GZ/nwyj/WebContent/admin/scripts/dojo/dojox/encoding/lzw.js

if (!dojo._hasResource["dojox.encoding.lzw"]) { // _hasResource checks added by
												// build. Do not use
												// _hasResource directly in your
												// code.
	dojo._hasResource["dojox.encoding.lzw"] = true;
	dojo.provide("dojox.encoding.lzw");

	(function() {
		var _bits = function(x) {
			var w = 1;
			for (var v = 2; x >= v; v <<= 1, ++w);
			return w;
		};

		dojox.encoding.lzw.Encoder = function(n) {
			this.size = n;
			this.init();
		};

		dojo.extend(dojox.encoding.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.lzw.Decoder = function(n) {
			this.size = n;
			this.init();
		};

		dojo.extend(dojox.encoding.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;
					}
				});
	})();

}