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-rw-r--r--includes/js/dojox/encoding/compression/lzw.js91
1 files changed, 91 insertions, 0 deletions
diff --git a/includes/js/dojox/encoding/compression/lzw.js b/includes/js/dojox/encoding/compression/lzw.js
new file mode 100644
index 0000000..5e0cca7
--- /dev/null
+++ b/includes/js/dojox/encoding/compression/lzw.js
@@ -0,0 +1,91 @@
+if(!dojo._hasResource["dojox.encoding.compression.lzw"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
+dojo._hasResource["dojox.encoding.compression.lzw"] = true;
+dojo.provide("dojox.encoding.compression.lzw");
+dojo.require("dojox.encoding.bits");
+
+(function(){
+ var _bits = function(x){
+ var w = 1;
+ for(var v = 2; x >= v; v <<= 1, ++w);
+ return w;
+ };
+
+ dojox.encoding.compression.lzw.Encoder = function(n){
+ this.size = n;
+ this.init();
+ };
+
+ dojo.extend(dojox.encoding.compression.lzw.Encoder, {
+ init: function(){
+ this.dict = {};
+ for(var i = 0; i < this.size; ++i){
+ this.dict[String.fromCharCode(i)] = i;
+ }
+ this.width = _bits(this.code = this.size);
+ this.p = "";
+ },
+ encode: function(value, stream){
+ var c = String.fromCharCode(value), p = this.p + c, r = 0;
+ // if already in the dictionary
+ if(p in this.dict){
+ this.p = p;
+ return r;
+ }
+ stream.putBits(this.dict[this.p], this.width);
+ // if we need to increase the code length
+ if((this.code & (this.code + 1)) == 0){
+ stream.putBits(this.code++, r = this.width++);
+ }
+ // add new string
+ this.dict[p] = this.code++;
+ this.p = c;
+ return r + this.width;
+ },
+ flush: function(stream){
+ if(this.p.length == 0){
+ return 0;
+ }
+ stream.putBits(this.dict[this.p], this.width);
+ this.p = "";
+ return this.width;
+ }
+ });
+
+ dojox.encoding.compression.lzw.Decoder = function(n){
+ this.size = n;
+ this.init();
+ };
+
+ dojo.extend(dojox.encoding.compression.lzw.Decoder, {
+ init: function(){
+ this.codes = new Array(this.size);
+ for(var i = 0; i < this.size; ++i){
+ this.codes[i] = String.fromCharCode(i);
+ }
+ this.width = _bits(this.size);
+ this.p = -1;
+ },
+ decode: function(stream){
+ var c = stream.getBits(this.width), v;
+ if(c < this.codes.length){
+ v = this.codes[c];
+ if(this.p >= 0){
+ this.codes.push(this.codes[this.p] + v.substr(0, 1));
+ }
+ }else{
+ if((c & (c + 1)) == 0){
+ this.codes.push("");
+ ++this.width;
+ return "";
+ }
+ var x = this.codes[this.p];
+ v = x + x.substr(0, 1);
+ this.codes.push(v);
+ }
+ this.p = c;
+ return v;
+ }
+ });
+})();
+
+}