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<?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) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
* @version $Id: MultiTerm.php 18954 2009-11-12 20:01:33Z alexander $
*/
/** Zend_Search_Lucene_Search_Query */
require_once 'Zend/Search/Lucene/Search/Query.php';
/**
* @category Zend
* @package Zend_Search_Lucene
* @subpackage Search
* @copyright Copyright (c) 2005-2009 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_MultiTerm extends Zend_Search_Lucene_Search_Query
{
/**
* Terms to find.
* Array of Zend_Search_Lucene_Index_Term
*
* @var array
*/
private $_terms = array();
/**
* Term signs.
* If true then term is required.
* If false then term is prohibited.
* If null then term is neither prohibited, nor required
*
* If array is null then all terms are required
*
* @var array
*/
private $_signs;
/**
* Result vector.
*
* @var array
*/
private $_resVector = null;
/**
* Terms positions vectors.
* Array of Arrays:
* term1Id => (docId => freq, ...)
* term2Id => (docId => freq, ...)
*
* @var array
*/
private $_termsFreqs = array();
/**
* A score factor based on the fraction of all query terms
* that a document contains.
* float for conjunction queries
* array of float for non conjunction queries
*
* @var mixed
*/
private $_coord = null;
/**
* Terms weights
* array of Zend_Search_Lucene_Search_Weight
*
* @var array
*/
private $_weights = array();
/**
* Class constructor. Create a new multi-term query object.
*
* if $signs array is omitted then all terms are required
* it differs from addTerm() behavior, but should never be used
*
* @param array $terms Array of Zend_Search_Lucene_Index_Term objects
* @param array $signs Array of signs. Sign is boolean|null.
* @throws Zend_Search_Lucene_Exception
*/
public function __construct($terms = null, $signs = null)
{
if (is_array($terms)) {
require_once 'Zend/Search/Lucene.php';
if (count($terms) > Zend_Search_Lucene::getTermsPerQueryLimit()) {
throw new Zend_Search_Lucene_Exception('Terms per query limit is reached.');
}
$this->_terms = $terms;
$this->_signs = null;
// Check if all terms are required
if (is_array($signs)) {
foreach ($signs as $sign ) {
if ($sign !== true) {
$this->_signs = $signs;
break;
}
}
}
}
}
/**
* Add a $term (Zend_Search_Lucene_Index_Term) to this query.
*
* The sign is specified as:
* TRUE - term is required
* FALSE - term is prohibited
* NULL - term is neither prohibited, nor required
*
* @param Zend_Search_Lucene_Index_Term $term
* @param boolean|null $sign
* @return void
*/
public function addTerm(Zend_Search_Lucene_Index_Term $term, $sign = null) {
if ($sign !== true || $this->_signs !== null) { // Skip, if all terms are required
if ($this->_signs === null) { // Check, If all previous terms are required
$this->_signs = array();
foreach ($this->_terms as $prevTerm) {
$this->_signs[] = true;
}
}
$this->_signs[] = $sign;
}
$this->_terms[] = $term;
}
/**
* 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 $index)
{
if (count($this->_terms) == 0) {
require_once 'Zend/Search/Lucene/Search/Query/Empty.php';
return new Zend_Search_Lucene_Search_Query_Empty();
}
// Check, that all fields are qualified
$allQualified = true;
foreach ($this->_terms as $term) {
if ($term->field === null) {
$allQualified = false;
break;
}
}
if ($allQualified) {
return $this;
} else {
/** transform multiterm query to boolean and apply rewrite() method to subqueries. */
require_once 'Zend/Search/Lucene/Search/Query/Boolean.php';
$query = new Zend_Search_Lucene_Search_Query_Boolean();
$query->setBoost($this->getBoost());
require_once 'Zend/Search/Lucene/Search/Query/Term.php';
foreach ($this->_terms as $termId => $term) {
$subquery = new Zend_Search_Lucene_Search_Query_Term($term);
$query->addSubquery($subquery->rewrite($index),
($this->_signs === null)? true : $this->_signs[$termId]);
}
return $query;
}
}
/**
* Optimize query in the context of specified index
*
* @param Zend_Search_Lucene_Interface $index
* @return Zend_Search_Lucene_Search_Query
*/
public function optimize(Zend_Search_Lucene_Interface $index)
{
$terms = $this->_terms;
$signs = $this->_signs;
foreach ($terms as $id => $term) {
if (!$index->hasTerm($term)) {
if ($signs === null || $signs[$id] === true) {
// Term is required
require_once 'Zend/Search/Lucene/Search/Query/Empty.php';
return new Zend_Search_Lucene_Search_Query_Empty();
} else {
// Term is optional or prohibited
// Remove it from terms and signs list
unset($terms[$id]);
unset($signs[$id]);
}
}
}
// Check if all presented terms are prohibited
$allProhibited = true;
if ($signs === null) {
$allProhibited = false;
} else {
foreach ($signs as $sign) {
if ($sign !== false) {
$allProhibited = false;
break;
}
}
}
if ($allProhibited) {
require_once 'Zend/Search/Lucene/Search/Query/Empty.php';
return new Zend_Search_Lucene_Search_Query_Empty();
}
/**
* @todo make an optimization for repeated terms
* (they may have different signs)
*/
if (count($terms) == 1) {
// It's already checked, that it's not a prohibited term
// It's one term query with one required or optional element
require_once 'Zend/Search/Lucene/Search/Query/Term.php';
$optimizedQuery = new Zend_Search_Lucene_Search_Query_Term(reset($terms));
$optimizedQuery->setBoost($this->getBoost());
return $optimizedQuery;
}
if (count($terms) == 0) {
require_once 'Zend/Search/Lucene/Search/Query/Empty.php';
return new Zend_Search_Lucene_Search_Query_Empty();
}
$optimizedQuery = new Zend_Search_Lucene_Search_Query_MultiTerm($terms, $signs);
$optimizedQuery->setBoost($this->getBoost());
return $optimizedQuery;
}
/**
* Returns query term
*
* @return array
*/
public function getTerms()
{
return $this->_terms;
}
/**
* Return terms signs
*
* @return array
*/
public function getSigns()
{
return $this->_signs;
}
/**
* Set weight for specified term
*
* @param integer $num
* @param Zend_Search_Lucene_Search_Weight_Term $weight
*/
public function setWeight($num, $weight)
{
$this->_weights[$num] = $weight;
}
/**
* Constructs an appropriate Weight implementation for this query.
