Forked from https://gist.github.com/1020396 which was inspired by: https://gist.github.com/999166
This requires Uint8Array (ArrayBuffer) support.
Created
November 4, 2011 07:41
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base64 decoder for typed arrays
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| function( | |
| d, // base64 data (in IE7 or older, use .split('') to get this working | |
| b, // replacement map ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/") | |
| h, // typed array subarray method (.subarray || .subset || .slice) | |
| g, // result buffer | |
| c, // character and - ascii value buffer | |
| u, // bit storage | |
| r, // result byte counter | |
| q, // bit counter | |
| x // char counter | |
| ){ | |
| // buffer and character map, not assuming well-formed input. | |
| g=new Uint8Array(d.length); | |
| h=g.subarray||g.subset||g.slice; | |
| b="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; | |
| for ( | |
| // initialize result and counters | |
| r = 0, q = x = ''; | |
| // get next character | |
| c = d[x++]; | |
| // character found in table? initialize bit storage and add its ascii value; | |
| ~c && (u = q%4 ? u*64+c : c, | |
| // and if not first of each 4 characters, convert the first 8bits to one ascii character | |
| q++ % 4) ? r += String.fromCharCode(255&u>>(-2*q&6)) : 0 | |
| ) | |
| // try to find character in table (0-63, not found => -1) | |
| c = b.indexOf(c); | |
| // return result | |
| return r | |
| } |
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| function(d,b,h,g,c,u,r,q,x){g=new Uint8Array(d.length);h=g.subarray||g.subset||g.slice;b="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";for(r=0,q=x='';c=d[x++];~c&&(u=q%4?u*64+c:c,q++%4)?g[r++]=(255&u>>(-2*q&6)):0)c=b.indexOf(c);return h.call(g,0,r)}; |
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| Copyright* (C) 2011 Charles Pritchard <[email protected]> | |
| Licensed under the Creative Commons Zero License. | |
| http://creativecommons.org/publicdomain/zero/1.0/ | |
| I, Charles Pritchard, hereby release this work into the public domain. |
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| { | |
| "name": "Base64DecoderTypedArray", | |
| "description": "Base64 decoder producing a Typed Array", | |
| "keywords": [ | |
| "base64", | |
| "decode", | |
| "padding", | |
| "rfc2045" | |
| ] | |
| } |
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| <!DOCTYPE html> | |
| <title>Base64 decoder to Typed Array</title> | |
| <script type="text/javascript"> | |
| (function(){ | |
| var f = function(d,b,h,g,c,u,r,q,x){g=new Uint8Array(d.length);h=g.subarray||g.subset||g.slice;b="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";for(r=0,q=x='';c=d[x++];~c&&(u=q%4?u*64+c:c,q++%4)?g[r++]=(255&u>>(-2*q&6)):0)c=b.indexOf(c);return h.call(g,0,r)}; | |
| , test = { | |
| "Zg==" : "f" | |
| ,"Zm8=" : "fo" | |
| ,"Zm9v" : "foo" | |
| ,"Zm9vYg==" : "foob" | |
| ,"Zm9vYmE=" : "fooba" | |
| ,"Zm9vYmFy" : "foobar" | |
| ,"MTQwYnl0ZX\n MgcnVsZXMh" : "140bytes rules!" | |
| } | |
| , error = 0; | |
| ; | |
| for( i in test ) { | |
| var r = f(i); | |
| if( r != test[i] ) { | |
| error++; | |
| document.writeln( 'Expected "'+test[i]+'" for "'+i+'" but got "'+ r + ""<br>" ); | |
| } | |
| } | |
| if( error > 0) { | |
| document.writeln( "<br>"+error+ " tests failed!<br>" ); | |
| } else { | |
| document.writeln( "<br>Everything is fine!<br>" ); | |
| } | |
| })(); | |
| </script> | |
| </body> | |
| </html> |
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