moodle/search/Zend/Search/Lucene.php
2006-06-25 23:07:36 +00:00

614 lines
17 KiB
PHP

<?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
* @copyright Copyright (c) 2006 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
/** Zend_Search_Lucene_Exception */
require_once 'Zend/Search/Lucene/Exception.php';
/** Zend_Search_Lucene_Document */
require_once 'Zend/Search/Lucene/Document.php';
/** Zend_Search_Lucene_Storage_Directory */
require_once 'Zend/Search/Lucene/Storage/Directory/Filesystem.php';
/** Zend_Search_Lucene_Index_Term */
require_once 'Zend/Search/Lucene/Index/Term.php';
/** Zend_Search_Lucene_Index_TermInfo */
require_once 'Zend/Search/Lucene/Index/TermInfo.php';
/** Zend_Search_Lucene_Index_SegmentInfo */
require_once 'Zend/Search/Lucene/Index/SegmentInfo.php';
/** Zend_Search_Lucene_Index_FieldInfo */
require_once 'Zend/Search/Lucene/Index/FieldInfo.php';
/** Zend_Search_Lucene_Index_Writer */
require_once 'Zend/Search/Lucene/Index/Writer.php';
/** Zend_Search_Lucene_Search_QueryParser */
require_once 'Zend/Search/Lucene/Search/QueryParser.php';
/** Zend_Search_Lucene_Search_QueryHit */
require_once 'Zend/Search/Lucene/Search/QueryHit.php';
/** Zend_Search_Lucene_Search_Similarity */
require_once 'Zend/Search/Lucene/Search/Similarity.php';
/**
* @category Zend
* @package Zend_Search_Lucene
* @copyright Copyright (c) 2006 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
class Zend_Search_Lucene
{
/**
* File system adapter.
*
* @var Zend_Search_Lucene_Storage_Directory
*/
private $_directory = null;
/**
* File system adapter closing option
*
* @var boolean
*/
private $_closeDirOnExit = true;
/**
* Writer for this index, not instantiated unless required.
*
* @var Zend_Search_Lucene_Index_Writer
*/
private $_writer = null;
/**
* Array of Zend_Search_Lucene_Index_SegmentInfo objects for this index.
*
* @var array Zend_Search_Lucene_Index_SegmentInfo
*/
private $_segmentInfos = array();
/**
* Number of documents in this index.
*
* @var integer
*/
private $_docCount = 0;
/**
* Flag for index changes
*
* @var boolean
*/
private $_hasChanges = false;
/**
* Opens the index.
*
* IndexReader constructor needs Directory as a parameter. It should be
* a string with a path to the index folder or a Directory object.
*
* @param mixed $directory
* @throws Zend_Search_Lucene_Exception
*/
public function __construct($directory = null, $create = false)
{
if ($directory === null) {
throw new Zend_Search_Exception('No index directory specified');
}
if ($directory instanceof Zend_Search_Lucene_Storage_Directory_Filesystem) {
$this->_directory = $directory;
$this->_closeDirOnExit = false;
} else {
$this->_directory = new Zend_Search_Lucene_Storage_Directory_Filesystem($directory);
$this->_closeDirOnExit = true;
}
if ($create) {
$this->_writer = new Zend_Search_Lucene_Index_Writer($this->_directory, true);
} else {
$this->_writer = null;
}
$this->_segmentInfos = array();
$segmentsFile = $this->_directory->getFileObject('segments');
$format = $segmentsFile->readInt();
if ($format != (int)0xFFFFFFFF) {
throw new Zend_Search_Lucene_Exception('Wrong segments file format');
}
// read version
$segmentsFile->readLong();
// read counter
$segmentsFile->readInt();
$segments = $segmentsFile->readInt();
$this->_docCount = 0;
// read segmentInfos
for ($count = 0; $count < $segments; $count++) {
$segName = $segmentsFile->readString();
$segSize = $segmentsFile->readInt();
$this->_docCount += $segSize;
$this->_segmentInfos[$count] =
new Zend_Search_Lucene_Index_SegmentInfo($segName,
$segSize,
$this->_directory);
}
}
/**
* Object destructor
*/
public function __destruct()
{
$this->commit();
if ($this->_closeDirOnExit) {
$this->_directory->close();
}
}
/**
* Returns an instance of Zend_Search_Lucene_Index_Writer for the index
*
* @return Zend_Search_Lucene_Index_Writer
*/
public function getIndexWriter()
{
if (!$this->_writer instanceof Zend_Search_Lucene_Index_Writer) {
$this->_writer = new Zend_Search_Lucene_Index_Writer($this->_directory);
}
return $this->_writer;
}
/**
* Returns the Zend_Search_Lucene_Storage_Directory instance for this index.
*
* @return Zend_Search_Lucene_Storage_Directory
*/
public function getDirectory()
{
return $this->_directory;
}
/**
* Returns the total number of documents in this index.
*
* @return integer
*/
public function count()
{
return $this->_docCount;
}
/**
* Performs a query against the index and returns an array
* of Zend_Search_Lucene_Search_QueryHit objects.
