/**
* Return the default Similarity implementation used by indexing and search
* code.
*
* @return ZSearchSimilarity
*/
public static function getDefault()
{
if (!self::$_defaultImpl instanceof ZSearchSimilarity) {
self::$_defaultImpl = new ZSearchDefaultSimilarity();
}
return self::$_defaultImpl;
}
/**
* Retrive similarity used by index reader
*
* @return ZSearchSimilarity
*/
public function getSimilarity()
{
return ZSearchSimilarity::getDefault();
}
/**
* Returns normalization factor for specified documents
*
* @param integer $id
* @param string $fieldName
* @return string
*/
public function norm($id, $fieldName)
{
$fieldNum = $this->getFieldNum($fieldName);
if (!$this->_fields[$fieldNum]->isIndexed) {
return null;
}
if (!isset($this->_norms[$fieldNum])) {
$fFile = $this->openCompoundFile('.f' . $fieldNum);
$this->_norms[$fieldNum] = $fFile->readBytes($this->_docCount);
}
return ZSearchSimilarity::decodeNorm(ord($this->_norms[$fieldNum][$id]));
}
