/**
* Transforms a generic Query object into an Elastic Search query DSL
*
* @param Query $query
*/
public function mapQuery(Query $query)
{
$arguments = array();
$map = new Boolean();
if ($query->hasQueryString()) {
Lucene::setDefaultSearchField($query->getQueryString()->getDefaultField());
QueryParser::setDefaultOperator($query->getQueryString()->getDefaultOperator() == Query::OPERATOR_AND ? QueryParser::B_AND : QueryParser::B_OR);
$keyword = $query->getQueryString()->getQuery();
if ("*" === $keyword) {
$subQuery = new Wildcard(new Term($keyword));
$subQuery->setMinPrefixLength(0);
} else {
$subQuery = QueryParser::parse($keyword);
}
$map->addSubquery($subQuery, true);
}
$arguments[] = $map;
foreach ($query->getSort() as $sort) {
$arguments[] = key($sort);
$arguments[] = SORT_REGULAR;
$arguments[] = current($sort) == 'asc' ? SORT_ASC : SORT_DESC;
}
return $arguments;
}
/**
* Generate 'boolean style' query from the context
* 'term1 and term2 or term3 and (<subquery1>) and not (<subquery2>)'
*
* @throws \Zend\Search\Lucene\Search\Exception\QueryParserException
* @return \Zend\Search\Lucene\Search\Query\AbstractQuery
*/
private function _booleanExpressionQuery()
{
/**
* We treat each level of an expression as a boolean expression in
* a Disjunctive Normal Form
*
* AND operator has higher precedence than OR
*
* Thus logical query is a disjunction of one or more conjunctions of
* one or more query entries
*/
$expressionRecognizer = new BooleanExpressionRecognizer();
try {
foreach ($this->_entries as $entry) {
if ($entry instanceof QueryEntry\AbstractQueryEntry) {
$expressionRecognizer->processLiteral($entry);
} else {
switch ($entry) {
case QueryToken::TT_AND_LEXEME:
$expressionRecognizer->processOperator(BooleanExpressionRecognizer::IN_AND_OPERATOR);
break;
case QueryToken::TT_OR_LEXEME:
$expressionRecognizer->processOperator(BooleanExpressionRecognizer::IN_OR_OPERATOR);
break;
case QueryToken::TT_NOT_LEXEME:
$expressionRecognizer->processOperator(BooleanExpressionRecognizer::IN_NOT_OPERATOR);
break;
default:
throw new UnexpectedValueException('Boolean expression error. Unknown operator type.');
}
}
}
$conjuctions = $expressionRecognizer->finishExpression();
} catch (\Zend\Search\Lucene\Exception $e) {
// It's query syntax error message and it should be user friendly. So FSM message is omitted
throw new QueryParserException('Boolean expression error.', 0, $e);
}
// Remove 'only negative' conjunctions
foreach ($conjuctions as $conjuctionId => $conjuction) {
$nonNegativeEntryFound = false;
foreach ($conjuction as $conjuctionEntry) {
if ($conjuctionEntry[1]) {
$nonNegativeEntryFound = true;
break;
}
}
if (!$nonNegativeEntryFound) {
unset($conjuctions[$conjuctionId]);
}
}
$subqueries = array();
foreach ($conjuctions as $conjuction) {
// Check, if it's a one term conjuction
if (count($conjuction) == 1) {
$subqueries[] = $conjuction[0][0]->getQuery($this->_encoding);
} else {
$subquery = new Query\Boolean();
foreach ($conjuction as $conjuctionEntry) {
$subquery->addSubquery($conjuctionEntry[0]->getQuery($this->_encoding), $conjuctionEntry[1]);
}
$subqueries[] = $subquery;
}
}
if (count($subqueries) == 0) {
return new Query\Insignificant();
}
if (count($subqueries) == 1) {
return $subqueries[0];
}
$query = new Query\Boolean();
foreach ($subqueries as $subquery) {
// Non-requirered entry/subquery
$query->addSubquery($subquery);
}
return $query;
}
/**
* 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 $index)
{
if (count($this->_terms) == 0) {
return new EmptyResult();
} else if ($this->_terms[0]->field !== null) {
return $this;
} else {
$query = new Boolean();
$query->setBoost($this->getBoost());
foreach ($index->getFieldNames(true) as $fieldName) {
$subquery = new self();
$subquery->setSlop($this->getSlop());
foreach ($this->_terms as $termId => $term) {
$qualifiedTerm = new Index\Term($term->text, $fieldName);
$subquery->addTerm($qualifiedTerm, $this->_offsets[$termId]);
}
$query->addSubquery($subquery);
}
return $query;
}
}
/**
* Re-write query into primitive queries in the context of specified index
*
* @param \Zend\Search\Lucene\SearchIndexInterface $index
* @return \Zend\Search\Lucene\Search\Query\AbstractQuery
*/
public function rewrite(Lucene\SearchIndexInterface $index)
{
// Allow to use wildcards within phrases
// They are either removed by text analyzer or used as a part of keyword for keyword fields
