如何从八位字节流的十六进制表示形式实例化ArrayBuffer？

Question

I have binary information coming over a TCP connection (WebSocket). This is traced to the console in an encoded format like so:

53 54 41 52 54 45 44 3a 31 34 32 38 36 30 32 30 38 37 

I presume this is hex encoding of each of the bytes.

The information is actually protocol buffer information. I would like to write a function to decode it using a library I have. The first step is for me to create a buffer object of some kind to encapsulate the binary information for supply to the library.

I do not yet know the precise type expectation of the library, but it expects a binary buffer of some sort.

The protocol buffer decoding library API looks like so:

library.byteBufferToResponse(buffer);

How can I instantiate a "binary buffer" of some kind from a hexadecimal representation of an octet stream?

var octetStream = '34 36 10 04 1a 05 0a 01 30';
var arrayBuffer = new ArrayBuffer(); // How can I initialize this with the binary data?

Answer 1

ArrayBuffer是类型数组的ArrayBuffer ，因此：

var arrayBuffer = new Uint8Array(octetStream).buffer;

Answer 2

You'll want to use a Typed Array to access the buffer. You can directly put that array literal you have into its constructor, it will construct a buffer or the appropriate size.

like body=53 54 41 52 54 45 44 3a 31 34 32 38 36 30 32 30 38 37 37 38 36 which I interpret as hex encoded bytes.

For that, you can use TypedArray.from with a map function:

var msg = "body=53 54 41 52 54 45 44 3a 31 34 32 38 36 30 32 30 38 37 37 38 36";
var arr = Uint8Array.from(msg.slice(5).split(" "), function(byte) {
    return parseInt(byte, 16);
});
var buffer = arr.buffer; // not sure you actually need this