* Input is a string or Zend_Search_Lucene_Search_Query.
*
* @param mixed $query
* @return array ZSearchHit
*/
public function find($query)
{
if (is_string($query)) {
$query = Zend_Search_Lucene_Search_QueryParser::parse($query);
}
if (!$query instanceof Zend_Search_Lucene_Search_Query) {
throw new Zend_Search_Lucene_Exception('Query must be a string or Zend_Search_Lucene_Search_Query object');
}
$this->commit();
$hits = array();
$scores = array();
$docNum = $this->count();
for( $count=0; $count < $docNum; $count++ ) {
$docScore = $query->score( $count, $this);
if( $docScore != 0 ) {
$hit = new Zend_Search_Lucene_Search_QueryHit($this);
$hit->id = $count;
$hit->score = $docScore;
$hits[] = $hit;
$scores[] = $docScore;
}
}
array_multisort($scores, SORT_DESC, SORT_REGULAR, $hits);
return $hits;
}
/**
* Returns a list of all unique field names that exist in this index.
*
* @param boolean $indexed
* @return array
*/
public function getFieldNames($indexed = false)
{
$result = array();
foreach( $this->_segmentInfos as $segmentInfo ) {
$result = array_merge($result, $segmentInfo->getFields($indexed));
}
return $result;
}
/**
* Returns a Zend_Search_Lucene_Document object for the document
* number $id in this index.
*
* @param integer|Zend_Search_Lucene_Search_QueryHit $id
* @return Zend_Search_Lucene_Document
*/
public function getDocument($id)
{
if ($id instanceof Zend_Search_Lucene_Search_QueryHit) {
/* @var $id Zend_Search_Lucene_Search_QueryHit */
$id = $id->id;
}
if ($id >= $this->_docCount) {
throw new Zend_Search_Lucene_Exception('Document id is out of the range.');
}
$segCount = 0;
$nextSegmentStartId = $this->_segmentInfos[ 0 ]->count();
while( $nextSegmentStartId <= $id ) {
$segCount++;
$nextSegmentStartId += $this->_segmentInfos[ $segCount ]->count();
}
$segmentStartId = $nextSegmentStartId - $this->_segmentInfos[ $segCount ]->count();
$fdxFile = $this->_segmentInfos[ $segCount ]->openCompoundFile('.fdx');
$fdxFile->seek( ($id-$segmentStartId)*8, SEEK_CUR );
$fieldValuesPosition = $fdxFile->readLong();
$fdtFile = $this->_segmentInfos[ $segCount ]->openCompoundFile('.fdt');
$fdtFile->seek( $fieldValuesPosition, SEEK_CUR );
$fieldCount = $fdtFile->readVInt();
$doc = new Zend_Search_Lucene_Document();
for( $count = 0; $count < $fieldCount; $count++ ) {
$fieldNum = $fdtFile->readVInt();
$bits = $fdtFile->readByte();
$fieldInfo = $this->_segmentInfos[ $segCount ]->getField($fieldNum);
if( !($bits & 2) ) { // Text data
$field = new Zend_Search_Lucene_Field($fieldInfo->name,
$fdtFile->readString(),
true,
$fieldInfo->isIndexed,
$bits & 1 );
} else {
$field = new Zend_Search_Lucene_Field($fieldInfo->name,
$fdtFile->readBinary(),
true,
$fieldInfo->isIndexed,
$bits & 1 );
}
$doc->addField($field);
}
return $doc;
}
/**
* Returns an array of all the documents which contain term.
*
* @param Zend_Search_Lucene_Index_Term $term
* @return array
*/
public function termDocs(Zend_Search_Lucene_Index_Term $term)
{
$result = array();
$segmentStartDocId = 0;
foreach ($this->_segmentInfos as $segInfo) {
$termInfo = $segInfo->getTermInfo($term);
if (!$termInfo instanceof Zend_Search_Lucene_Index_TermInfo) {
$segmentStartDocId += $segInfo->count();
continue;
}
$frqFile = $segInfo->openCompoundFile('.frq');
$frqFile->seek($termInfo->freqPointer,SEEK_CUR);
$docId = 0;
for( $count=0; $count < $termInfo->docFreq; $count++ ) {
$docDelta = $frqFile->readVInt();
if( $docDelta % 2 == 1 ) {
$docId += ($docDelta-1)/2;
} else {
$docId += $docDelta/2;
// read freq
$frqFile->readVInt();
}
$result[] = $segmentStartDocId + $docId;
}
$segmentStartDocId += $segInfo->count();
}
return $result;
}
/**
* Returns an array of all term positions in the documents.
* Return array structure: array( docId => array( pos1, pos2, ...), ...)
