msgba-web/js-src/endian.ts

"use strict";

let littleEndian = true; (()=>{ let buf = new ArrayBuffer(4); let buf8 = new
Uint8ClampedArray(buf); let data = new Uint32Array(buf); data[0] = 0xdeadbeef;
if(buf8[0] === 0xde){ littleEndian = false; } })()

export default class Endian {
    static isLittleEndian() {
        return littleEndian;
    }

    static byteArrayToU32BigEndian(inputArray: Uint8Array) {
        if (Endian.isLittleEndian()) {
            inputArray = inputArray.reverse();
        }
        const buffer = inputArray.buffer;
        const outputU32Array = new Uint32Array(buffer);
        return outputU32Array[0];
    }

    static byteArrayToU64BigEndian(inputArray: Uint8Array) {
        if (Endian.isLittleEndian()) {
            inputArray = inputArray.reverse();
        }
        const buffer = inputArray.buffer;
        const outputU64Array = new BigUint64Array(buffer);
        return outputU64Array[0];
    }

    static u64ToByteArrayBigEndian(inputNumber: bigint) {
        const buffer = new ArrayBuffer(8);
        const buffer8 = new Uint8Array(buffer);    
        const buffer64 = new BigUint64Array(buffer);    
        buffer64[0] = inputNumber;
        if (Endian.isLittleEndian()) {
            buffer8.reverse();
        }
        return buffer8;
    }

    static u32ToByteArrayBigEndian(inputNumber: number) {
        const buffer = new ArrayBuffer(4);
        const buffer8 = new Uint8Array(buffer);    
        const buffer32 = new Uint32Array(buffer);    
        buffer32[0] = inputNumber;
        if (Endian.isLittleEndian()) {
            buffer8.reverse();
        }
        return buffer8;
    }
}