*
* @param Zend_Search_Lucene_Interface $reader
* @return Zend_Search_Lucene_Search_Weight
*/
public function createWeight(Zend_Search_Lucene_Interface $reader)
{
require_once 'Zend/Search/Lucene/Search/Weight/MultiTerm.php';
$this->_weight = new Zend_Search_Lucene_Search_Weight_MultiTerm($this, $reader);
return $this->_weight;
}
/**
* Calculate result vector for Conjunction query
* (like '+something +another')
*
* @param Zend_Search_Lucene_Interface $reader
*/
private function _calculateConjunctionResult(Zend_Search_Lucene_Interface $reader)
{
$this->_resVector = null;
if (count($this->_terms) == 0) {
$this->_resVector = array();
}
// Order terms by selectivity
$docFreqs = array();
$ids = array();
foreach ($this->_terms as $id => $term) {
$docFreqs[] = $reader->docFreq($term);
$ids[] = $id; // Used to keep original order for terms with the same selectivity and omit terms comparison
}
array_multisort($docFreqs, SORT_ASC, SORT_NUMERIC,
$ids, SORT_ASC, SORT_NUMERIC,
$this->_terms);
require_once 'Zend/Search/Lucene/Index/DocsFilter.php';
$docsFilter = new Zend_Search_Lucene_Index_DocsFilter();
foreach ($this->_terms as $termId => $term) {
$termDocs = $reader->termDocs($term, $docsFilter);
}
// Treat last retrieved docs vector as a result set
// (filter collects data for other terms)
$this->_resVector = array_flip($termDocs);
foreach ($this->_terms as $termId => $term) {
$this->_termsFreqs[$termId] = $reader->termFreqs($term, $docsFilter);
}
// ksort($this->_resVector, SORT_NUMERIC);
// Docs are returned ordered. Used algorithms doesn't change elements order.
}
/**
* Calculate result vector for non Conjunction query
* (like '+something -another')
*
* @param Zend_Search_Lucene_Interface $reader
*/
private function _calculateNonConjunctionResult(Zend_Search_Lucene_Interface $reader)
{
$requiredVectors = array();
$requiredVectorsSizes = array();
$requiredVectorsIds = array(); // is used to prevent arrays comparison
$optional = array();
$prohibited = array();
foreach ($this->_terms as $termId => $term) {
$termDocs = array_flip($reader->termDocs($term));
if ($this->_signs[$termId] === true) {
// required
$requiredVectors[] = $termDocs;
$requiredVectorsSizes[] = count($termDocs);
$requiredVectorsIds[] = $termId;
} elseif ($this->_signs[$termId] === false) {
// prohibited
// array union
$prohibited += $termDocs;
} else {
// neither required, nor prohibited
// array union
$optional += $termDocs;
}
$this->_termsFreqs[$termId] = $reader->termFreqs($term);
}
// sort resvectors in order of subquery cardinality increasing
array_multisort($requiredVectorsSizes, SORT_ASC, SORT_NUMERIC,
$requiredVectorsIds, SORT_ASC, SORT_NUMERIC,
$requiredVectors);
$required = null;
foreach ($requiredVectors as $nextResVector) {
if($required === null) {
$required = $nextResVector;
} else {
//$required = array_intersect_key($required, $nextResVector);
/**
* This code is used as workaround for array_intersect_key() slowness problem.
*/
$updatedVector = array();
foreach ($required as $id => $value) {
if (isset($nextResVector[$id])) {
$updatedVector[$id] = $value;
}
}
$required = $updatedVector;
}
if (count($required) == 0) {
// Empty result set, we don't need to check other terms
break;
}
}
if ($required !== null) {
$this->_resVector = $required;
} else {
$this->_resVector = $optional;
}
if (count($prohibited) != 0) {
// $this->_resVector = array_diff_key($this->_resVector, $prohibited);
/**
* This code is used as workaround for array_diff_key() slowness problem.
