather than Blob.

[ricea]

Thanks. I'd still like to add some guidance in how to do it performantly, but I can do that in a follow-up change.

[jakearchibald]

Thanks for looking into the performance characteristics! I learned a lot.

[jimmywarting]

Hi 👋
I'm just curious whats make new blob([x]).stream() slower than new response(x).body 😕

[ricea]

Hi
I'm just curious whats make new blob([x]).stream() slower than new response(x).body

See https://bugs.chromium.org/p/chromium/issues/detail?id=1053486#c1 for some background.