//
// if (strpos($this->_phrase, '?') !== false || strpos($this->_phrase, '*') !== false) {
// require_once 'Zend/Search/Lucene/Search/QueryParserException.php';
// throw new Zend_Search_Lucene_Search_QueryParserException('Wildcards are only allowed in a single terms.');
// }
// Split query into subqueries if field name is not specified
if ($this->_field === null) {
$query = new Query\Boolean();
$query->setBoost($this->getBoost());
if (Lucene\Lucene::getDefaultSearchField() === null) {
$searchFields = $index->getFieldNames(true);
} else {
$searchFields = array(Lucene\Lucene::getDefaultSearchField());
}
foreach ($searchFields as $fieldName) {
$subquery = new Phrase($this->_phrase, $this->_phraseEncoding, $fieldName);
$subquery->setSlop($this->getSlop());
$query->addSubquery($subquery->rewrite($index));
}
$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->_phrase, $this->_field);
if ($index->hasTerm($term)) {
$query = new Query\Term($term);
$query->setBoost($this->getBoost());
$this->_matches = $query->getQueryTerms();
return $query;
}
// tokenize phrase using current analyzer and process it as a phrase query
$tokens = Analyzer::getDefault()->tokenize($this->_phrase, $this->_phraseEncoding);
if (count($tokens) == 0) {
$this->_matches = array();
return new Query\Insignificant();
}
if (count($tokens) == 1) {
$term = new Index\Term($tokens[0]->getTermText(), $this->_field);
$query = new Query\Term($term);
$query->setBoost($this->getBoost());
$this->_matches = $query->getQueryTerms();
return $query;
}
//It's non-trivial phrase query
$position = -1;
$query = new Query\Phrase();
foreach ($tokens as $token) {
$position += $token->getPositionIncrement();
$term = new Index\Term($token->getTermText(), $this->_field);
$query->addTerm($term, $position);
$query->setSlop($this->getSlop());
}
$this->_matches = $query->getQueryTerms();
return $query;
}
/**
* 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 $index)
{
if (count($this->_terms) == 0) {
return new EmptyResult();
}
// 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. */
$query = new Boolean();
$query->setBoost($this->getBoost());
foreach ($this->_terms as $termId => $term) {
$subquery = new Term($term);
$query->addSubquery($subquery->rewrite($index), $this->_signs === null ? true : $this->_signs[$termId]);
}
return $query;
}
}
/**
* Re-write query into primitive queries in the context of specified index
*
* @param \Zend\Search\Lucene\IndexInterface $index
* @return \Zend\Search\Lucene\Search\Query\AbstractQuery
* @throws \Zend\Search\Lucene\Exception
*/
public function rewrite(Lucene\IndexInterface $index)
{
$this->_matches = array();
$this->_scores = array();
$this->_termKeys = array();
if ($this->_term->field === null) {
// Search through all fields
$fields = $index->getFieldNames(true);
} else {
$fields = array($this->_term->field);
}
$prefix = Index\Term::getPrefix($this->_term->text, $this->_prefixLength);
$prefixByteLength = strlen($prefix);
$prefixUtf8Length = Index\Term::getLength($prefix);
$termLength = Index\Term::getLength($this->_term->text);
$termRest = substr($this->_term->text, $prefixByteLength);
// we calculate length of the rest in bytes since levenshtein() is not UTF-8 compatible
$termRestLength = strlen($termRest);
$scaleFactor = 1 / (1 - $this->_minimumSimilarity);
$maxTerms = Lucene\Lucene::getTermsPerQueryLimit();
foreach ($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, $prefixByteLength) == $prefix) {
// Calculate similarity
$target = substr($index->currentTerm()->text, $prefixByteLength);
$maxDistance = isset($this->_maxDistances[strlen($target)]) ? $this->_maxDistances[strlen($target)] : $this->_calculateMaxDistance($prefixUtf8Length, $termRestLength, strlen($target));
if ($termRestLength == 0) {
// we don't have anything to compare. That means if we just add
// the letters for current term we get the new word
$similarity = $prefixUtf8Length == 0 ? 0 : 1 - strlen($target) / $prefixUtf8Length;
} else {
if (strlen($target) == 0) {
$similarity = $prefixUtf8Length == 0 ? 0 : 1 - $termRestLength / $prefixUtf8Length;
} else {
if ($maxDistance < abs($termRestLength - strlen($target))) {
//just adding the characters of term to target or vice-versa results in too many edits
//for example "pre" length is 3 and "prefixes" length is 8. We can see that
//given this optimal circumstance, the edit distance cannot be less than 5.