*/
if (count($this->_resVector) < count($prohibited)) {
$updatedVector = $this->_resVector;
foreach ($this->_resVector as $id => $value) {
if (isset($prohibited[$id])) {
unset($updatedVector[$id]);
}
}
$this->_resVector = $updatedVector;
} else {
$updatedVector = $this->_resVector;
foreach ($prohibited as $id => $value) {
unset($updatedVector[$id]);
}
$this->_resVector = $updatedVector;
}
}
ksort($this->_resVector, SORT_NUMERIC);
}
/**
* Score calculator for conjunction queries (all terms are required)
*
* @param integer $docId
* @param Zend_Search_Lucene_Interface $reader
* @return float
*/
public function _conjunctionScore($docId, Zend_Search_Lucene_Interface $reader)
{
if ($this->_coord === null) {
$this->_coord = $reader->getSimilarity()->coord(count($this->_terms),
count($this->_terms) );
}
$score = 0.0;
foreach ($this->_terms as $termId => $term) {
/**
* We don't need to check that term freq is not 0
* Score calculation is performed only for matched docs
*/
$score += $reader->getSimilarity()->tf($this->_termsFreqs[$termId][$docId]) *
$this->_weights[$termId]->getValue() *
$reader->norm($docId, $term->field);
}
return $score * $this->_coord * $this->getBoost();
}
/**
* Score calculator for non conjunction queries (not all terms are required)
*
* @param integer $docId
* @param Zend_Search_Lucene_Interface $reader
* @return float
*/
public function _nonConjunctionScore($docId, $reader)
{
if ($this->_coord === null) {
$this->_coord = array();
$maxCoord = 0;
foreach ($this->_signs as $sign) {
if ($sign !== false /* not prohibited */) {
$maxCoord++;
}
}
for ($count = 0; $count <= $maxCoord; $count++) {
$this->_coord[$count] = $reader->getSimilarity()->coord($count, $maxCoord);
}
}
$score = 0.0;
$matchedTerms = 0;
foreach ($this->_terms as $termId=>$term) {
// Check if term is
if ($this->_signs[$termId] !== false && // not prohibited
isset($this->_termsFreqs[$termId][$docId]) // matched
) {
$matchedTerms++;
/**
* We don't need to check that term freq is not 0
* Score calculation is performed only for matched docs
*/
$score +=
$reader->getSimilarity()->tf($this->_termsFreqs[$termId][$docId]) *
$this->_weights[$termId]->getValue() *
$reader->norm($docId, $term->field);
}
}
return $score * $this->_coord[$matchedTerms] * $this->getBoost();
}
/**
* Execute query in context of index reader
* It also initializes necessary internal structures
*
* @param Zend_Search_Lucene_Interface $reader
* @param Zend_Search_Lucene_Index_DocsFilter|null $docsFilter
*/
public function execute(Zend_Search_Lucene_Interface $reader, $docsFilter = null)
{
if ($this->_signs === null) {
$this->_calculateConjunctionResult($reader);
} else {
$this->_calculateNonConjunctionResult($reader);
}
// Initialize weight if it's not done yet
$this->_initWeight($reader);
}
/**
* Get document ids likely matching the query
*
* It's an array with document ids as keys (performance considerations)
*
* @return array
*/
public function matchedDocs()
{
return $this->_resVector;
}
/**
* Score specified document
*
* @param integer $docId
* @param Zend_Search_Lucene_Interface $reader
* @return float
*/
public function score($docId, Zend_Search_Lucene_Interface $reader)
{
if (isset($this->_resVector[$docId])) {
if ($this->_signs === null) {
return $this->_conjunctionScore($docId, $reader);
} else {
return $this->_nonConjunctionScore($docId, $reader);
}
} else {
return 0;
}
}
/**
* Return query terms
*
* @return array
*/
public function getQueryTerms()
{
if ($this->_signs === null) {
return $this->_terms;
}
$terms = array();
foreach ($this->_signs as $id => $sign) {
if ($sign !== false) {
$terms[] = $this->_terms[$id];
}
}
return $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)
{
$words = array();
if ($this->_signs === null) {
foreach ($this->_terms as $term) {
$words[] = $term->text;
}
} else {
foreach ($this->_signs as $id => $sign) {
if ($sign !== false) {
$words[] = $this->_terms[$id]->text;
}
}
}
$highlighter->highlight($words);
}
/**
* Print a query
*
* @return string
*/
public function __toString()
{
// It's used only for query visualisation, so we don't care about characters escaping
$query = '';
foreach ($this->_terms as $id => $term) {
if ($id != 0) {
$query .= ' ';
}
if ($this->_signs === null || $this->_signs[$id] === true) {
$query .= '+';
} else if ($this->_signs[$id] === false) {
$query .= '-';
}
if ($term->field !== null) {
$query .= $term->field . ':';
}
$query .= $term->text;
}
if ($this->getBoost() != 1) {
$query = '(' . $query . ')^' . round($this->getBoost(), 4);
}
return $query;
}
}
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