File size: 10.93Kb
<?php
/**
* Zend Framework (http://framework.zend.com/)
*
* @link http://github.com/zendframework/zf2 for the canonical source repository
* @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
* @package Zend_Search
*/
namespace ZendSearch\Lucene\Search\Query;
use ZendSearch\Lucene;
use ZendSearch\Lucene\Analysis\Analyzer\Analyzer;
use ZendSearch\Lucene\Analysis\Analyzer\AnalyzerInterface;
use ZendSearch\Lucene\Exception\OutOfBoundsException;
use ZendSearch\Lucene\Exception\RuntimeException;
use ZendSearch\Lucene\Exception\UnsupportedMethodCallException;
use ZendSearch\Lucene\Index;
use ZendSearch\Lucene\Search\Highlighter\HighlighterInterface as Highlighter;
use Zend\Stdlib\ErrorHandler;
/**
* @category Zend
* @package Zend_Search_Lucene
* @subpackage Search
*/
class Wildcard extends AbstractQuery
{
/**
* Search pattern.
*
* Field has to be fully specified or has to be null
* Text may contain '*' or '?' symbols
*
* @var \ZendSearch\Lucene\Index\Term
*/
private $_pattern;
/**
* Matched terms.
*
* Matched terms list.
* It's filled during the search (rewrite operation) and may be used for search result
* post-processing
*
* Array of Zend_Search_Lucene_Index_Term objects
*
* @var array
*/
private $_matches = null;
/**
* Minimum term prefix length (number of minimum non-wildcard characters)
*
* @var integer
*/
private static $_minPrefixLength = 3;
/**
* Zend_Search_Lucene_Search_Query_Wildcard constructor.
*
* @param \ZendSearch\Lucene\Index\Term $pattern
*/
public function __construct(Index\Term $pattern)
{
$this->_pattern = $pattern;
}
/**
* Get minimum prefix length
*
* @return integer
*/
public static function getMinPrefixLength()
{
return self::$_minPrefixLength;
}
/**
* Set minimum prefix length
*
* @param integer $minPrefixLength
*/
public static function setMinPrefixLength($minPrefixLength)
{
self::$_minPrefixLength = $minPrefixLength;
}
/**
* Get terms prefix
*
* @param string $word
* @return string
*/
private static function _getPrefix($word)
{
$questionMarkPosition = strpos($word, '?');
$astrericPosition = strpos($word, '*');
if ($questionMarkPosition !== false) {
if ($astrericPosition !== false) {
return substr($word, 0, min($questionMarkPosition, $astrericPosition));
}
return substr($word, 0, $questionMarkPosition);
} elseif ($astrericPosition !== false) {
return substr($word, 0, $astrericPosition);
}
return $word;
}
/**
* Re-write query into primitive queries in the context of specified index
*
* @param \ZendSearch\Lucene\SearchIndexInterface $index
* @throws \ZendSearch\Lucene\Exception\RuntimeException
* @throws \ZendSearch\Lucene\Exception\OutOfBoundsException
* @return \ZendSearch\Lucene\Search\Query\AbstractQuery
*/
public function rewrite(Lucene\SearchIndexInterface $index)
{
$this->_matches = array();
if ($this->_pattern->field === null) {
// Search through all fields
$fields = $index->getFieldNames(true /* indexed fields list */);
} else {
$fields = array($this->_pattern->field);
}
$prefix = self::_getPrefix($this->_pattern->text);
$prefixLength = strlen($prefix);
$matchExpression = '/^' . str_replace(array('\\?', '\\*'), array('.', '.*') , preg_quote($this->_pattern->text, '/')) . '$/';
if ($prefixLength < self::$_minPrefixLength) {
throw new RuntimeException(
'At least ' . self::$_minPrefixLength . ' non-wildcard characters are required at the beginning of pattern.'
