/library/Zend/Search/Lucene/Search/Query/Preprocessing/Fuzzy.php
PHP | 286 lines | 127 code | 44 blank | 115 comment | 32 complexity | cfdf9ae9bd5fe252d19b06a36592ff8c MD5 | raw file
- <?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 $Id$
- */
- /**
- * @namespace
- */
- namespace Zend\Search\Lucene\Search\Query\Preprocessing;
- use Zend\Search\Lucene;
- use Zend\Search\Lucene\Search\Query;
- use Zend\Search\Lucene\Index;
- use Zend\Search\Lucene\Search;
- use Zend\Search\Lucene\Analysis\Analyzer;
- use Zend\Search\Lucene\Search\Highlighter;
- /**
- * 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.
- *
- * @uses \Zend\Search\Lucene\Index
- * @uses \Zend\Search\Lucene\Analysis\Analyzer
- * @uses \Zend\Search\Lucene\Index\Term
- * @uses \Zend\Search\Lucene\Search\QueryParserException
- * @uses \Zend\Search\Lucene\Search\Query\Boolean
- * @uses \Zend\Search\Lucene\Search\Query\EmptyResult
- * @uses \Zend\Search\Lucene\Search\Query\Fuzzy
- * @uses \Zend\Search\Lucene\Search\Query\Insignificant
- * @uses \Zend\Search\Lucene\Search\Query\Preprocessing\AbstractPreprocessing
- * @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 Fuzzy extends AbstractPreprocessing
- {
- /**
- * 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\SearchIndex $index
- * @return \Zend\Search\Lucene\Search\Query\AbstractQuery
- */
- public function rewrite(Lucene\SearchIndex $index)
- {
- if ($this->_field === null) {
- $query = new Search\Query\Boolean();
- $hasInsignificantSubqueries = false;
- if (Lucene\Lucene::getDefaultSearchField() === null) {
- $searchFields = $index->getFieldNames(true);
- } else {
- $searchFields = array(Lucene\Lucene::getDefaultSearchField());
- }
- foreach ($searchFields as $fieldName) {
- $subquery = new self($this->_word,
- $this->_encoding,
- $fieldName,
- $this->_minimumSimilarity);
- $rewrittenSubquery = $subquery->rewrite($index);
- if ( !($rewrittenSubquery instanceof Query\Insignificant ||
- $rewrittenSubquery instanceof Query\EmptyResult) ) {
- $query->addSubquery($rewrittenSubquery);
- }
- if ($rewrittenSubquery instanceof Query\Insignificant) {
- $hasInsignificantSubqueries = true;
- }
- }
- $subqueries = $query->getSubqueries();
- if (count($subqueries) == 0) {
- $this->_matches = array();
- if ($hasInsignificantSubqueries) {
- return new Query\Insignificant();
- } else {
- return new Query\EmptyResult();
- }
- }
- 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
- $term = new Index\Term($this->_word, $this->_field);
- if ($index->hasTerm($term)) {
- $query = new Query\Fuzzy($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) {
- throw new Search\QueryParserException('Fuzzy search doesn\'t support wildcards (except within Keyword fields).');
- }
- // -------------------------------------
- // Recognize one-term multi-term and "insignificant" queries
- $tokens = Analyzer\Analyzer::getDefault()->tokenize($this->_word, $this->_encoding);
- if (count($tokens) == 0) {
- $this->_matches = array();
- return new Query\Insignificant();
- }
- if (count($tokens) == 1) {
- $term = new Index\Term($tokens[0]->getTermText(), $this->_field);
- $query = new Query\Fuzzy($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
- throw new Search\QueryParserException('Fuzzy search is supported only for non-multiple word terms');
- }
- /**
- * Query specific matches highlighting
- *
- * @param \Zend\Search\Lucene\Search\Highlighter $highlighter Highlighter object (also contains doc for highlighting)
- */
- protected function _highlightMatches(Highlighter $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
- $tokens = Analyzer\Analyzer::getDefault()->tokenize($this->_word, $this->_encoding);
- if (count($tokens) == 0) {
- // Do nothing
- return;
- }
- if (count($tokens) == 1) {
- $term = new Index\Term($tokens[0]->getTermText(), $this->_field);
- $query = new Query\Fuzzy($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;
- }
- }