flashmagic.js/lib/UUEncoder.js

NXP LPC Microprocessor Programmer

"use strict";
var Symbol = require('es6-symbol');
var _checksumSym = Symbol();
var UUEncoder = (function () {
    function UUEncoder() {
        this[_checksumSym] = 0;
    }
    Object.defineProperty(UUEncoder.prototype, "checksum", {
        get: function () {
            return this[_checksumSym];
        },
        enumerable: true,
        configurable: true
    });
    UUEncoder.prototype.reset = function () {
        this[_checksumSym] = 0;
    };
    UUEncoder.prototype.encode = function (data, offset, length) {
        var out = encodeSingle(length);
        var sum = 0;
        var n = ~~(length / 3) * 3;
        var m = n + offset;
        var i = offset;
        while (i < m) {
            var a = data[i++];
            var b = data[i++];
            var c = data[i++];
            out += encodeTriple(a, b, c);
            sum += a + b + c;
        }
        if (n < length) {
            var a = data[i++];
            var b = (n + 1 < length) ? data[i] : 0;
            out += encodeTriple(a, b, 0);
            sum += a + b;
        }
        this[_checksumSym] += sum;
        return out;
    };
    return UUEncoder;
}());
exports.UUEncoder = UUEncoder;
function encodeSingle(b) {
    return String.fromCharCode(b ? (b + 32) : 0x60);
}
function encodeTriple(a, b, c) {
    return encodeSingle((a >>> 2) & 0x3F) +
        encodeSingle(((a << 4) & 0x30) | ((b >>> 4) & 0x0F)) +
        encodeSingle(((b << 2) & 0x3C) | ((c >>> 6) & 0x03)) +
        encodeSingle(c & 0x3F);
}