- Author:
- David Nickerson <nickerso@users.sourceforge.net>
- Date:
- 2009-07-16 02:00:03+12:00
- Desc:
- the starting point for the HH tutorial example
- Permanent Source URI:
- https://models.fieldml.org/workspace/a1/rawfile/f6a8f90307388eb4b040ee3566b84d88b59247f7/dojo-presentation/js/dojo/dojox/encoding/ascii85.js
dojo.provide("dojox.encoding.ascii85");
(function(){
var c = function(input, length, result){
var i, j, n, b = [0, 0, 0, 0, 0];
for(i = 0; i < length; i += 4){
n = ((input[i] * 256 + input[i+1]) * 256 + input[i+2]) * 256 + input[i+3];
if(!n){
result.push("z");
}else{
for(j = 0; j < 5; b[j++] = n % 85 + 33, n = Math.floor(n / 85));
}
result.push(String.fromCharCode(b[4], b[3], b[2], b[1], b[0]));
}
};
dojox.encoding.ascii85.encode = function(input){
// summary: encodes input data in ascii85 string
// input: Array: an array of numbers (0-255) to encode
var result = [], reminder = input.length % 4, length = input.length - reminder;
c(input, length, result);
if(reminder){
var t = input.slice(length);
while(t.length < 4){ t.push(0); }
c(t, 4, result);
var x = result.pop();
if(x == "z"){ x = "!!!!!"; }
result.push(x.substr(0, reminder + 1));
}
return result.join(""); // String
};
dojox.encoding.ascii85.decode = function(input){
// summary: decodes the input string back to array of numbers
// input: String: the input string to decode
var n = input.length, r = [], b = [0, 0, 0, 0, 0], i, j, t, x, y, d;
for(i = 0; i < n; ++i){
if(input.charAt(i) == "z"){
r.push(0, 0, 0, 0);
continue;
}
for(j = 0; j < 5; ++j){ b[j] = input.charCodeAt(i + j) - 33; }
d = n - i;
if(d < 5){
for(j = d; j < 4; b[++j] = 0);
b[d] = 85;
}
t = (((b[0] * 85 + b[1]) * 85 + b[2]) * 85 + b[3]) * 85 + b[4];
x = t & 255;
t >>>= 8;
y = t & 255;
t >>>= 8;
r.push(t >>> 8, t & 255, y, x);
for(j = d; j < 5; ++j, r.pop());
i += 4;
}
return r;
};
})();
