JsonBird/static/js/base64.js

/*
 * $Id: base64.js,v 2.15 2014/04/05 12:58:57 dankogai Exp dankogai $
 *
 *  Licensed under the BSD 3-Clause License.
 *    http://opensource.org/licenses/BSD-3-Clause
 *
 *  References:
 *    http://en.wikipedia.org/wiki/Base64
 */

(function(global) {
    'use strict';
    // existing version for noConflict()
    var _Base64 = global.Base64;
    var version = "2.1.9";
    // if node.js, we use Buffer
    var buffer;
    if (typeof module !== 'undefined' && module.exports) {
        try {
            buffer = require('buffer').Buffer;
        } catch (err) {}
    }
    // constants
    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;
    // encoder stuff
    var 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)));
        }
    };
    var re_utob = /[\uD800-\uDBFF][\uDC00-\uDFFFF]|[^\x00-\x7F]/g;
    var utob = function(u) {
        return u.replace(re_utob, cb_utob);
    };
    var 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('');
    };
    var btoa = global.btoa ? function(b) {
        return global.btoa(b);
    } : function(b) {
        return b.replace(/[\s\S]{1,3}/g, cb_encode);
    };
    var _encode = buffer ? function(u) {
            return (u.constructor === buffer.constructor ? u : new buffer(u))
                .toString('base64')
        } :
        function(u) { return btoa(utob(u)) };
    var encode = function(u, urisafe) {
        return !urisafe ?
            _encode(String(u)) :
            _encode(String(u)).replace(/[+\/]/g, function(m0) {
                return m0 == '+' ? '-' : '_';
            }).replace(/=/g, '');
    };
    var encodeURI = function(u) { return encode(u, true) };
    // decoder stuff
    var re_btou = new RegExp([
        '[\xC0-\xDF][\x80-\xBF]',
        '[\xE0-\xEF][\x80-\xBF]{2}',
        '[\xF0-\xF7][\x80-\xBF]{3}'
    ].join('|'), 'g');
    var 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))
                );
        }
    };
    var btou = function(b) {
        return b.replace(re_btou, cb_btou);
    };
    var 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('');
    };
    var atob = global.atob ? function(a) {
        return global.atob(a);
    } : function(a) {
        return a.replace(/[\s\S]{1,4}/g, cb_decode);
    };
    var _decode = buffer ? function(a) {
            return (a.constructor === buffer.constructor ?
                a : new buffer(a, 'base64')).toString();
        } :
        function(a) { return btou(atob(a)) };
    var decode = function(a) {
        return _decode(
            String(a).replace(/[-_]/g, function(m0) { return m0 == '-' ? '+' : '/' })
            .replace(/[^A-Za-z0-9\+\/]/g, '')
        );
    };
    var noConflict = function() {
        var Base64 = global.Base64;
        global.Base64 = _Base64;
        return Base64;
    };
    // export Base64
    global.Base64 = {
        VERSION: version,
        atob: atob,
        btoa: btoa,
        fromBase64: decode,
        toBase64: encode,
        utob: utob,
        encode: encode,
        encodeURI: encodeURI,
        btou: btou,
        decode: decode,
        noConflict: noConflict
    };
    // if ES5 is available, make Base64.extendString() available
    if (typeof Object.defineProperty === 'function') {
        var noEnum = function(v) {
            return { value: v, enumerable: false, writable: true, configurable: true };
        };
        global.Base64.extendString = function() {
            Object.defineProperty(
                String.prototype, 'fromBase64', noEnum(function() {
                    return decode(this)
                }));
            Object.defineProperty(
                String.prototype, 'toBase64', noEnum(function(urisafe) {
                    return encode(this, urisafe)
                }));
            Object.defineProperty(
                String.prototype, 'toBase64URI', noEnum(function() {
                    return encode(this, true)
                }));
        };
    }
    // that's it!
    if (global['Meteor']) {
        Base64 = global.Base64; // for normal export in Meteor.js
    }
})(this);