web/Zend/Search/Lucene/Search/Query/Preprocessing/Fuzzy.php
changeset 0 4eba9c11703f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/Zend/Search/Lucene/Search/Query/Preprocessing/Fuzzy.php	Mon Dec 13 18:29:26 2010 +0100
@@ -0,0 +1,287 @@
+<?php
+/**
+ * Zend Framework
+ *
+ * LICENSE
+ *
+ * This source file is subject to the new BSD license that is bundled
+ * with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://framework.zend.com/license/new-bsd
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@zend.com so we can send you a copy immediately.
+ *
+ * @category   Zend
+ * @package    Zend_Search_Lucene
+ * @subpackage Search
+ * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ * @version    $Id: Fuzzy.php 20096 2010-01-06 02:05:09Z bkarwin $
+ */
+
+
+/** Zend_Search_Lucene_Search_Query_Processing */
+require_once 'Zend/Search/Lucene/Search/Query/Preprocessing.php';
+
+
+/**
+ * It's an internal abstract class intended to finalize ase a query processing after query parsing.
+ * This type of query is not actually involved into query execution.
+ *
+ * @category   Zend
+ * @package    Zend_Search_Lucene
+ * @subpackage Search
+ * @internal
+ * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license    http://framework.zend.com/license/new-bsd     New BSD License
+ */
+class Zend_Search_Lucene_Search_Query_Preprocessing_Fuzzy extends Zend_Search_Lucene_Search_Query_Preprocessing
+{
+    /**
+     * word (query parser lexeme) to find.
+     *
+     * @var string
+     */
+    private $_word;
+
+    /**
+     * Word encoding (field name is always provided using UTF-8 encoding since it may be retrieved from index).
+     *
+     * @var string
+     */
+    private $_encoding;
+
+
+    /**
+     * Field name.
+     *
+     * @var string
+     */
+    private $_field;
+
+    /**
+     * A value between 0 and 1 to set the required similarity
+     *  between the query term and the matching terms. For example, for a
+     *  _minimumSimilarity of 0.5 a term of the same length
+     *  as the query term is considered similar to the query term if the edit distance
+     *  between both terms is less than length(term)*0.5
+     *
+     * @var float
+     */
+    private $_minimumSimilarity;
+
+    /**
+     * Class constructor.  Create a new preprocessing object for prase query.
+     *
+     * @param string $word       Non-tokenized word (query parser lexeme) to search.
+     * @param string $encoding   Word encoding.
+     * @param string $fieldName  Field name.
+     * @param float  $minimumSimilarity minimum similarity
+     */
+    public function __construct($word, $encoding, $fieldName, $minimumSimilarity)
+    {
+        $this->_word     = $word;
+        $this->_encoding = $encoding;
+        $this->_field    = $fieldName;
+        $this->_minimumSimilarity = $minimumSimilarity;
+    }
+
+    /**
+     * Re-write query into primitive queries in the context of specified index
+     *
+     * @param Zend_Search_Lucene_Interface $index
+     * @return Zend_Search_Lucene_Search_Query
+     */
+    public function rewrite(Zend_Search_Lucene_Interface $index)
+    {
+        if ($this->_field === null) {
+            require_once 'Zend/Search/Lucene/Search/Query/Boolean.php';
+            $query = new Zend_Search_Lucene_Search_Query_Boolean();
+
+            $hasInsignificantSubqueries = false;
+
+            require_once 'Zend/Search/Lucene.php';
+            if (Zend_Search_Lucene::getDefaultSearchField() === null) {
+                $searchFields = $index->getFieldNames(true);
+            } else {
+                $searchFields = array(Zend_Search_Lucene::getDefaultSearchField());
+            }
+
+            require_once 'Zend/Search/Lucene/Search/Query/Preprocessing/Fuzzy.php';
+            foreach ($searchFields as $fieldName) {
+                $subquery = new Zend_Search_Lucene_Search_Query_Preprocessing_Fuzzy($this->_word,
+                                                                                    $this->_encoding,
+                                                                                    $fieldName,
+                                                                                    $this->_minimumSimilarity);
+
+                $rewrittenSubquery = $subquery->rewrite($index);
+
+                if ( !($rewrittenSubquery instanceof Zend_Search_Lucene_Search_Query_Insignificant  ||
+                       $rewrittenSubquery instanceof Zend_Search_Lucene_Search_Query_Empty) ) {
+                    $query->addSubquery($rewrittenSubquery);
+                }
+
+                if ($rewrittenSubquery instanceof Zend_Search_Lucene_Search_Query_Insignificant) {
+                    $hasInsignificantSubqueries = true;
+                }
+            }
+
+            $subqueries = $query->getSubqueries();
+
+            if (count($subqueries) == 0) {
+                $this->_matches = array();
+                if ($hasInsignificantSubqueries) {
+                    require_once 'Zend/Search/Lucene/Search/Query/Insignificant.php';
+                    return new Zend_Search_Lucene_Search_Query_Insignificant();
+                } else {
+                    require_once 'Zend/Search/Lucene/Search/Query/Empty.php';
+                    return new Zend_Search_Lucene_Search_Query_Empty();
+                }
+            }
+
+            if (count($subqueries) == 1) {
+                $query = reset($subqueries);
+            }
+
+            $query->setBoost($this->getBoost());
+
+            $this->_matches = $query->getQueryTerms();
+            return $query;
+        }
+
+        // -------------------------------------
+        // Recognize exact term matching (it corresponds to Keyword fields stored in the index)
+        // encoding is not used since we expect binary matching
+        require_once 'Zend/Search/Lucene/Index/Term.php';
+        $term = new Zend_Search_Lucene_Index_Term($this->_word, $this->_field);
+        if ($index->hasTerm($term)) {
+            require_once 'Zend/Search/Lucene/Search/Query/Fuzzy.php';
+            $query = new Zend_Search_Lucene_Search_Query_Fuzzy($term, $this->_minimumSimilarity);
+            $query->setBoost($this->getBoost());
+
+            // Get rewritten query. Important! It also fills terms matching container.
