function lock() does a ClearMeta and a SetMeta in a row. This involves creating 2 tmp files and 2 file renames, while one would be enough.

Patch:

• add a 3rd param to SetMeta: $clear=false
• if $clear !== false, do not unserialize $this->currentFileName
• lock calls setMeta( 'timestamp', time(), true )

      function setMeta( $key, $value, $clear=false)
      {
          $tmpFile = $this->MetaFileName . substr( md5( mt_rand() ), 0, 8 );
          if ( $clear !== false && file_exists( $this->MetaFileName ) )
          {
              $content = unserialize( eZFile::getContents( $this->MetaFileName ) );
          }
          else
          {
              $content = array();
          }
          $content[$key] = $value;
          eZFile::create( $tmpFile, false, serialize( $content) );
          eZFile::rename( $tmpFile, $this->MetaFileName );
      }