elflib/dist/encoding.js

ELF file reader and writer

/** cross-environment utf-8 decode */
let _decode;
export function decode(array, offset, length) {
    if (_decode) {
        return _decode(array, offset, length);
    }
    else {
        throw new Error('There is no supported utf-8 decoder');
    }
}
if (typeof require !== undefined) {
    let decoder;
    try {
        const { StringDecoder } = require('string_decoder');
        const decoder = new StringDecoder('utf8');
        if (decoder) {
            _decode = (array, offset, length) => {
                return decoder.end(array.subarray(offset, offset + length));
            };
        }
    }
    catch (e) { }
}
if (_decode === undefined && typeof TextDecoder !== 'undefined') {
    const decoder = new TextDecoder();
    _decode = (array, offset, length) => {
        return decoder.decode(array.subarray(offset, offset + length));
    };
}
function toHexSInt(bits, number) {
    if (number < 0)
        number = ((0x100 ** (bits / 8)) - 1) + number + 1;
    return number.toString(16).toUpperCase();
}
export function encode(input, bytesAlign = 0, signed = false, encoding = 'utf-8') {
    if (typeof input === 'string')
        return encodeString(input, encoding);
    if (typeof input === 'number')
        return encodeNumber(Math.floor(input), Math.floor(bytesAlign), signed);
    throw new Error('Unexpected input type "' + typeof input + '".');
}
function encodeString(string, encoding = 'utf-8') {
    return Buffer.from(string, encoding);
}
function encodeNumber(number, bytesAlign = 0, signed = false) {
    if (!signed)
        number = Math.abs(number);
    const tmpstr = signed ? toHexSInt((bytesAlign * 8) || 8, number) : number.toString(16);
    return Buffer.from(tmpstr.padStart(tmpstr.length + Number(tmpstr.length % 2 !== 0), '0').padStart(bytesAlign * 2, '0'), 'hex');
}
export function trimBuffer(buf, offset = 0, length = buf.byteLength) {
    if (buf instanceof ArrayBuffer)
        return buf.slice(offset, offset + length);
    return buf.buffer.slice(buf.byteOffset + offset, buf.byteOffset + offset + length);
}