I want to convert buffer data to byte array. Here's what I've tried
import * as fs from 'fs';
[...]
event:(data) => {
fs.readFile(data, function(err, data) {
var arrByte= new Uint8Array(data)
var binaryData= new Blob([arrByte])
console.log(binaryData)
}
}
I'm yet to have this work hence my post. I'd very much like to know what I'm doing that's not right.
The Buffer docs are very enlightening:
Prior to the introduction of
TypedArray, the JavaScript language had no mechanism for reading or manipulating streams of binary data. TheBufferclass was introduced as part of the Node.js API to enable interaction with octet streams in TCP streams, file system operations, and other contexts.With
TypedArraynow available, theBufferclass implements theUint8ArrayAPI in a manner that is more optimized and suitable for Node.js.…
Buffer instances are also
Uint8Arrayinstances. However, there are subtle incompatibilities withTypedArray. For example, whileArrayBuffer#slice()creates a copy of the slice, the implementation ofBuffer#slice()creates a view over the existingBufferwithout copying, makingBuffer#slice()far more efficient.It is also possible to create new TypedArray instances from a Buffer with the following caveats:
The
Bufferobject's memory is copied to theTypedArray, not shared.The
Bufferobject's memory is interpreted as an array of distinct elements, and not as a byte array of the target type. That is,new Uint32Array(Buffer.from([1, 2, 3, 4]))creates a 4-elementUint32Arraywith elements[1, 2, 3, 4], not aUint32Arraywith a single element[0x1020304]or[0x4030201].
They go on to mention TypedArray.from, which in node accepts Buffers, so the 'correct' way is:
var arrByte = Uint8Array.from(data)
...however, this shouldn't be necessary at all since a Buffer is a Uint8Array and new UintArray(someBuffer) does work just fine.
There's also no context in your question, but Blob doesn't exist in node, and you shouldn't need it anyway, since Buffer already gives you raw access to binary data and the other fs methods let you read and write files.
Uint8Array [ ]
data)? What is err? I bet you're getting an error and ignoring it. Never skip error checking -- always check err in node callbacks.<Buffer ff d8 ff e0 00 10 4a 46 49 46 00 01 01 01 01 f4 01 f4 00 00 ff db 00 43 00 08 ...> which I want to convert to byte[] and I've also checked if (err) throw err... Guess there's no errUint8Array(55797) [255, 216, 255, 224, 0, 16, 74, 70, 73, 70, 0, 1, 1, 1, 1, 244, ...] when i set arrByte to Uint8Array.from(Buffer.from(data)) Thanks a lot
import * as fs from 'fs';
[...]
event:(data) => {
fs.readFile(data, function(err, data) {
var arrByte= new Uint8Array.from(Buffer.from(data))
var binaryData= new Blob([arrByte])
if (err) throw err;
console.log(binaryData)
}
}
