| /* |
| Copyright (c) 2004-2009, The Dojo Foundation All Rights Reserved. |
| Available via Academic Free License >= 2.1 OR the modified BSD license. |
| see: http://dojotoolkit.org/license for details |
| */ |
| |
| |
| if(!dojo._hasResource["dojox.encoding.compression.splay"]){ |
| dojo._hasResource["dojox.encoding.compression.splay"]=true; |
| dojo.provide("dojox.encoding.compression.splay"); |
| dojo.require("dojox.encoding.bits"); |
| dojox.encoding.compression.Splay=function(n){ |
| this.up=new Array(2*n+1); |
| this.left=new Array(n); |
| this.right=new Array(n); |
| this.reset(); |
| }; |
| dojo.extend(dojox.encoding.compression.Splay,{reset:function(){ |
| for(var i=1;i<this.up.length;this.up[i]=Math.floor((i-1)/2),++i){ |
| } |
| for(var i=0;i<this.left.length;this.left[i]=2*i+1,this.right[i]=2*i+2,++i){ |
| } |
| },splay:function(i){ |
| var a=i+this.left.length; |
| do{ |
| var c=this.up[a]; |
| if(c){ |
| var d=this.up[c]; |
| var b=this.left[d]; |
| if(c==b){ |
| b=this.right[d]; |
| this.right[d]=a; |
| }else{ |
| this.left[d]=a; |
| } |
| this[a==this.left[c]?"left":"right"][c]=b; |
| this.up[a]=d; |
| this.up[b]=c; |
| a=d; |
| }else{ |
| a=c; |
| } |
| }while(a); |
| },encode:function(_1,_2){ |
| var s=[],a=_1+this.left.length; |
| do{ |
| s.push(this.right[this.up[a]]==a); |
| a=this.up[a]; |
| }while(a); |
| this.splay(_1); |
| var l=s.length; |
| while(s.length){ |
| _2.putBits(s.pop()?1:0,1); |
| } |
| return l; |
| },decode:function(_3){ |
| var a=0; |
| do{ |
| a=this[_3.getBits(1)?"right":"left"][a]; |
| }while(a<this.left.length); |
| a-=this.left.length; |
| this.splay(a); |
| return a; |
| }}); |
| } |