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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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Matko Andjelinic, matko.andjelinic@gmail.com 2004-09-09 (contributed OO implementation) |
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*/ |
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|
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top.__bfilter_obj = new Array(); |
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|
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|
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function BFilter(arr) { |
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this.id_cache = Array(); |
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// total number of hits |
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this.hits = 0; |
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|
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// store reference to this object for later (YAK) |
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this.obj_count = top.__bfilter_obj.length; |
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top.__bfilter_obj[this.obj_count] = this; |
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|
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// clear results html |
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this.results_html = null; |
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|
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// show results after 0.2s |
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this.timeout = 200; |
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this.timeout_handle = null; |
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|
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if (! arr) { |
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this.debug("ERROR: can't search empty array"); |
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return; |
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} |
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|
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this.arr = arr; |
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this.debug("index has "+this.arr.length+" parts"); |
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|
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if (! arr.min_len) { |
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alert("ERROR: index structure problem"); |
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return; |
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} else { |
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this.min_len = arr.min_len; |
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} |
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|
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this.debug("index part has "+this.min_len+" parts"); |
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|
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this.show_status(); |
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|
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// show alert for non-existent elements? |
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this.show_alert = 1; |
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|
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} |
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|
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BFilter.prototype.element_id = function (id,no_alert) { |
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if (this.id_cache[id]) { |
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return this.id_cache[id]; |
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} else { |
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var el = self.document.getElementById(id); |
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if (el) { |
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this.id_cache[id] = el; |
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return el; |
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} else { |
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if (! no_alert && this.show_alert) { |
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this.show_alert = confirm("can't find element id: "+id); |
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} else { |
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// don't look it up again |
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this.id_cache[id] = null; |
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} |
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} |
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} |
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return null; |
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} |
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|
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|
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BFilter.prototype.show_status = function (status,no_hits) { |
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var html = ""; |
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if (! no_hits) { |
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if (this.hits > 0) { |
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html = "shown "+this.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 "+this.min_len+" letter"+(this.min_len == 1 ? '' : 's')+" to filter entries"; |
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status = ""; |
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} |
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} |
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|
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var el = this.element_id("status"); |
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el.innerHTML = html+status+"\n"; |
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|
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return true; |
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} |
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|
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// this function is called to clean old results list |
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BFilter.prototype.clear_results = function () { |
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var results_div = this.element_id("results"); |
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results_div.innerHTML = ''; |
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this.results_html = ''; |
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return true; |
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} |
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|
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// this function is called for each result |
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BFilter.prototype.result = function (arr) { |
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this.results_html += '<li><a href="'+arr[1]+'">'+ |
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(this.hits % 2 == 0 ? '<span style="background: #e0e0e0;">' : '') + |
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arr[0] + |
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(this.hits % 2 == 0 ? '</span>' : '') + |
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'</a></li>'; |
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return true; |
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} |
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|
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// this function is called when updating innerHTML with results |
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BFilter.prototype.show_results = function () { |
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var results_div = this.element_id("results"); |
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if (this.results_html) { |
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results_div.innerHTML = '<ul>'+this.results_html+'</ul>'; |
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} |
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return true; |
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} |
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|
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BFilter.prototype.debug = function (html) { |
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|
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//return; |
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|
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// check if debugging is on |
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if (! html) { return 1; } |
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|
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var debug_div = this.element_id("debug",1); |
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if (! debug_div) { return null; } |
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|
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debug_div.innerHTML += html + "<br>\n"; |
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|
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return null; |
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} |
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|
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|
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// modified binary search to find first element with substring |
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BFilter.prototype.binarySearch = function (arr, user_filter) { |
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if (!arr || typeof (user_filter) == "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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this.debug("binarySearch: "+low+"-("+middlearr+")-"+high+" for "+user_filter); |
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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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|
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var curr = arr[aTry][0].substr(0,user_filter.length).toLowerCase(); |
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this.debug(low+"-"+high+", "+aTry+"="+curr+" last="+lastTry); |
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if (curr < user_filter) { |
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low = aTry + 1; |
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continue; |
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} |
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if (curr > user_filter) { |
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high = aTry - 1; |
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continue; |
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} |
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if (curr == user_filter) { |
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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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this.debug("lastTry="+lastTry); |
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|
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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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|
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BFilter.prototype.filter = function (user_filter) { |
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this.debug("set timeout for "+this.obj_count+" to "+this.timeout); |
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if (this.timeout_handle) { |
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clearTimeout(this.timeout_handle); |
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this.timeout_handle = null; |
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} |
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this.timeout_handle=setTimeout("top.__bfilter_obj["+this.obj_count+"].show_filter('"+user_filter.replace(/'/,"\\'")+"');", this.timeout); |
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return true; |
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} |
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|
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BFilter.prototype.show_filter = function (user_filter) { |
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|
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this.show_status("Showing entries with <em>"+user_filter+"</em>\n"); |
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|
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if (this.timeout_handle) { |
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clearTimeout(this.timeout_handle); |
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this.timeout_handle = null; |
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this.debug("timeout cleared"); |
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} |
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|
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this.clear_results(); |
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this.hits = 0; |
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|
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if (user_filter.length < this.min_len) { |
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this.show_status(); |
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return; |
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} |
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|
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var user_filter_lc = user_filter.toLowerCase(); |
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|
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this.debug("filter: '"+user_filter_lc+"'"); |
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|
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var part = user_filter_lc.substr(0,this.min_len); |
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|
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// no part found |
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if (! this.arr[part]) { |
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this.show_status(" for <em>"+user_filter+"</em><br>"); |
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this.debug("no part "+part); |
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return; |
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} |
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|
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// start anim icon |
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//<img src=\"pie.gif\"> Please wait, filtering... |
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|
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var i; |
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|
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// full part? (optimization) |
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if (user_filter.length == this.min_len) { |
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for (i = 0; i < this.arr[part].length; i++) { |
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this.result(this.arr[part][i]); |
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this.hits++; |
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} |
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this.show_results(); |
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} else { |
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|
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var from = this.binarySearch(this.arr[part], user_filter_lc); |
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|
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if (from != null) { |
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|
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this.debug("loop "+from+" ... "+this.arr[part].length); |
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|
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for(i = from ; i < this.arr[part].length ; i++) { |
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if (this.arr[part][i][0].substring(0,user_filter.length).toLowerCase() != user_filter_lc) { |
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this.debug("loop exit at "+i); |
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break; |
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} |
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this.result(this.arr[part][i]); |
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this.hits++; |
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} |
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|
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this.show_results(); |
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} |
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|
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} |
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|
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this.show_status(" for <em>"+user_filter+"</em>"); |
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|
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} |
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