Version
16.14.0
Platform
Darwin Alans-MacBook-Pro.local 21.1.0 Darwin Kernel Version 21.1.0: Wed Oct 13 17:33:01 PDT 2021; root:xnu-8019.41.5~1/RELEASE_ARM64_T6000 arm64
Subsystem
No response
What steps will reproduce the bug?
import crypto from 'crypto'
import { Blob } from 'buffer'
async function main () {
const bytes = crypto.randomBytes(1024e6)
const blob = new Blob([bytes])
const reader = blob.stream().getReader()
console.time('read')
const result = await reader.read()
console.timeEnd('read')
console.log(result.value.length, 'bytes')
reader.cancel()
}
main()Output:
$ node test.js
read: 203.812ms
65536 bytes
How often does it reproduce? Is there a required condition?
No response
What is the expected behavior?
No response
What do you see instead?
Why does it take 203ms to read 65kb from an in memory buffer?
blob.slice(0, 65536) takes 0.148ms so maybe some copying is happening?
const buf = await blob.arrayBuffer()
const slice = buf.slice(0, 65536)
Takes 105ms, which is still half the time stream.read() takes.
Additional information
No response
Version
16.14.0
Platform
Darwin Alans-MacBook-Pro.local 21.1.0 Darwin Kernel Version 21.1.0: Wed Oct 13 17:33:01 PDT 2021; root:xnu-8019.41.5~1/RELEASE_ARM64_T6000 arm64
Subsystem
No response
What steps will reproduce the bug?
Output:
How often does it reproduce? Is there a required condition?
No response
What is the expected behavior?
No response
What do you see instead?
Why does it take 203ms to read 65kb from an in memory buffer?
blob.slice(0, 65536)takes0.148msso maybe some copying is happening?Takes
105ms, which is still half the timestream.read()takes.Additional information
No response