- /*
- * $Id: base64.js,v 2.15 2014/04/05 12:58:57 dankogai Exp dankogai $
- *
- * Licensed under the MIT license.
- * http://opensource.org/licenses/mit-license
- *
- * References:
- * http://en.wikipedia.org/wiki/Base64
- */
- (function() {
- 'use strict';
- angular.module('base64', []).constant('$base64', (function() {
- // existing version for noConflict()
- var version = "2.1.8";
- // if node.js, we use Buffer
- var buffer;
- if (typeof module !== 'undefined' && module.exports) {
- buffer = require('buffer').Buffer;
- }
- // 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 = 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 = 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, ''));
- };
- return {
- encode: encode,
- decode: decode,
- };
- })());
- })();
- //该片段来自于http://www.codesnippet.cn/detail/2107201513184.html
来源: http://www.codesnippet.cn/detail/2107201513184.html