flashmagic.js/lib/UUDecoder.js

NXP LPC Microprocessor Programmer

"use strict";
var Symbol = require('es6-symbol');
var _checksumSym = Symbol();
var UUDecoder = (function () {
    function UUDecoder() {
        this[_checksumSym] = 0;
    }
    Object.defineProperty(UUDecoder.prototype, "checksum", {
        get: function () {
            return this[_checksumSym];
        },
        enumerable: true,
        configurable: true
    });
    UUDecoder.prototype.reset = function () {
        this[_checksumSym] = 0;
    };
    UUDecoder.prototype.decode = function (data) {
        var length = decodeSingle(data.charCodeAt(0));
        var out = new Buffer(length);
        var sum = 0;
        length -= 3;
        var i = 0, j = 1;
        while (i < length) {
            var a = data.charCodeAt(j++);
            var b = data.charCodeAt(j++);
            var c = data.charCodeAt(j++);
            var d = data.charCodeAt(j++);
            var _a = decodeQuad(a, b, c, d), x = _a[0], y = _a[1], z = _a[2];
            sum += x + y + z;
            out[i++] = x;
            out[i++] = y;
            out[i++] = z;
        }
        if (i < out.length) {
            var a = data.charCodeAt(j++);
            var b = data.charCodeAt(j++);
            var c = data.charCodeAt(j++);
            var d = data.charCodeAt(j++);
            var _b = decodeQuad(a, b, c, d), x = _b[0], y = _b[1], z = _b[2];
            sum += x;
            out[i++] = x;
            if (i < out.length) {
                sum += y;
                out[i++] = y;
                if (i < out.length) {
                    sum += z;
                    out[i++] = z;
                }
            }
        }
        this[_checksumSym] += sum;
        return out;
    };
    return UUDecoder;
}());
exports.UUDecoder = UUDecoder;
function decodeSingle(c) {
    return c === 0x60 ? 0 : (c - 32);
}
function decodeQuad(a, b, c, d) {
    a = decodeSingle(a);
    b = decodeSingle(b);
    c = decodeSingle(c);
    d = decodeSingle(d);
    return [((a & 0x3F) << 2) | ((b & 0x30) >>> 4),
        ((b & 0x0F) << 4) | ((c & 0x3C) >>> 2),
        ((c & 0x03) << 6) | (d & 0x3F)];
}