/**
  * Get name for new segment
  *
  * @return string
  */
 private function _newSegmentName()
 {
     Zend_Search_Lucene_LockManager::obtainWriteLock($this->_directory);
     $generation = Zend_Search_Lucene::getActualGeneration($this->_directory);
     $segmentsFile = $this->_directory->getFileObject(Zend_Search_Lucene::getSegmentFileName($generation), false);
     $segmentsFile->seek(12);
     // 12 = 4 (int, file format marker) + 8 (long, index version)
     $segmentNameCounter = $segmentsFile->readInt();
     $segmentsFile->seek(12);
     // 12 = 4 (int, file format marker) + 8 (long, index version)
     $segmentsFile->writeInt($segmentNameCounter + 1);
     // Flash output to guarantee that wrong value will not be loaded between unlock and
     // return (which calls $segmentsFile destructor)
     $segmentsFile->flush();
     Zend_Search_Lucene_LockManager::releaseWriteLock($this->_directory);
     return '_' . base_convert($segmentNameCounter, 10, 36);
 }

 private function _close()
 {
     if ($this->_closed) {
         // index is already closed and resources are cleaned up
         return;
     }
     $this->commit();
     // Release "under processing" flag
     Zend_Search_Lucene_LockManager::releaseReadLock($this->_directory);
     if ($this->_closeDirOnExit) {
         $this->_directory->close();
     }
     $this->_directory = null;
     $this->_writer = null;
     $this->_segmentInfos = null;
     $this->_closed = true;
 }

 /**
  * Оптимизация индекса
  */
 public function optimize()
 {
     $zsl = $this->get_index();
     $zsl->optimize();
     // ВНИМАНИЕ!!!
     // Код, который следует далее, зависит от версии формата индекса Lucene
     // и может перестать работать и/или приводить к возникновению ошибок
     // в будущем при изменении формата, используемого Zend_Search_Lucene!
     // После некорректного завершения переиндексирования могут остаться "лишние"
     // файлы: устроим чистку...
     try {
         $path = $this->get_index_path();
         //$directory = $zsl->getDirectory();
         $directory = new Zend_Search_Lucene_Storage_Directory_Filesystem($path);
         Zend_Search_Lucene_LockManager::obtainWriteLock($directory);
         $generation = Zend_Search_Lucene::getActualGeneration($directory);
         $files_to_keep = array("segments.gen", Zend_Search_Lucene_LockManager::WRITE_LOCK_FILE, Zend_Search_Lucene_LockManager::READ_LOCK_FILE, Zend_Search_Lucene_LockManager::READ_LOCK_PROCESSING_LOCK_FILE, Zend_Search_Lucene_LockManager::OPTIMIZATION_LOCK_FILE);
         if ($generation > 0) {
             $segments_file_name = Zend_Search_Lucene::getSegmentFileName($generation);
             $files_to_keep[] = $segments_file_name;
             $segments_file = $directory->getFileObject($segments_file_name);
             // после оптимизации должен остаться только один сегмент
             // найдём имя этого сегмента
             $segments_file->seek(16);
             // 4 (int, file format marker) + 8 (long, index version) + 4 (int, segment name counter)
             $seg_count = $segments_file->readInt();
             if ($seg_count == 1) {
                 $seg_name = $segments_file->readString();
                 $files_to_keep[] = "{$seg_name}.cfs";
                 $files_to_keep[] = "{$seg_name}.sti";
                 if ($seg_name && chdir($path)) {
                     $files_to_delete = array_diff(glob("*"), $files_to_keep);
                     foreach ($files_to_delete as $f) {
                         unlink($f);
                     }
                 }
             }
         }
     } catch (Exception $e) {
         // something went south, probably it was impossible to get the write lock
         // or read some file
         // trigger_error(get_class($e) . ": {$e->getMessage()}", E_USER_WARNING);
     }
     Zend_Search_Lucene_LockManager::releaseWriteLock($directory);
 }

 /**
  * Write changes if it's necessary.
  */
 public function writeChanges()
 {
     if (!$this->_deletedDirty) {
         return;
     }
     if (extension_loaded('bitset')) {
         $delBytes = $this->_deleted;
         $bitCount = count(bitset_to_array($delBytes));
     } else {
         $byteCount = floor($this->_docCount / 8) + 1;
         $delBytes = str_repeat(chr(0), $byteCount);
         for ($count = 0; $count < $byteCount; $count++) {
             $byte = 0;
             for ($bit = 0; $bit < 8; $bit++) {
                 if (isset($this->_deleted[$count * 8 + $bit])) {
                     $byte |= 1 << $bit;
                 }
             }
             $delBytes[$count] = chr($byte);
         }
         $bitCount = count($this->_deleted);
     }
     // Get new generation number
     Zend_Search_Lucene_LockManager::obtainWriteLock($this->_directory);
     $delFileList = array();
     foreach ($this->_directory->fileList() as $file) {
         if ($file == $this->_name . '.del') {
             // Matches <segment_name>.del file name
             $delFileList[] = 0;
         } else {
             if (preg_match('/^' . $this->_name . '_([a-zA-Z0-9]+)\\.del$/i', $file, $matches)) {
                 // Matches <segment_name>_NNN.del file names
                 $delFileList[] = (int) base_convert($matches[1], 36, 10);
             }
         }
     }
     if (count($delFileList) == 0) {
         // There is no deletions file for current segment in the directory
         // Set detetions file generation number to 1
         $this->_delGen = 1;
     } else {
         // There are some deletions files for current segment in the directory
         // Set detetions file generation number to the highest + 1
         $this->_delGen = max($delFileList) + 1;
     }
     $delFile = $this->_directory->createFile($this->_name . '_' . base_convert($this->_delGen, 10, 36) . '.del');
     Zend_Search_Lucene_LockManager::releaseWriteLock($this->_directory);
     $delFile->writeInt($this->_docCount);
     $delFile->writeInt($bitCount);
     $delFile->writeBytes($delBytes);
     $this->_deletedDirty = false;
 }