base64 javascript

gistfile1.js

(function ($) {
    /**
     * The base64 en/decoder that supports UTF8 characters like Chinese.
     * @namespace
     * @name pb.util.base64
     */
    var base64 = pb.getObject("util.base64");

    var b64chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
    var b64tab = function (bin) {
        var t = {};
        for (var i = 0, l = bin.length; i < l; i++) t[bin.charAt(i)] = i;
        return t;
    }(b64chars);
    var fromCharCode = String.fromCharCode;

    $.extend(base64, /** @lends pb.util.base64 */{
        // encoder stuff
        cb_utob: function (c) {
            if (c.length < 2) {
                var cc = c.charCodeAt(0);
                return cc < 0x80 ? c
                    : cc < 0x800 ? (fromCharCode(0xc0 | (cc >>> 6))
                + fromCharCode(0x80 | (cc & 0x3f)))
                    : (fromCharCode(0xe0 | ((cc >>> 12) & 0x0f))
                + fromCharCode(0x80 | ((cc >>> 6) & 0x3f))
                + fromCharCode(0x80 | ( cc & 0x3f)));
            } else {
                var cc = 0x10000
                    + (c.charCodeAt(0) - 0xD800) * 0x400
                    + (c.charCodeAt(1) - 0xDC00);
                return (fromCharCode(0xf0 | ((cc >>> 18) & 0x07))
                + fromCharCode(0x80 | ((cc >>> 12) & 0x3f))
                + fromCharCode(0x80 | ((cc >>> 6) & 0x3f))
                + fromCharCode(0x80 | ( cc & 0x3f)));
            }
        },
        utob: function (u) {
            return u.replace(/[\uD800-\uDBFF][\uDC00-\uDFFFF]|[^\x00-\x7F]/g, base64.cb_utob);
        },
        cb_encode: function (ccc) {
            var padlen = [0, 2, 1][ccc.length % 3],
                ord = ccc.charCodeAt(0) << 16
                    | ((ccc.length > 1 ? ccc.charCodeAt(1) : 0) << 8)
                    | ((ccc.length > 2 ? ccc.charCodeAt(2) : 0)),
                chars = [
                    b64chars.charAt(ord >>> 18),
                    b64chars.charAt((ord >>> 12) & 63),
                    padlen >= 2 ? '=' : b64chars.charAt((ord >>> 6) & 63),
                    padlen >= 1 ? '=' : b64chars.charAt(ord & 63)
                ];
            return chars.join('');
        },
        btoa: function (b) {
            return b.replace(/[\s\S]{1,3}/g, base64.cb_encode);
        },
        _encode: function (u) {
            return base64.btoa(base64.utob(u))
        },

        encode: function (u, urisafe) {
            return !urisafe
                ? base64._encode(String(u))
                : base64._encode(String(u)).replace(/[+\/]/g, function (m0) {
                return m0 == '+' ? '-' : '_';
            }).replace(/=/g, '');
        },
        encodeURI: function (u) {
            return encode(u, true)
        },
        // decoder stuff
        re_btou: new RegExp([
            '[\xC0-\xDF][\x80-\xBF]',
            '[\xE0-\xEF][\x80-\xBF]{2}',
            '[\xF0-\xF7][\x80-\xBF]{3}'
        ].join('|'), 'g'),
        cb_btou: function (cccc) {
            switch (cccc.length) {
                case 4:
                    var cp = ((0x07 & cccc.charCodeAt(0)) << 18)
                            | ((0x3f & cccc.charCodeAt(1)) << 12)
                            | ((0x3f & cccc.charCodeAt(2)) << 6)
                            | (0x3f & cccc.charCodeAt(3)),
                        offset = cp - 0x10000;
                    return (fromCharCode((offset >>> 10) + 0xD800)
                    + fromCharCode((offset & 0x3FF) + 0xDC00));
                case 3:
                    return fromCharCode(
                        ((0x0f & cccc.charCodeAt(0)) << 12)
                        | ((0x3f & cccc.charCodeAt(1)) << 6)
                        | (0x3f & cccc.charCodeAt(2))
                    );
                default:
                    return fromCharCode(
                        ((0x1f & cccc.charCodeAt(0)) << 6)
                        | (0x3f & cccc.charCodeAt(1))
                    );
            }
        },
        btou: function (b) {
            return b.replace(base64.re_btou, base64.cb_btou);
        },
        cb_decode: function (cccc) {
            var len = cccc.length,
                padlen = len % 4,
                n = (len > 0 ? b64tab[cccc.charAt(0)] << 18 : 0)
                    | (len > 1 ? b64tab[cccc.charAt(1)] << 12 : 0)
                    | (len > 2 ? b64tab[cccc.charAt(2)] << 6 : 0)
                    | (len > 3 ? b64tab[cccc.charAt(3)] : 0),
                chars = [
                    fromCharCode(n >>> 16),
                    fromCharCode((n >>> 8) & 0xff),
                    fromCharCode(n & 0xff)
                ];
            chars.length -= [0, 0, 2, 1][padlen];
            return chars.join('');
        },
        atob: function (a) {
            return a.replace(/[\s\S]{1,4}/g, base64.cb_decode);
        },
        _decode: function (a) {
            return base64.btou(atob(a))
        },
        decode: function (a) {
            return base64._decode(
                String(a).replace(/[-_]/g, function (m0) {
                    return m0 == '-' ? '+' : '/'
                })
                    .replace(/[^A-Za-z0-9\+\/]/g, '')
            );
        }
    });
}