source: sourcecode/application/libraries/PHPExcel/CachedObjectStorage/CacheBase.php @ 1

<?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_CacheBase
 *
 * @category   PHPExcel
 * @package    PHPExcel_CachedObjectStorage
 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
abstract class PHPExcel_CachedObjectStorage_CacheBase {

        /**
         * Parent worksheet
         *
         * @var PHPExcel_Worksheet
         */
        protected $_parent;

        /**
         * The currently active Cell
         *
         * @var PHPExcel_Cell
         */
        protected $_currentObject = null;

        /**
         * Coordinate address of the currently active Cell
         *
         * @var string
         */
        protected $_currentObjectID = null;


        /**
         * Flag indicating whether the currently active Cell requires saving
         *
         * @var boolean
         */
        protected $_currentCellIsDirty = true;

        /**
         * An array of cells or cell pointers for the worksheet cells held in this cache,
         *              and indexed by their coordinate address within the worksheet
         *
         * @var array of mixed
         */
        protected $_cellCache = array();


        /**
         * Initialise this new cell collection
         *
         * @param       PHPExcel_Worksheet      $parent         The worksheet for this cell collection
         */
        public function __construct(PHPExcel_Worksheet $parent) {
                //      Set our parent worksheet.
                //      This is maintained within the cache controller to facilitate re-attaching it to PHPExcel_Cell objects when
                //              they are woken from a serialized state
                $this->_parent = $parent;
        }       //      function __construct()


        /**
         * Return the parent worksheet for this cell collection
         *
         * @return      PHPExcel_Worksheet
         */
        public function getParent()
        {
                return $this->_parent;
        }

        /**
         * Is a value set in the current PHPExcel_CachedObjectStorage_ICache for an indexed cell?
         *
         * @param       string          $pCoord         Coordinate address of the cell to check
         * @return      boolean
         */
        public function isDataSet($pCoord) {
                if ($pCoord === $this->_currentObjectID) {
                        return true;
                }
                //      Check if the requested entry exists in the cache
                return isset($this->_cellCache[$pCoord]);
        }       //      function isDataSet()


        /**
         * Move a cell object from one address to another
         *
         * @param       string          $fromAddress    Current address of the cell to move
         * @param       string          $toAddress              Destination address of the cell to move
         * @return      boolean
         */
        public function moveCell($fromAddress, $toAddress) {
                if ($fromAddress === $this->_currentObjectID) {
                        $this->_currentObjectID = $toAddress;
                }
                $this->_currentCellIsDirty = true;
                if (isset($this->_cellCache[$fromAddress])) {
                        $this->_cellCache[$toAddress] = &$this->_cellCache[$fromAddress];
                        unset($this->_cellCache[$fromAddress]);
                }

                return TRUE;
        }       //      function moveCell()


    /**
     * Add or Update a cell in cache
     *
     * @param   PHPExcel_Cell   $cell           Cell to update
         * @return      void
     * @throws  PHPExcel_Exception
     */
        public function updateCacheData(PHPExcel_Cell $cell) {
                return $this->addCacheData($cell->getCoordinate(),$cell);
        }       //      function updateCacheData()


    /**
     * Delete a cell in cache identified by coordinate address
     *
     * @param   string                  $pCoord         Coordinate address of the cell to delete
     * @throws  PHPExcel_Exception
     */
        public function deleteCacheData($pCoord) {
                if ($pCoord === $this->_currentObjectID) {
                        $this->_currentObject->detach();
                        $this->_currentObjectID = $this->_currentObject = null;
                }

                if (is_object($this->_cellCache[$pCoord])) {
                        $this->_cellCache[$pCoord]->detach();
                        unset($this->_cellCache[$pCoord]);
                }
                $this->_currentCellIsDirty = false;
        }       //      function deleteCacheData()


        /**
         * Get a list of all cell addresses currently held in cache
         *
         * @return      array of string
         */
        public function getCellList() {
                return array_keys($this->_cellCache);
        }       //      function getCellList()