+            $rewrittenQuery = $query->rewrite($index);
+            $this->_matches = $query->getQueryTerms();
+
+            return $rewrittenQuery;
+        }
+
+
+        // -------------------------------------
+        // Recognize wildcard queries
+
+        /** @todo check for PCRE unicode support may be performed through Zend_Environment in some future */
+        if (@preg_match('/\pL/u', 'a') == 1) {
+            $subPatterns = preg_split('/[*?]/u', iconv($this->_encoding, 'UTF-8', $this->_word));
+        } else {
+            $subPatterns = preg_split('/[*?]/', $this->_word);
+        }
+        if (count($subPatterns) > 1) {
+            require_once 'Zend/Search/Lucene/Search/QueryParserException.php';
+            throw new Zend_Search_Lucene_Search_QueryParserException('Fuzzy search doesn\'t support wildcards (except within Keyword fields).');
+        }
+
+
+        // -------------------------------------
+        // Recognize one-term multi-term and "insignificant" queries
+        require_once 'Zend/Search/Lucene/Analysis/Analyzer.php';
+        $tokens = Zend_Search_Lucene_Analysis_Analyzer::getDefault()->tokenize($this->_word, $this->_encoding);
+
+        if (count($tokens) == 0) {
+            $this->_matches = array();
+            require_once 'Zend/Search/Lucene/Search/Query/Insignificant.php';
+            return new Zend_Search_Lucene_Search_Query_Insignificant();
+        }
+
+        if (count($tokens) == 1) {
+            require_once 'Zend/Search/Lucene/Index/Term.php';
+            $term  = new Zend_Search_Lucene_Index_Term($tokens[0]->getTermText(), $this->_field);
+            require_once 'Zend/Search/Lucene/Search/Query/Fuzzy.php';
+            $query = new Zend_Search_Lucene_Search_Query_Fuzzy($term, $this->_minimumSimilarity);
+            $query->setBoost($this->getBoost());
+
+            // Get rewritten query. Important! It also fills terms matching container.
+            $rewrittenQuery = $query->rewrite($index);
+            $this->_matches = $query->getQueryTerms();
+
+            return $rewrittenQuery;
+        }
+
+        // Word is tokenized into several tokens
+        require_once 'Zend/Search/Lucene/Search/QueryParserException.php';
+        throw new Zend_Search_Lucene_Search_QueryParserException('Fuzzy search is supported only for non-multiple word terms');
+    }
+
+    /**
+     * Query specific matches highlighting
+     *
+     * @param Zend_Search_Lucene_Search_Highlighter_Interface $highlighter  Highlighter object (also contains doc for highlighting)
+     */
+    protected function _highlightMatches(Zend_Search_Lucene_Search_Highlighter_Interface $highlighter)
+    {
+        /** Skip fields detection. We don't need it, since we expect all fields presented in the HTML body and don't differentiate them */
+
+        /** Skip exact term matching recognition, keyword fields highlighting is not supported */
+
+        // -------------------------------------
+        // Recognize wildcard queries
+
+        /** @todo check for PCRE unicode support may be performed through Zend_Environment in some future */
+        if (@preg_match('/\pL/u', 'a') == 1) {
+            $subPatterns = preg_split('/[*?]/u', iconv($this->_encoding, 'UTF-8', $this->_word));
+        } else {
+            $subPatterns = preg_split('/[*?]/', $this->_word);
+        }
+        if (count($subPatterns) > 1) {
+            // Do nothing
+            return;
+        }
+
+
+        // -------------------------------------
+        // Recognize one-term multi-term and "insignificant" queries
+        require_once 'Zend/Search/Lucene/Analysis/Analyzer.php';
+        $tokens = Zend_Search_Lucene_Analysis_Analyzer::getDefault()->tokenize($this->_word, $this->_encoding);
+        if (count($tokens) == 0) {
+            // Do nothing
+            return;
+        }
+        if (count($tokens) == 1) {
+            require_once 'Zend/Search/Lucene/Index/Term.php';
+            $term  = new Zend_Search_Lucene_Index_Term($tokens[0]->getTermText(), $this->_field);
+            require_once 'Zend/Search/Lucene/Search/Query/Fuzzy.php';
+            $query = new Zend_Search_Lucene_Search_Query_Fuzzy($term, $this->_minimumSimilarity);
+
+            $query->_highlightMatches($highlighter);
+            return;
+        }
+
+        // Word is tokenized into several tokens
+        // But fuzzy search is supported only for non-multiple word terms
+        // Do nothing
+    }
+
+    /**
+     * Print a query
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        // It's used only for query visualisation, so we don't care about characters escaping
+        if ($this->_field !== null) {
+            $query = $this->_field . ':';
+        } else {
+            $query = '';
+        }
+
+        $query .= $this->_word;
+
+        if ($this->getBoost() != 1) {
+            $query .= '^' . round($this->getBoost(), 4);
+        }
+
+        return $query;
+    }
+}