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// Copyright (c) 2012, Christopher Ramey | http://github.com/cramey/tidx/blob/master/LICENCE
var Tidx = function() { // _index is the weighted, field-based reversed search term index
this._index = {};
// regex used to find terms inside a value
this.v_rx = new RegExp('(:?[a-z_-]+)|(\\d*\\.\\d+)|(\\d+)', 'mg');
// regex used to break out terms within a search
this.s_rx = new RegExp('(:?([a-z\\d-_]+):){0,1}(:?(:?"(.+?)")|([a-z_-]+)|(\\d*\\.\\d+)|(\\d+))', 'img')
// Indexes data inside this object.
this.index = function(tokenize, id, field, value) { var f; switch(typeof field){ // Don't allow undefined fields
case 'undefined': return; case 'string': f = field.toLowerCase(); break; default: f = String(field); }
var v; switch(typeof value){ // Don't allow undefined, null or object values
case 'null': case 'undefined': case 'object': return;
case 'string': v = value.toLowerCase(); // Don't index empty fields
if(v.length === 0){ return; } break;
default: v = String(value); }
// Add field to field list, as needed
if(this._index[f] === undefined){ this._index[f] = {}; }
if(tokenize === true){ // Iterate over discrete searchable terms
var re; while((re = this.v_rx.exec(v)) !== null){ var t = re[0]; // If the field in question doesn't have this term already,
// add it.
if(this._index[f][t] === undefined){ this._index[f][t] = {}; }
// Add this id to the reverse index under specific field (f)
// and term (v), if it already exists, increment the weight
if(this._index[f][t][id] === undefined){ this._index[f][t][id] = 1; } else { this._index[f][t][id]++; } } } else { if(this._index[f][v] === undefined){ this._index[f][v] = {}; } if(this._index[f][v][id] === undefined){ this._index[f][v][id] = 1; } else { this._index[f][v][id]++; } } };
// Conducts a global index scan for a string (value), iterating
// through all fields. Returns the number of terms it scanned for.
this.global_scan = function(value, result) { // Refuse empty searches
if(value.length === 0){ return 0; }
var v = value.toLowerCase();
// Loop over every field
for(var f in this._index){ // Look for the specified search term
if(this._index[f][v] !== undefined){ // If it exists, add the result to r, adding in the weight and count
for(var i in this._index[f][v]){ if(result[i] === undefined){ result[i] = {'w': 0, 'c': 0}; } result[i]['w'] += this._index[f][v][i]; result[i]['c']++; } } }
return 1; };
// Conducts a field specific scan for a string (value), returns
// the number of terms it scanned for.
this.field_scan = function(field, value, result) { var f; switch(typeof field){ // Don't allow undefined fields
case 'undefined': return 0; case 'string': f = field.toLowerCase(); break; default: f = String(field); }
if(value.length === 0){ return 0; } var v = value.toLowerCase();
if(this._index[f] === undefined || this._index[f][v] === undefined){ return 1; }
for(var i in this._index[f][v]){ if(result[i] === undefined){ result[i] = {'w': 0, 'c': 0}; } result[i]['w'] += this._index[f][v][i]; result[i]['c']++; }
return 1; };
// Raw searching function useful for chaining seaches
this.raw_search = function(search, result) { var re, tc=0; while((re = this.s_rx.exec(search)) !== null){ var field = re[2];
var value; for(var i=5; i < 9; i++){ if(re[i] !== undefined && re[i].length !== 0){ value = re[i]; break; } }
// Field specific scan for term
if(field !== undefined && field.length !== 0){ tc += this.field_scan(field, value, result); // Global scan for term
} else { tc += this.global_scan(value, result); } }
return tc; }
// Multi-term searching function. This is what you should use
// to search with in most cases. If and_query is true, returned
// results must match every term. Otherwise, any ID matching any
// term is returned.
this.search = function(and_query, search) { var r = {}; var tc = this.raw_search(search, r);
return this.order(r, (and_query ? tc : 0)); };
// Orders the result of a query. Accepts an object as a result, and
// the minimum floor count. In the event of an AND query, floor should
// be quality to the number of search terms. Otherwise it should be zero.
this.order = function(result, floor) { var t = [];
for(var i in result){ if(floor == 0 || result[i]['c'] >= floor){ t.push([i, result[i]['w']]); } }
t.sort(function(a,b){ return b[1] - a[1]; });
var r = []; for(var i in t){ r.push(t[i][0]); }
return r; }; };
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