git.roojs.org Git - web.mtrack/blob - Zend/Search/Lucene/Search/Weight/Phrase.php

   1 <?php
   2 /**
   3  * Zend Framework
   4  *
   5  * LICENSE
   6  *
   7  * This source file is subject to the new BSD license that is bundled
   8  * with this package in the file LICENSE.txt.
   9  * It is also available through the world-wide-web at this URL:
  10  * http://framework.zend.com/license/new-bsd
  11  * If you did not receive a copy of the license and are unable to
  12  * obtain it through the world-wide-web, please send an email
  13  * to license@zend.com so we can send you a copy immediately.
  14  *
  15  * @category   Zend
  16  * @package    Zend_Search_Lucene
  17  * @subpackage Search
  18  * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
  19  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  20  * @version    $Id: Phrase.php 16541 2009-07-07 06:59:03Z bkarwin $
  21  */
  22
  23
  24 /**
  25  * Zend_Search_Lucene_Search_Weight
  26  */
  27 require_once 'Zend/Search/Lucene/Search/Weight.php';
  28
  29
  30 /**
  31  * @category   Zend
  32  * @package    Zend_Search_Lucene
  33  * @subpackage Search
  34  * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
  35  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  36  */
  37 class Zend_Search_Lucene_Search_Weight_Phrase extends Zend_Search_Lucene_Search_Weight
  38 {
  39     /**
  40      * IndexReader.
  41      *
  42      * @var Zend_Search_Lucene_Interface
  43      */
  44     private $_reader;
  45
  46     /**
  47      * The query that this concerns.
  48      *
  49      * @var Zend_Search_Lucene_Search_Query_Phrase
  50      */
  51     private $_query;
  52
  53     /**
  54      * Score factor
  55      *
  56      * @var float
  57      */
  58     private $_idf;
  59
  60     /**
  61      * Zend_Search_Lucene_Search_Weight_Phrase constructor
  62      *
  63      * @param Zend_Search_Lucene_Search_Query_Phrase $query
  64      * @param Zend_Search_Lucene_Interface           $reader
  65      */
  66     public function __construct(Zend_Search_Lucene_Search_Query_Phrase $query,
  67                                 Zend_Search_Lucene_Interface           $reader)
  68     {
  69         $this->_query  = $query;
  70         $this->_reader = $reader;
  71     }
  72
  73     /**
  74      * The sum of squared weights of contained query clauses.
  75      *
  76      * @return float
  77      */
  78     public function sumOfSquaredWeights()
  79     {
  80         // compute idf
  81         $this->_idf = $this->_reader->getSimilarity()->idf($this->_query->getTerms(), $this->_reader);
  82
  83         // compute query weight
  84         $this->_queryWeight = $this->_idf * $this->_query->getBoost();
  85
  86         // square it
  87         return $this->_queryWeight * $this->_queryWeight;
  88     }
  89
  90
  91     /**
  92      * Assigns the query normalization factor to this.
  93      *
  94      * @param float $queryNorm
  95      */
  96     public function normalize($queryNorm)
  97     {
  98         $this->_queryNorm = $queryNorm;
  99
 100         // normalize query weight
 101         $this->_queryWeight *= $queryNorm;
 102
 103         // idf for documents
 104         $this->_value = $this->_queryWeight * $this->_idf;
 105     }
 106 }
 107
 108