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dpavlin |
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/* |
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Fast filtering function using pre-sorted list elements |
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Dobrica Pavlinusic, dpavlin@rot13.org 2004-09-06 |
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*/ |
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dpavlin |
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var debug = 1; |
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dpavlin |
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function bfilter_init() { |
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show_status(); |
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} |
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var id_cache = Array(); |
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function element_id(id) { |
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if (id_cache[id]) { |
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return id_cache[id]; |
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} else { |
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var el = document.getElementById(id); |
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if (el) { |
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id_cache[id] = el; |
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return el; |
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} else { |
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alert("can't find element id: "+id); |
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} |
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} |
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} |
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// total number of hits |
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var hits = 0; |
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function show_status(status) { |
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var html; |
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if (hits > 0) { |
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html = "shown "+hits+" entries"; |
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} else { |
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html = "no results"; |
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} |
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if (! status) { |
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html = "Enter "+min_len+" letter"+(min_len == 1 ? '' : 's')+" to filter entries"; |
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status = ""; |
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} |
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var el = element_id("status"); |
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el.innerHTML = html+status+"\n"; |
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} |
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var wait = 0; |
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function results(html,clean) { |
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if (! html) { html = ""; } |
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// results_div.style.cursor = 'wait'; // 'auto' |
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var results_div = element_id("results"); |
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if (clean) { |
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results_div.innerHTML = html+"\n"; |
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} else { |
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results_div.innerHTML += html+"\n"; |
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} |
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} |
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dpavlin |
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// modified binary search to find first element with substring |
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function binarySearch(arr, find) { |
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if (!arr || |
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typeof (arr) != "object" || |
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typeof (find) == "undefined" || !arr.length) { |
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return null; |
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} |
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var low = 0; |
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var high = arr.length - 1; |
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var middlearr = parseInt(arr.length / 2); |
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var lastTry; |
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while (low <= high) { |
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var mid = (low + high) / 2; |
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var aTry = (mid < 1) ? 0 : parseInt(mid); |
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var curr = arr[aTry].substr(0,find.length).toLowerCase(); |
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if (debug) { results("low="+low+" high="+high+" lastTry="+lastTry+" "+aTry+": "+curr+"<br>"); } |
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if (curr < find) { |
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low = aTry + 1; |
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continue; |
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} |
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if (curr > find) { |
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high = aTry - 1; |
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continue; |
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} |
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if (curr == find) { |
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high = aTry - 1; |
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lastTry = aTry; |
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continue; |
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} |
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return aTry; |
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} |
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if (debug) { results("lastTry="+lastTry+"<br>"); } |
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dpavlin |
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dpavlin |
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if (typeof (lastTry) != "undefined") { |
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return lastTry; |
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} else { |
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return null; |
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} |
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} |
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dpavlin |
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function bfilter(document, id, find, arr) { |
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results('',1); |
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hits = 0; |
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if (find.length < min_len) { |
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show_status(); |
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return; |
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} |
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if (debug) { results("filter: '"+find+"'<br>"); } |
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var find_lc = find.toLowerCase(); |
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var part = find_lc.substr(0,min_len); |
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// no part found |
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if (! arr[part]) { |
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show_status(" for <em>"+find+"</em><br>"); |
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return; |
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} |
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// start anim icon |
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//results("<img src=\"pie.gif\"> Please wait, filtering...\n",1); |
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// full part? (optimization) |
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if (find.length == min_len) { |
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var html = ''; |
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for (var i = 0; i < arr[part].length; i++) { |
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dpavlin |
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html += "<li>"+i+": "+arr[part][i]+"</li>\n"; |
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dpavlin |
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hits++; |
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} |
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results(html); |
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} else { |
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dpavlin |
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var from = binarySearch(arr[part], find_lc); |
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dpavlin |
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dpavlin |
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if (from != null) { |
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if (debug) { results("loop "+from+" ... "+arr[part].length)+"<br>\n"; } |
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for(var i = from ; i < arr[part].length ; i++) { |
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if (arr[part][i].substring(0,find.length).toLowerCase() != find_lc) { |
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break; |
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} |
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results(i+": "+arr[part][i]+"<br>\n"); |
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dpavlin |
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hits++; |
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} |
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dpavlin |
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} else { |
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// clean results list |
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// results("",1); |
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dpavlin |
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} |
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} |
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show_status(" for <em>"+find+"</em>"); |
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} |
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