/**
* Calculate result vector for non Conjunction query
* (like '+something -another')
*
* @param ZSearch $reader
*/
private function _calculateNonConjunctionResult($reader)
{
if (extension_loaded('bitset')) {
$required = null;
$neither = bitset_empty();
$prohibited = bitset_empty();
foreach ($this->_terms as $termId => $term) {
$termDocs = bitset_from_array($reader->termDocs($term));
if ($this->_signs[$termId] === true) {
// required
if ($required !== null) {
$required = bitset_intersection($required, $termDocs);
} else {
$required = $termDocs;
}
} elseif ($this->_signs[$termId] === false) {
// prohibited
$prohibited = bitset_union($prohibited, $termDocs);
} else {
// neither required, nor prohibited
$neither = bitset_union($neither, $termDocs);
}
$this->_termsPositions[$termId] = $reader->termPositions($term);
}
if ($required === null) {
$required = $neither;
}
$this->_resVector = bitset_intersection($required, bitset_invert($prohibited, $reader->count()));
} else {
$required = null;
$neither = array();
$prohibited = array();
foreach ($this->_terms as $termId => $term) {
$termDocs = array_flip($reader->termDocs($term));
if ($this->_signs[$termId] === true) {
// required
if ($required !== null) {
// substitute for bitset_intersection
foreach ($required as $key => $value) {
if (!isset($termDocs[$key])) {
unset($required[$key]);
}
}
} else {
$required = $termDocs;
}
} elseif ($this->_signs[$termId] === false) {
// prohibited
// substitute for bitset_union
foreach ($termDocs as $key => $value) {
$prohibited[$key] = $value;
}
} else {
// neither required, nor prohibited
// substitute for bitset_union
foreach ($termDocs as $key => $value) {
$neither[$key] = $value;
}
}
$this->_termsPositions[$termId] = $reader->termPositions($term);
}
if ($required === null) {
$required = $neither;
}
foreach ($required as $key => $value) {
if (isset($prohibited[$key])) {
unset($required[$key]);
}
}
$this->_resVector = $required;
}
}
/**
* Computes a score factor for a simple term or a phrase.
*
* The default implementation is:
* return idfFreq(searcher.docFreq(term), searcher.maxDoc());
*
* input - the term in question or array of terms
* reader - reader the document collection being searched
* Returns a score factor for the term
*
* @param mixed $input
* @param ZSearch $reader
* @return a score factor for the term
*/
public function idf($input, $reader)
{
if (!is_array($input)) {
return $this->idfFreq($reader->docFreq($input), $reader->count());
} else {
$idf = 0.0;
foreach ($input as $term) {
$idf += $this->idfFreq($reader->docFreq($term), $reader->count());
}
return $idf;
}
}