        /**
         * Sort the list of all cell addresses currently held in cache by row and column
         *
         * @return      void
         */
        public function getSortedCellList() {
                $sortKeys = array();
                foreach ($this->getCellList() as $coord) {
                        sscanf($coord,'%[A-Z]%d', $column, $row);
                        $sortKeys[sprintf('%09d%3s',$row,$column)] = $coord;
                }
                ksort($sortKeys);

                return array_values($sortKeys);
        }       //      function sortCellList()



        /**
         * Get highest worksheet column and highest row that have cell records
         *
         * @return array Highest column name and highest row number
         */
        public function getHighestRowAndColumn()
        {
                // Lookup highest column and highest row
                $col = array('A' => '1A');
                $row = array(1);
                foreach ($this->getCellList() as $coord) {
                        sscanf($coord,'%[A-Z]%d', $c, $r);
                        $row[$r] = $r;
                        $col[$c] = strlen($c).$c;
                }
                if (!empty($row)) {
                        // Determine highest column and row
                        $highestRow = max($row);
                        $highestColumn = substr(max($col),1);
                }

                return array( 'row'        => $highestRow,
                                          'column' => $highestColumn
                                        );
        }


        /**
         * Return the cell address of the currently active cell object
         *
         * @return      string
         */
        public function getCurrentAddress()
        {
                return $this->_currentObjectID;
        }

        /**
         * Return the column address of the currently active cell object
         *
         * @return      string
         */
        public function getCurrentColumn()
        {
                sscanf($this->_currentObjectID, '%[A-Z]%d', $column, $row);
                return $column;
        }

        /**
         * Return the row address of the currently active cell object
         *
         * @return      string
         */
        public function getCurrentRow()
        {
                sscanf($this->_currentObjectID, '%[A-Z]%d', $column, $row);
                return $row;
        }

        /**
         * Get highest worksheet column
         *
     * @param   string     $row        Return the highest column for the specified row,
     *                                     or the highest column of any row if no row number is passed
         * @return  string     Highest column name
         */
        public function getHighestColumn($row = null)
        {
        if ($row == null) {
                $colRow = $this->getHighestRowAndColumn();
                return $colRow['column'];
        }

        $columnList = array(1);
        foreach ($this->getCellList() as $coord) {
            sscanf($coord,'%[A-Z]%d', $c, $r);
            if ($r != $row) {
                continue;
            }
            $columnList[] = PHPExcel_Cell::columnIndexFromString($c);
        }
        return PHPExcel_Cell::stringFromColumnIndex(max($columnList) - 1);
    }

        /**
         * Get highest worksheet row
         *
     * @param   string     $column     Return the highest row for the specified column,
     *                                     or the highest row of any column if no column letter is passed
         * @return  int        Highest row number
         */
        public function getHighestRow($column = null)
        {
        if ($column == null) {
                $colRow = $this->getHighestRowAndColumn();
                return $colRow['row'];
        }

        $rowList = array(0);
        foreach ($this->getCellList() as $coord) {
            sscanf($coord,'%[A-Z]%d', $c, $r);
            if ($c != $column) {
                continue;
            }
            $rowList[] = $r;
        }

        return max($rowList);
        }


        /**
         * Generate a unique ID for cache referencing
         *
         * @return string Unique Reference
         */
        protected function _getUniqueID() {
                if (function_exists('posix_getpid')) {
                        $baseUnique = posix_getpid();
                } else {
                        $baseUnique = mt_rand();
                }
                return uniqid($baseUnique,true);
        }

        /**
         * Clone the cell collection
         *
         * @param       PHPExcel_Worksheet      $parent         The new worksheet
         * @return      void
         */
        public function copyCellCollection(PHPExcel_Worksheet $parent) {
                $this->_currentCellIsDirty;
        $this->_storeData();

                $this->_parent = $parent;
                if (($this->_currentObject !== NULL) && (is_object($this->_currentObject))) {
                        $this->_currentObject->attach($this);
                }
        }       //      function copyCellCollection()


        /**
         * Identify whether the caching method is currently available
         * Some methods are dependent on the availability of certain extensions being enabled in the PHP build
         *
         * @return      boolean
         */
        public static function cacheMethodIsAvailable() {
                return true;
        }

}