/common/libraries/plugin/phpexcel/PHPExcel/Shared/OLE/ChainedBlockStream.php

<?php

/**
 * PHPExcel
 *
 * Copyright (C) 2006 - 2011 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_Shared_OLE
 * @copyright  Copyright (c) 2006 - 2007 Christian Schmidt
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 * @version 1.7.6, 2011-02-27
 */



/**
 * PHPExcel_Shared_OLE_ChainedBlockStream
 *
 * Stream wrapper for reading data stored in an OLE file. Implements methods
 * for PHP's stream_wrapper_register(). For creating streams using this
 * wrapper, use PHPExcel_Shared_OLE_PPS_File::getStream().
 *
 * @category   PHPExcel
 * @package    PHPExcel_Shared_OLE
 */

class PHPExcel_Shared_OLE_ChainedBlockStream

{

    /**
     * The OLE container of the file that is being read.
     * @var OLE
     */

    public $ole;

    

    /**
     * Parameters specified by fopen().
     * @var array
     */

    public $params;

    

    /**
     * The binary data of the file.
     * @var  string
     */

    public $data;

    

    /**
     * The file pointer.
     * @var  int  byte offset
     */

    public $pos;



    /**
     * Implements support for fopen().
     * For creating streams using this wrapper, use OLE_PPS_File::getStream().
     * @param  string  resource name including scheme, e.g.
     * ole-chainedblockstream://oleInstanceId=1
     * @param  string  only "r" is supported
     * @param  int     mask of STREAM_REPORT_ERRORS and STREAM_USE_PATH
     * @param  string  absolute path of the opened stream (out parameter)
     * @return bool    true on success
     */

    public function stream_open($path, $mode, $options, &$openedPath)

    {

        if ($mode != 'r')

        {

            if ($options & STREAM_REPORT_ERRORS)

            {

                trigger_error('Only reading is supported', E_USER_WARNING);

            }

            return false;

        }

        

        // 25 is length of "ole-chainedblockstream://"
        parse_str(substr($path, 25), $this->params);

        if (! isset($this->params['oleInstanceId'], $this->params['blockId'], $GLOBALS['_OLE_INSTANCES'][$this->params['oleInstanceId']]))

        {

            

            if ($options & STREAM_REPORT_ERRORS)

            {

                trigger_error('OLE stream not found', E_USER_WARNING);

            }

            return false;

        }

        $this->ole = $GLOBALS['_OLE_INSTANCES'][$this->params['oleInstanceId']];

        

        $blockId = $this->params['blockId'];

        $this->data = '';

        if (isset($this->params['size']) && $this->params['size'] < $this->ole->bigBlockThreshold && $blockId != $this->ole->root->_StartBlock)

        {

            

            // Block id refers to small blocks
            $rootPos = $this->ole->_getBlockOffset($this->ole->root->_StartBlock);

            while ($blockId != - 2)

            {

                $pos = $rootPos + $blockId * $this->ole->bigBlockSize;

                $blockId = $this->ole->sbat[$blockId];

                fseek($this->ole->_file_handle, $pos);

                $this->data .= fread($this->ole->_file_handle, $this->ole->bigBlockSize);

            }

        }

        else

        {

            // Block id refers to big blocks
            while ($blockId != - 2)

            {

                $pos = $this->ole->_getBlockOffset($blockId);

                fseek($this->ole->_file_handle, $pos);

                $this->data .= fread($this->ole->_file_handle, $this->ole->bigBlockSize);

                $blockId = $this->ole->bbat[$blockId];

            }

        }

        if (isset($this->params['size']))

        {

            $this->data = substr($this->data, 0, $this->params['size']);

        }

        

        if ($options & STREAM_USE_PATH)

        {

            $openedPath = $path;

        }

        

        return true;

    }



    /**
     * Implements support for fclose().
     * @return  string
     */

    public function stream_close()

    {

        $this->ole = null;

        unset($GLOBALS['_OLE_INSTANCES']);

    }



    /**
     * Implements support for fread(), fgets() etc.
     * @param   int  maximum number of bytes to read
     * @return  string
     */

    public function stream_read($count)

    {

        if ($this->stream_eof())

        {

            return false;

        }

        $s = substr($this->data, $this->pos, $count);

        $this->pos += $count;

        return $s;

    }



    /**
     * Implements support for feof().
     * @return  bool  TRUE if the file pointer is at EOF; otherwise FALSE
     */

    public function stream_eof()

    {

        $eof = $this->pos >= strlen($this->data);

        // Workaround for bug in PHP 5.0.x: http://bugs.php.net/27508
        if (version_compare(PHP_VERSION, '5.0', '>=') && version_compare(PHP_VERSION, '5.1', '<'))

        {

            

            $eof = ! $eof;

        }

        return $eof;

    }



    /**
     * Returns the position of the file pointer, i.e. its offset into the file
     * stream. Implements support for ftell().
     * @return  int
     */

    public function stream_tell()

    {

        return $this->pos;

    }



    /**
     * Implements support for fseek().
     * @param   int  byte offset
     * @param   int  SEEK_SET, SEEK_CUR or SEEK_END
     * @return  bool
     */

    public function stream_seek($offset, $whence)

    {

        if ($whence == SEEK_SET && $offset >= 0)

        {

            $this->pos = $offset;

        }

        elseif ($whence == SEEK_CUR && - $offset <= $this->pos)

        {

            $this->pos += $offset;

        }

        elseif ($whence == SEEK_END && - $offset <= sizeof($this->data))

        {

            $this->pos = strlen($this->data) + $offset;

        }

        else

        {

            return false;

        }

        return true;

    }



    /**
     * Implements support for fstat(). Currently the only supported field is
     * "size".
     * @return  array
     */

    public function stream_stat()

    {

        return array('size' => strlen($this->data));

    }



    // Methods used by stream_wrapper_register() that are not implemented:
// bool stream_flush ( void )
// int stream_write ( string data )
// bool rename ( string path_from, string path_to )
// bool mkdir ( string path, int mode, int options )
// bool rmdir ( string path, int options )
// bool dir_opendir ( string path, int options )
// array url_stat ( string path, int flags )
// string dir_readdir ( void )
// bool dir_rewinddir ( void )
// bool dir_closedir ( void )
}