File size: 7.83Kb
<?php
/**
* Zend Framework (http://framework.zend.com/)
*
* @link http://github.com/zendframework/zf2 for the canonical source repository
* @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
* @package Zend_Search
*/
namespace ZendSearch\Lucene\Index;
use ZendSearch\Lucene;
use ZendSearch\Lucene\Document;
use ZendSearch\Lucene\Exception\RuntimeException;
use ZendSearch\Lucene\Storage\Directory;
/**
* @category Zend
* @package Zend_Search_Lucene
* @subpackage Index
*/
class SegmentMerger
{
/**
* Target segment writer
*
* @var \ZendSearch\Lucene\Index\SegmentWriter\StreamWriter
*/
private $_writer;
/**
* Number of docs in a new segment
*
* @var integer
*/
private $_docCount;
/**
* A set of segments to be merged
*
* @var array|\ZendSearch\Lucene\Index\SegmentInfo
*/
private $_segmentInfos = array();
/**
* Flag to signal, that merge is already done
*
* @var boolean
*/
private $_mergeDone = false;
/**
* Field map
* [<segment_name>][<field_number>] => <target_field_number>
*
* @var array
*/
private $_fieldsMap = array();
/**
* Object constructor.
*
* Creates new segment merger with $directory as target to merge segments into
* and $name as a name of new segment
*
* @param \ZendSearch\Lucene\Storage\Directory\DirectoryInterface $directory
* @param string $name
*/
public function __construct(Directory\DirectoryInterface $directory, $name)
{
/** \ZendSearch\Lucene\Index\SegmentWriter\StreamWriter */
$this->_writer = new SegmentWriter\StreamWriter($directory, $name);
}
/**
* Add segmnet to a collection of segments to be merged
*
* @param \ZendSearch\Lucene\Index\SegmentInfo $segment
*/
public function addSource(SegmentInfo $segmentInfo)
{
$this->_segmentInfos[$segmentInfo->getName()] = $segmentInfo;
}
/**
* Do merge.
*
* Returns number of documents in newly created segment
*
* @return \ZendSearch\Lucene\Index\SegmentInfo
* @throws \ZendSearch\Lucene\Exception\RuntimeException
*/
public function merge()
{
if ($this->_mergeDone) {
throw new RuntimeException('Merge is already done.');
}
if (count($this->_segmentInfos) < 1) {
throw new RuntimeException('Wrong number of segments to be merged ('
. count($this->_segmentInfos)
. ').');
}
$this->_mergeFields();
$this->_mergeNorms();
$this->_mergeStoredFields();
$this->_mergeTerms();
$this->_mergeDone = true;
return $this->_writer->close();
}
/**
* Merge fields information
*/
private function _mergeFields()
{
foreach ($this->_segmentInfos as $segName => $segmentInfo) {
foreach ($segmentInfo->getFieldInfos() as $fieldInfo) {
$this->_fieldsMap[$segName][$fieldInfo->number] = $this->_writer->addFieldInfo($fieldInfo);
}
}
}
/**
* Merge field's normalization factors
*/
private function _mergeNorms()
{
foreach ($this->_writer->getFieldInfos() as $fieldInfo) {
if ($fieldInfo->isIndexed) {
foreach ($this->_segmentInfos as $segName => $segmentInfo) {
if ($segmentInfo->hasDeletions()) {
$srcNorm = $segmentInfo->normVector($fieldInfo->name);
$norm = '';
$docs = $segmentInfo->count();
for ($count = 0; $count < $docs; $count++) {
if (!$segmentInfo->isDeleted($count)) {
$norm .= $srcNorm[$count];
}
}
$this->_writer->addNorm($fieldInfo->name, $norm);
} else {
$this->_writer->addNorm($fieldInfo->name, $segmentInfo->normVector($fieldInfo->name));
}
}
}
}
}
/**
* Merge fields information
*/
private function _mergeStoredFields()
{
$this->_docCount = 0;
foreach ($this->_segmentInfos as $segName => $segmentInfo) {
$fdtFile = $segmentInfo->openCompoundFile('.fdt');
for ($count = 0; $count < $segmentInfo->count(); $count++) {
$fieldCount = $fdtFile->readVInt();
$storedFields = array();
for ($count2 = 0; $count2 < $fieldCount; $count2++) {
$fieldNum = $fdtFile->readVInt();
$bits = $fdtFile->readByte();
$fieldInfo = $segmentInfo->getField($fieldNum);
if (!($bits & 2)) { // Text data
$storedFields[] =
new Document\Field($fieldInfo->name,
$fdtFile->readString(),
'UTF-8',
true,
$fieldInfo->isIndexed,
$bits & 1 );
} else { // Binary data
$storedFields[] =
new Document\Field($fieldInfo->name,
$fdtFile->readBinary(),
'',
true,
$fieldInfo->isIndexed,
$bits & 1,
true);
}
}
if (!$segmentInfo->isDeleted($count)) {
$this->_docCount++;
$this->_writer->addStoredFields($storedFields);
}
}
}
}
/**
* Merge fields information
*/
private function _mergeTerms()
{
$segmentInfoQueue = new TermsPriorityQueue();
$segmentStartId = 0;
foreach ($this->_segmentInfos as $segName => $segmentInfo) {
$segmentStartId = $segmentInfo->resetTermsStream($segmentStartId, SegmentInfo::SM_MERGE_INFO);
// Skip "empty" segments
if ($segmentInfo->currentTerm() !== null) {
$segmentInfoQueue->put($segmentInfo);
}
}
$this->_writer->initializeDictionaryFiles();
$termDocs = array();
while (($segmentInfo = $segmentInfoQueue->pop()) !== null) {
// Merge positions array
$termDocs += $segmentInfo->currentTermPositions();
if ($segmentInfoQueue->top() === null ||
$segmentInfoQueue->top()->currentTerm()->key() !=
$segmentInfo->currentTerm()->key()) {
// We got new term
ksort($termDocs, SORT_NUMERIC);
// Add term if it's contained in any document
if (count($termDocs) > 0) {
$this->_writer->addTerm($segmentInfo->currentTerm(), $termDocs);
}
$termDocs = array();
}
$segmentInfo->nextTerm();
// check, if segment dictionary is finished
if ($segmentInfo->currentTerm() !== null) {
// Put segment back into the priority queue
$segmentInfoQueue->put($segmentInfo);
}
}
$this->_writer->closeDictionaryFiles();
}
}