);
}
/**
* @todo check for PCRE unicode support may be performed through Zend_Environment in some future
*/
ErrorHandler::start(E_WARNING);
$result = preg_match('/\pL/u', 'a');
ErrorHandler::stop();
if ($result == 1) {
// PCRE unicode support is turned on
// add Unicode modifier to the match expression
$matchExpression .= 'u';
}
$maxTerms = Lucene\Lucene::getTermsPerQueryLimit();
foreach ($fields as $field) {
$index->resetTermsStream();
if ($prefix != '') {
$index->skipTo(new Index\Term($prefix, $field));
while ($index->currentTerm() !== null &&
$index->currentTerm()->field == $field &&
substr($index->currentTerm()->text, 0, $prefixLength) == $prefix) {
if (preg_match($matchExpression, $index->currentTerm()->text) === 1) {
$this->_matches[] = $index->currentTerm();
if ($maxTerms != 0 && count($this->_matches) > $maxTerms) {
throw new OutOfBoundsException('Terms per query limit is reached.');
}
}
$index->nextTerm();
}
} else {
$index->skipTo(new Index\Term('', $field));
while ($index->currentTerm() !== null && $index->currentTerm()->field == $field) {
if (preg_match($matchExpression, $index->currentTerm()->text) === 1) {
$this->_matches[] = $index->currentTerm();
if ($maxTerms != 0 && count($this->_matches) > $maxTerms) {
throw new OutOfBoundsException('Terms per query limit is reached.');
}
}
$index->nextTerm();
}
}
$index->closeTermsStream();
}
if (count($this->_matches) == 0) {
return new EmptyResult();
} elseif (count($this->_matches) == 1) {
return new Term(reset($this->_matches));
} else {
$rewrittenQuery = new MultiTerm();
foreach ($this->_matches as $matchedTerm) {
$rewrittenQuery->addTerm($matchedTerm);
}
return $rewrittenQuery;
}
}
/**
* Optimize query in the context of specified index
*
* @param \ZendSearch\Lucene\SearchIndexInterface $index
* @throws \ZendSearch\Lucene\Exception\UnsupportedMethodCallException
* @return \ZendSearch\Lucene\Search\Query\AbstractQuery
*/
public function optimize(Lucene\SearchIndexInterface $index)
{
throw new UnsupportedMethodCallException('Wildcard query should not be directly used for search. Use $query->rewrite($index)');
}
/**
* Returns query pattern
*
* @return \ZendSearch\Lucene\Index\Term
*/
public function getPattern()
{
return $this->_pattern;
}
/**
* Return query terms
*
* @throws \ZendSearch\Lucene\Exception\RuntimeException
* @return array
*/
public function getQueryTerms()
{
if ($this->_matches === null) {
throw new RuntimeException('Search has to be performed first to get matched terms');
}
return $this->_matches;
}
/**
* Constructs an appropriate Weight implementation for this query.
*
* @param \ZendSearch\Lucene\SearchIndexInterface $reader
* @throws \ZendSearch\Lucene\Exception\UnsupportedMethodCallException
*/
public function createWeight(Lucene\SearchIndexInterface $reader)
{
throw new UnsupportedMethodCallException('Wildcard query should not be directly used for search. Use $query->rewrite($index)');
}
/**
* Execute query in context of index reader
* It also initializes necessary internal structures
*
* @param \ZendSearch\Lucene\SearchIndexInterface $reader
* @param \ZendSearch\Lucene\Index\DocsFilter|null $docsFilter
* @throws \ZendSearch\Lucene\Exception\UnsupportedMethodCallException
*/
public function execute(Lucene\SearchIndexInterface $reader, $docsFilter = null)
{
throw new UnsupportedMethodCallException('Wildcard query should not be directly used for search. Use $query->rewrite($index)');
}
/**
* Get document ids likely matching the query
*
* It's an array with document ids as keys (performance considerations)
*
* @throws \ZendSearch\Lucene\Exception\UnsupportedMethodCallException
* @return array
*/
public function matchedDocs()
{
throw new UnsupportedMethodCallException(
'Wildcard query should not be directly used for search. Use $query->rewrite($index)'
);
}
/**
* Score specified document
*
* @param integer $docId
* @param \ZendSearch\Lucene\SearchIndexInterface $reader
* @throws \ZendSearch\Lucene\Exception\UnsupportedMethodCallException
* @return float
*/
public function score($docId, Lucene\SearchIndexInterface $reader)
{
throw new UnsupportedMethodCallException(
'Wildcard query should not be directly used for search. Use $query->rewrite($index)'
);
}
/**
* Query specific matches highlighting
*
* @param Highlighter $highlighter Highlighter object (also contains doc for highlighting)
*/
protected function _highlightMatches(Highlighter $highlighter)
{
$words = array();
$matchExpression = '/^' . str_replace(array('\\?', '\\*'), array('.', '.*') , preg_quote($this->_pattern->text, '/')) . '$/';
ErrorHandler::start(E_WARNING);
$result = preg_match('/\pL/u', 'a');
ErrorHandler::stop();
if ($result == 1) {
// PCRE unicode support is turned on
// add Unicode modifier to the match expression
$matchExpression .= 'u';
}
$docBody = $highlighter->getDocument()->getFieldUtf8Value('body');
$tokens = Analyzer::getDefault()->tokenize($docBody, 'UTF-8');
foreach ($tokens as $token) {
if (preg_match($matchExpression, $token->getTermText()) === 1) {
$words[] = $token->getTermText();
}
}
$highlighter->highlight($words);
}
/**
* 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->_pattern->field !== null) {
$query = $this->_pattern->field . ':';
} else {
$query = '';
}
$query .= $this->_pattern->text;
if ($this->getBoost() != 1) {
$query = $query . '^' . round($this->getBoost(), 4);
}
return $query;
}
}