base64.js updated to 2.6

From https://github.com/dankogai/js-base64

(cherry picked from commit 7e5c36ed5b7fc67ba919973834e015ce92b5708b)

js/base64.js

@@ -1,128 +1,139 @@
 /*
- * $Id: base64.js,v 1.2 2011/12/27 14:34:49 dankogai Exp dankogai $
+ * $Id: base64.js,v 2.6 2012/08/24 05:23:18 dankogai Exp dankogai $
  *
  *  Licensed under the MIT license.
  *  http://www.opensource.org/licenses/mit-license.php
  *
+ *  References:
+ *    http://en.wikipedia.org/wiki/Base64
  */
 
-(function(global){
-
-if (global.Base64) return;
-
-var b64chars 
+(function(global) {
+'use strict';
+// 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 b64tab = function(bin) {
     var t = {};
     for (var i = 0, l = bin.length; i < l; i++) t[bin.charAt(i)] = i;
     return t;
 }(b64chars);
-
-var sub_toBase64 = function(m){
-    var n = (m.charCodeAt(0) << 16)
-          | (m.charCodeAt(1) <<  8)
-          | (m.charCodeAt(2)      );
-    return b64chars.charAt( n >>> 18)
-         + b64chars.charAt((n >>> 12) & 63)
-         + b64chars.charAt((n >>>  6) & 63)
-         + b64chars.charAt( n         & 63);
+var fromCharCode = String.fromCharCode;
+// encoder stuff
+var cb_utob = function(c) {
+    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));
 };
-
-var toBase64 = function(bin){
-    if (bin.match(/[^\x00-\xFF]/)) throw 'unsupported character found' ;
-    var padlen = 0;
-    while(bin.length % 3) {
-        bin += '\0';
-        padlen++;
-    };
-    var b64 = bin.replace(/[\x00-\xFF]{3}/g, sub_toBase64);
-    if (!padlen) return b64;
-    b64 = b64.substr(0, b64.length - padlen);
-    while(padlen--) b64 += '=';
-    return b64;
+var utob = function(u) {
+    return u.replace(/[^\x00-\x7F]/g, cb_utob);
 };
-
-var btoa = global.btoa || toBase64;
-
-var sub_fromBase64 = function(m){
-        var n = (b64tab[ m.charAt(0) ] << 18)
-            |   (b64tab[ m.charAt(1) ] << 12)
-            |   (b64tab[ m.charAt(2) ] <<  6)
-            |   (b64tab[ m.charAt(3) ]);
-    return String.fromCharCode(  n >> 16 )
-        +  String.fromCharCode( (n >>  8) & 0xff )
-        +  String.fromCharCode(  n        & 0xff );
+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 fromBase64 = function(b64){
-    b64 = b64.replace(/[^A-Za-z0-9\+\/]/g, '');
-    var padlen = 0;
-    while(b64.length % 4){
-        b64 += 'A';
-        padlen++;
-    }
-    var bin = b64.replace(/[A-Za-z0-9\+\/]{4}/g, sub_fromBase64);
-    if (padlen >= 2)
-        bin = bin.substring(0, bin.length - [0,0,2,1][padlen]);
-    return bin;
+var btoa = global.btoa || function(b) {
+    return b.replace(/[\s\S]{1,3}/g, cb_encode);
 };
-
-var atob = global.atob || fromBase64;
-
-var re_char_nonascii = /[^\x00-\x7F]/g;
-
-var sub_char_nonascii = function(m){
-    var n = m.charCodeAt(0);
-    return n < 0x800 ? String.fromCharCode(0xc0 | (n >>>  6))
-                     + String.fromCharCode(0x80 | (n & 0x3f))
-        :              String.fromCharCode(0xe0 | ((n >>> 12) & 0x0f))
-                     + String.fromCharCode(0x80 | ((n >>>  6) & 0x3f))
-                     + String.fromCharCode(0x80 |  (n         & 0x3f))
-        ;
+var _encode = buffer
+    ? function (u) { return (new buffer(u)).toString('base64') } 
+    : function (u) { return btoa(utob(u)) }
+    ;
+var encode = function(u, urisafe) {
+    return !urisafe 
+        ? _encode(u)
+        : _encode(u).replace(/[+\/]/g, function(m0) {
+            return m0 == '+' ? '-' : '_';
+        });
 };
-
-var utob = function(uni){
-    return uni.replace(re_char_nonascii, sub_char_nonascii);
+var encodeURI = function(u) { return encode(u, true) };
+// decoder stuff
+var re_btou = /[\xC0-\xDF][\x80-\xBF]|[\xE0-\xEF][\x80-\xBF]{2}/g;
+var cb_btou = function(ccc) {
+    return fromCharCode(
+        ccc.length < 3 ? ((0x1f & ccc.charCodeAt(0)) << 6)
+                       |  (0x3f & ccc.charCodeAt(1))
+                       : ((0x0f & ccc.charCodeAt(0)) << 12)
+                       | ((0x3f & ccc.charCodeAt(1)) << 6)
+                       |  (0x3f & ccc.charCodeAt(2))
+    );
 };
-
-var re_bytes_nonascii
-    = /[\xC0-\xDF][\x80-\xBF]|[\xE0-\xEF][\x80-\xBF]{2}|[\xF0-\xF7][\x80-\xBF]{3}/g;
-
-var sub_bytes_nonascii = function(m){
-    var c0 = m.charCodeAt(0);
-    var c1 = m.charCodeAt(1);
-    if(c0 < 0xe0){
-        return String.fromCharCode(((c0 & 0x1f) << 6) | (c1 & 0x3f));
-    }else{
-        var c2 = m.charCodeAt(2);
-        return String.fromCharCode(
-            ((c0 & 0x0f) << 12) | ((c1 & 0x3f) <<  6) | (c2 & 0x3f)
-        );
-    }
+var btou = function(b) {
+    return b.replace(re_btou, cb_btou);
 };
-    
-var btou = function(bin){
-    return bin.replace(re_bytes_nonascii, sub_bytes_nonascii);
+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 a.replace(/[\s\S]{1,4}/g, cb_decode);
+};
+var _decode = buffer
+    ? function(a) { return (new buffer(a, 'base64')).toString() }
+    : function(a) { return btou(atob(a)) }
+    ;
+var decode = function(a){
+    return _decode(
+        a.replace(/[-_]/g, function(m0) { return m0 == '-' ? '+' : '/' })
+         .replace(/[^A-Za-z0-9\+\/]/g, '')
+    );
+};
+// export Base64
 global.Base64 = {
-    fromBase64:fromBase64,
-    toBase64:toBase64,
-    atob:atob,
-    btoa:btoa,
-    utob:utob,
-    btou:btou,
-    encode:function(u){ return btoa(utob(u)) },
-    encodeURI:function(u){
-        return btoa(utob(u)).replace(/[+\/]/g, function(m0){
-            return m0 == '+' ? '-' : '_';
-        }).replace(/=+$/, '');
-    },
-    decode:function(a){ 
-        return btou(atob(a.replace(/[-_]/g, function(m0){
-            return m0 == '-' ? '+' : '/';
-        })));
-    }
+    atob: atob,
+    btoa: btoa,
+    fromBase64: decode,
+    toBase64: encode,
+    utob: utob,
+    encode: encode,
+    encodeURI: encodeURI,
+    btou: btou,
+    decode: decode
 };
-
+// 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)
+        }));
+    };
+}
+// that's it!
 })(this);