//which is 8-3 or more precisesly abs(3-8).
//if our maximum edit distance is 4, then we can discard this word
//without looking at it.
$similarity = 0;
} else {
$similarity = 1 - levenshtein($termRest, $target) / ($prefixUtf8Length + min($termRestLength, strlen($target)));
}
}
}
if ($similarity > $this->_minimumSimilarity) {
$this->_matches[] = $index->currentTerm();
$this->_termKeys[] = $index->currentTerm()->key();
$this->_scores[] = ($similarity - $this->_minimumSimilarity) * $scaleFactor;
if ($maxTerms != 0 && count($this->_matches) > $maxTerms) {
throw new Lucene\Exception('Terms per query limit is reached.');
}
}
$index->nextTerm();
}
} else {
$index->skipTo(new Index\Term('', $field));
while ($index->currentTerm() !== null && $index->currentTerm()->field == $field) {
// Calculate similarity
$target = $index->currentTerm()->text;
$maxDistance = isset($this->_maxDistances[strlen($target)]) ? $this->_maxDistances[strlen($target)] : $this->_calculateMaxDistance(0, $termRestLength, strlen($target));
if ($maxDistance < abs($termRestLength - strlen($target))) {
//just adding the characters of term to target or vice-versa results in too many edits
//for example "pre" length is 3 and "prefixes" length is 8. We can see that
//given this optimal circumstance, the edit distance cannot be less than 5.
//which is 8-3 or more precisesly abs(3-8).
//if our maximum edit distance is 4, then we can discard this word
//without looking at it.
$similarity = 0;
} else {
$similarity = 1 - levenshtein($termRest, $target) / min($termRestLength, strlen($target));
}
if ($similarity > $this->_minimumSimilarity) {
$this->_matches[] = $index->currentTerm();
$this->_termKeys[] = $index->currentTerm()->key();
$this->_scores[] = ($similarity - $this->_minimumSimilarity) * $scaleFactor;
if ($maxTerms != 0 && count($this->_matches) > $maxTerms) {
throw new Lucene\Exception('Terms per query limit is reached.');
}
}
$index->nextTerm();
}
}
$index->closeTermsStream();
}
if (count($this->_matches) == 0) {
return new EmptyResult();
} else {
if (count($this->_matches) == 1) {
return new Term(reset($this->_matches));
} else {
$rewrittenQuery = new Boolean();
array_multisort($this->_scores, SORT_DESC, SORT_NUMERIC, $this->_termKeys, SORT_ASC, SORT_STRING, $this->_matches);
$termCount = 0;
foreach ($this->_matches as $id => $matchedTerm) {
$subquery = new Term($matchedTerm);
$subquery->setBoost($this->_scores[$id]);
$rewrittenQuery->addSubquery($subquery);
$termCount++;
if ($termCount >= self::MAX_CLAUSE_COUNT) {
break;
}
}
return $rewrittenQuery;
}
}
}
/**
* Re-write query into primitive queries in the context of specified index
*
* @param \Zend\Search\Lucene\SearchIndex $index
* @throws \Zend\Search\Lucence\Search\Exception\QueryParserException
* @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 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 QueryParserException('Fuzzy search is supported only for non-multiple word terms');
}