*
* @param Zend_Search_Lucene_Index_Term $term
* @return array
*/
public function termPositions(Zend_Search_Lucene_Index_Term $term)
{
$result = array();
$segmentStartDocId = 0;
foreach( $this->_segmentInfos as $segInfo ) {
$termInfo = $segInfo->getTermInfo($term);
if (!$termInfo instanceof Zend_Search_Lucene_Index_TermInfo) {
$segmentStartDocId += $segInfo->count();
continue;
}
$frqFile = $segInfo->openCompoundFile('.frq');
$frqFile->seek($termInfo->freqPointer,SEEK_CUR);
$freqs = array();
$docId = 0;
for( $count = 0; $count < $termInfo->docFreq; $count++ ) {
$docDelta = $frqFile->readVInt();
if( $docDelta % 2 == 1 ) {
$docId += ($docDelta-1)/2;
$freqs[ $docId ] = 1;
} else {
$docId += $docDelta/2;
$freqs[ $docId ] = $frqFile->readVInt();
}
}
$prxFile = $segInfo->openCompoundFile('.prx');
$prxFile->seek($termInfo->proxPointer,SEEK_CUR);
foreach ($freqs as $docId => $freq) {
$termPosition = 0;
$positions = array();
for ($count = 0; $count < $freq; $count++ ) {
$termPosition += $prxFile->readVInt();
$positions[] = $termPosition;
}
$result[ $segmentStartDocId + $docId ] = $positions;
}
$segmentStartDocId += $segInfo->count();
}
return $result;
}
/**
* Returns the number of documents in this index containing the $term.
*
* @param Zend_Search_Lucene_Index_Term $term
* @return integer
*/
public function docFreq(Zend_Search_Lucene_Index_Term $term)
{
$result = 0;
foreach ($this->_segmentInfos as $segInfo) {
$termInfo = $segInfo->getTermInfo($term);
if ($termInfo !== null) {
$result += $termInfo->docFreq;
}
}
return $result;
}
/**
* Retrive similarity used by index reader
*
* @return Zend_Search_Lucene_Search_Similarity
*/
public function getSimilarity()
{
return Zend_Search_Lucene_Search_Similarity::getDefault();
}
/**
* Returns a normalization factor for "field, document" pair.
*
* @param integer $id
* @param string $fieldName
* @return Zend_Search_Lucene_Document
*/
public function norm( $id, $fieldName )
{
if ($id >= $this->_docCount) {
return null;
}
$segmentStartId = 0;
foreach ($this->_segmentInfos as $segInfo) {
if ($segmentStartId + $segInfo->count() > $id) {
break;
}
$segmentStartId += $segInfo->count();
}
if ($segInfo->isDeleted($id - $segmentStartId)) {
return 0;
}
return $segInfo->norm($id - $segmentStartId, $fieldName);
}
/**
* Returns true if any documents have been deleted from this index.
*
* @return boolean
*/
public function hasDeletions()
{
foreach ($this->_segmentInfos as $segmentInfo) {
if ($segmentInfo->hasDeletions()) {
return true;
}
}
return false;
}
/**
* Deletes a document from the index.
* $id is an internal document id
*
* @param integer|Zend_Search_Lucene_Search_QueryHit $id
* @throws Zend_Search_Lucene_Exception
*/
public function delete($id)
{
if ($id instanceof Zend_Search_Lucene_Search_QueryHit) {
/* @var $id Zend_Search_Lucene_Search_QueryHit */
$id = $id->id;
}
if ($id >= $this->_docCount) {
throw new Zend_Search_Lucene_Exception('Document id is out of the range.');
}
$segCount = 0;
$nextSegmentStartId = $this->_segmentInfos[ 0 ]->count();
while( $nextSegmentStartId <= $id ) {
$segCount++;
$nextSegmentStartId += $this->_segmentInfos[ $segCount ]->count();
}
$this->_hasChanges = true;
$segmentStartId = $nextSegmentStartId - $this->_segmentInfos[ $segCount ]->count();
$this->_segmentInfos[ $segCount ]->delete($id - $segmentStartId);
}
/**
* Adds a document to this index.
*
* @param Zend_Search_Lucene_Document $document
*/
public function addDocument(Zend_Search_Lucene_Document $document)
{
if (!$this->_writer instanceof Zend_Search_Lucene_Index_Writer) {
$this->_writer = new Zend_Search_Lucene_Index_Writer($this->_directory);
}
$this->_writer->addDocument($document);
}
/**
* Commit changes resulting from delete() or undeleteAll() operations.
*
* @todo delete() and undeleteAll processing.
*/
public function commit()
{
if ($this->_hasChanges) {
foreach ($this->_segmentInfos as $segInfo) {
$segInfo->writeChanges();
}
$this->_hasChanges = false;
}
if ($this->_writer !== null) {
foreach ($this->_writer->commit() as $segmentName => $segmentInfo) {
if ($segmentInfo !== null) {
$this->_segmentInfos[] = $segmentInfo;
$this->_docCount += $segmentInfo->count();
} else {
foreach ($this->_segmentInfos as $segId => $segInfo) {
if ($segInfo->getName() == $segmentName) {
unset($this->_segmentInfos[$segId]);
}
}
}
}
}
}
/*************************************************************************
@todo UNIMPLEMENTED
*************************************************************************/
/**
* Returns an array of all terms in this index.
*
* @todo Implementation
* @return array
*/
public function terms()
{
return array();
}
/**
* Undeletes all documents currently marked as deleted in this index.
*
* @todo Implementation
*/
public function undeleteAll()
{}
}