Jai_Compression/example.html at master · Debugreality/Jai_Compression · GitHub

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<!--
* Copyright (C) 2013 Jai Shaw. MIT licence below
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN A ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
-->

<html>
<head>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
	<script type="text/javascript" src="libs/jquery-1.7.2.js"></script>
	<script type="text/javascript" src="libs/utilities.js"></script> 	<!-- general functions for debugging -->
	<script type="text/javascript" src="libs/compress.js"></script> 	<!-- basic compression libary -->
</head>
<body>
	<h1>Huffman Compression example </h1>

	<div>
		<textarea style="width:600px;height:300px;" id="comp_input">Input - put text to compress here and press tab to compress it.</textarea>

		<textarea style="width:600px;height:300px;" id="comp_output">compressed text (includes non printable characters!)</textarea>
	</div>

	<div>
		<textarea style="width:1200px;height:300px;" id="uncomp_output">uncompressed from javascript compression string</textarea>
	</div>
	<div id="jaiLog" style="font-family:courier;"></div>

	<script type="text/javascript">
		$(function(){
			$('#comp_input').blur(function(){blur_compress(this);});
		});

		function blur_compress(elementIn)
		{
			document.getElementById('jaiLog').innerHTML = ''; // Clear debug output

			// initial some variables
			var compData = elementIn.value;
			var encodeKey = [];

			var compArray = jaiNs.compress.makeArray(compData); // create frequency array

			// Create tree and get encodeKey
			jaiNs.compress.makeTree(compArray);
			jaiNs.compress.buildBinStrArray(compArray[0],encodeKey);
			encodeKey.sort(function(e1,e2){return(e2[1]-e1[1]);}); // sorting the key by frequency does speed up both compression and inflation

			// Compress your data with the encode key
			for(var e in encodeKey) {jaiNs.util.var_export(encodeKey[e]);}
			jaiNs.util.echo(' ');
			var dataCompressed = jaiNs.compress.compress(compData,encodeKey);
			document.getElementById('comp_output').value = dataCompressed;

			// determine how much compression we achieved
			var beforeCount = compData.length;
			var afterCount = dataCompressed.length;
			var compPercentage = (afterCount/beforeCount) * 100;
			compPercentage = compPercentage.toFixed(1);
			jaiNs.util.echo(' ');
			jaiNs.util.echo('Compression ' + beforeCount.toString()  + '->' + afterCount.toString() + ' ('+compPercentage.toString()+'%)');

			// decompress data for verification
			var origStr = jaiNs.compress.inflate(dataCompressed,encodeKey);
			document.getElementById('uncomp_output').value = origStr;
		}
	</script>

</body>
</html>