<?php

/**

 * PHPExcel

 *

 * Copyright (c) 2006 - 2014 PHPExcel

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 *

 * @category   PHPExcel

 * @package    PHPExcel_CachedObjectStorage

 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)

 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL

 * @version    1.8.0, 2014-03-02

 */





/**

 * PHPExcel_CachedObjectStorage_DiscISAM

 *

 * @category   PHPExcel

 * @package    PHPExcel_CachedObjectStorage

 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)

 */

class PHPExcel_CachedObjectStorage_DiscISAM extends PHPExcel_CachedObjectStorage_CacheBase implements PHPExcel_CachedObjectStorage_ICache {



	/**

	 * Name of the file for this cache

	 *

	 * @var string

	 */

	private $_fileName = NULL;



	/**

	 * File handle for this cache file

	 *

	 * @var resource

	 */

	private $_fileHandle = NULL;



	/**

	 * Directory/Folder where the cache file is located

	 *

	 * @var string

	 */

	private $_cacheDirectory = NULL;





    /**

     * Store cell data in cache for the current cell object if it's "dirty",

     *     and the 'nullify' the current cell object

     *

	 * @return	void

     * @throws	PHPExcel_Exception

     */

	protected function _storeData() {

		if ($this->_currentCellIsDirty && !empty($this->_currentObjectID)) {

			$this->_currentObject->detach();



			fseek($this->_fileHandle,0,SEEK_END);

			$offset = ftell($this->_fileHandle);

			fwrite($this->_fileHandle, serialize($this->_currentObject));

			$this->_cellCache[$this->_currentObjectID]	= array('ptr' => $offset,

																'sz'  => ftell($this->_fileHandle) - $offset

															   );

			$this->_currentCellIsDirty = false;

		}

		$this->_currentObjectID = $this->_currentObject = null;

	}	//	function _storeData()





    /**

     * Add or Update a cell in cache identified by coordinate address

     *

     * @param	string			$pCoord		Coordinate address of the cell to update

     * @param	PHPExcel_Cell	$cell		Cell to update

	 * @return	void

     * @throws	PHPExcel_Exception

     */

	public function addCacheData($pCoord, PHPExcel_Cell $cell) {

		if (($pCoord !== $this->_currentObjectID) && ($this->_currentObjectID !== null)) {

			$this->_storeData();

		}



		$this->_currentObjectID = $pCoord;

		$this->_currentObject = $cell;

		$this->_currentCellIsDirty = true;



		return $cell;

	}	//	function addCacheData()





    /**

     * Get cell at a specific coordinate

     *

     * @param 	string 			$pCoord		Coordinate of the cell

     * @throws 	PHPExcel_Exception

     * @return 	PHPExcel_Cell 	Cell that was found, or null if not found

     */

	public function getCacheData($pCoord) {

		if ($pCoord === $this->_currentObjectID) {

			return $this->_currentObject;

		}

		$this->_storeData();



		//	Check if the entry that has been requested actually exists

		if (!isset($this->_cellCache[$pCoord])) {

			//	Return null if requested entry doesn't exist in cache

			return null;

		}



		//	Set current entry to the requested entry

		$this->_currentObjectID = $pCoord;

		fseek($this->_fileHandle,$this->_cellCache[$pCoord]['ptr']);

		$this->_currentObject = unserialize(fread($this->_fileHandle,$this->_cellCache[$pCoord]['sz']));

        //    Re-attach this as the cell's parent

        $this->_currentObject->attach($this);



		//	Return requested entry

		return $this->_currentObject;

	}	//	function getCacheData()





	/**

	 * Get a list of all cell addresses currently held in cache

	 *

	 * @return  array of string

	 */

	public function getCellList() {

		if ($this->_currentObjectID !== null) {

			$this->_storeData();

		}



		return parent::getCellList();

	}





	/**

	 * Clone the cell collection

	 *

	 * @param	PHPExcel_Worksheet	$parent		The new worksheet

	 * @return	void

	 */

	public function copyCellCollection(PHPExcel_Worksheet $parent) {

		parent::copyCellCollection($parent);

		//	Get a new id for the new file name

		$baseUnique = $this->_getUniqueID();

		$newFileName = $this->_cacheDirectory.'/PHPExcel.'.$baseUnique.'.cache';

		//	Copy the existing cell cache file

		copy ($this->_fileName,$newFileName);

		$this->_fileName = $newFileName;

		//	Open the copied cell cache file

		$this->_fileHandle = fopen($this->_fileName,'a+');

	}	//	function copyCellCollection()





	/**

	 * Clear the cell collection and disconnect from our parent

	 *

	 * @return	void

	 */

	public function unsetWorksheetCells() {

		if(!is_null($this->_currentObject)) {

			$this->_currentObject->detach();

			$this->_currentObject = $this->_currentObjectID = null;

		}

		$this->_cellCache = array();



		//	detach ourself from the worksheet, so that it can then delete this object successfully

		$this->_parent = null;



		//	Close down the temporary cache file

		$this->__destruct();

	}	//	function unsetWorksheetCells()





	/**

	 * Initialise this new cell collection

	 *

	 * @param	PHPExcel_Worksheet	$parent		The worksheet for this cell collection

	 * @param	array of mixed		$arguments	Additional initialisation arguments

	 */

	public function __construct(PHPExcel_Worksheet $parent, $arguments) {

		$this->_cacheDirectory	= ((isset($arguments['dir'])) && ($arguments['dir'] !== NULL))

									? $arguments['dir']

									: PHPExcel_Shared_File::sys_get_temp_dir();



		parent::__construct($parent);

		if (is_null($this->_fileHandle)) {

			$baseUnique = $this->_getUniqueID();

			$this->_fileName = $this->_cacheDirectory.'/PHPExcel.'.$baseUnique.'.cache';

			$this->_fileHandle = fopen($this->_fileName,'a+');

		}

	}	//	function __construct()





	/**

	 * Destroy this cell collection

	 */

	public function __destruct() {

		if (!is_null($this->_fileHandle)) {

			fclose($this->_fileHandle);

			unlink($this->_fileName);

		}

		$this->_fileHandle = null;

	}	//	function __destruct()



}

