/common/libraries/plugin/phpexcel/PHPExcel/Shared/OLERead.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
 * @copyright  Copyright (c) 2006 - 2011 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 * @version    1.7.6, 2011-02-27
 */



define('IDENTIFIER_OLE', pack('CCCCCCCC', 0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1, 0x1a, 0xe1));



class PHPExcel_Shared_OLERead

{

    private $data = '';

    

    // OLE identifier
    const IDENTIFIER_OLE = IDENTIFIER_OLE;

    

    // Size of a sector = 512 bytes
    const BIG_BLOCK_SIZE = 0x200;

    

    // Size of a short sector = 64 bytes
    const SMALL_BLOCK_SIZE = 0x40;

    

    // Size of a directory entry always = 128 bytes
    const PROPERTY_STORAGE_BLOCK_SIZE = 0x80;

    

    // Minimum size of a standard stream = 4096 bytes, streams smaller than this are stored as short streams
    const SMALL_BLOCK_THRESHOLD = 0x1000;

    

    // header offsets
    const NUM_BIG_BLOCK_DEPOT_BLOCKS_POS = 0x2c;

    const ROOT_START_BLOCK_POS = 0x30;

    const SMALL_BLOCK_DEPOT_BLOCK_POS = 0x3c;

    const EXTENSION_BLOCK_POS = 0x44;

    const NUM_EXTENSION_BLOCK_POS = 0x48;

    const BIG_BLOCK_DEPOT_BLOCKS_POS = 0x4c;

    

    // property storage offsets (directory offsets)
    const SIZE_OF_NAME_POS = 0x40;

    const TYPE_POS = 0x42;

    const START_BLOCK_POS = 0x74;

    const SIZE_POS = 0x78;

    

    public $wrkbook = null;

    public $summaryInformation = null;

    public $documentSummaryInformation = null;



    /**
     * Read the file
     *
     * @param $sFileName string Filename
     * @throws Exception
     */

    public function read($sFileName)

    {

        // Check if file exists and is readable
        if (! is_readable($sFileName))

        {

            throw new Exception("Could not open " . $sFileName . " for reading! File does not exist, or it is not readable.");

        }

        

        // Get the file data
        $this->data = file_get_contents($sFileName);

        

        // Check OLE identifier
        if (substr($this->data, 0, 8) != self :: IDENTIFIER_OLE)

        {

            throw new Exception('The filename ' . $sFileName . ' is not recognised as an OLE file');

        }

        

        // Total number of sectors used for the SAT
        $this->numBigBlockDepotBlocks = self :: _GetInt4d($this->data, self :: NUM_BIG_BLOCK_DEPOT_BLOCKS_POS);

        

        // SecID of the first sector of the directory stream
        $this->rootStartBlock = self :: _GetInt4d($this->data, self :: ROOT_START_BLOCK_POS);

        

        // SecID of the first sector of the SSAT (or -2 if not extant)
        $this->sbdStartBlock = self :: _GetInt4d($this->data, self :: SMALL_BLOCK_DEPOT_BLOCK_POS);

        

        // SecID of the first sector of the MSAT (or -2 if no additional sectors are used)
        $this->extensionBlock = self :: _GetInt4d($this->data, self :: EXTENSION_BLOCK_POS);

        

        // Total number of sectors used by MSAT
        $this->numExtensionBlocks = self :: _GetInt4d($this->data, self :: NUM_EXTENSION_BLOCK_POS);

        

        $bigBlockDepotBlocks = array();

        $pos = self :: BIG_BLOCK_DEPOT_BLOCKS_POS;

        

        $bbdBlocks = $this->numBigBlockDepotBlocks;

        

        if ($this->numExtensionBlocks != 0)

        {

            $bbdBlocks = (self :: BIG_BLOCK_SIZE - self :: BIG_BLOCK_DEPOT_BLOCKS_POS) / 4;

        }

        

        for($i = 0; $i < $bbdBlocks; ++ $i)

        {

            $bigBlockDepotBlocks[$i] = self :: _GetInt4d($this->data, $pos);

            $pos += 4;

        }

        

        for($j = 0; $j < $this->numExtensionBlocks; ++ $j)

        {

            $pos = ($this->extensionBlock + 1) * self :: BIG_BLOCK_SIZE;

            $blocksToRead = min($this->numBigBlockDepotBlocks - $bbdBlocks, self :: BIG_BLOCK_SIZE / 4 - 1);

            

            for($i = $bbdBlocks; $i < $bbdBlocks + $blocksToRead; ++ $i)

            {

                $bigBlockDepotBlocks[$i] = self :: _GetInt4d($this->data, $pos);

                $pos += 4;

            }

            

            $bbdBlocks += $blocksToRead;

            if ($bbdBlocks < $this->numBigBlockDepotBlocks)

            {

                $this->extensionBlock = self :: _GetInt4d($this->data, $pos);

            }

        }

        

        $pos = $index = 0;

        $this->bigBlockChain = array();

        

        $bbs = self :: BIG_BLOCK_SIZE / 4;

        for($i = 0; $i < $this->numBigBlockDepotBlocks; ++ $i)

        {

            $pos = ($bigBlockDepotBlocks[$i] + 1) * self :: BIG_BLOCK_SIZE;

            

            for($j = 0; $j < $bbs; ++ $j)

            {

                $this->bigBlockChain[$index] = self :: _GetInt4d($this->data, $pos);

                $pos += 4;

                ++ $index;

            }

        }

        

        $pos = $index = 0;

        $sbdBlock = $this->sbdStartBlock;

        $this->smallBlockChain = array();

        

        while ($sbdBlock != - 2)

        {

            $pos = ($sbdBlock + 1) * self :: BIG_BLOCK_SIZE;

            

            for($j = 0; $j < $bbs; ++ $j)

            {

                $this->smallBlockChain[$index] = self :: _GetInt4d($this->data, $pos);

                $pos += 4;

                ++ $index;

            }

            

            $sbdBlock = $this->bigBlockChain[$sbdBlock];

        }

        

        // read the directory stream
        $block = $this->rootStartBlock;

        $this->entry = $this->_readData($block);

        

        $this->_readPropertySets();

    }



    /**
     * Extract binary stream data
     *
     * @return string
     */

    public function getStream($stream)

    {

        if (is_null($stream))

        {

            return null;

        }

        

        $streamData = '';

        

        if ($this->props[$stream]['size'] < self :: SMALL_BLOCK_THRESHOLD)

        {

            $rootdata = $this->_readData($this->props[$this->rootentry]['startBlock']);

            

            $block = $this->props[$stream]['startBlock'];

            

            while ($block != - 2)

            {

                $pos = $block * self :: SMALL_BLOCK_SIZE;

                $streamData .= substr($rootdata, $pos, self :: SMALL_BLOCK_SIZE);

                

                $block = $this->smallBlockChain[$block];

            }

            

            return $streamData;

        }

        else

        {

            $numBlocks = $this->props[$stream]['size'] / self :: BIG_BLOCK_SIZE;

            if ($this->props[$stream]['size'] % self :: BIG_BLOCK_SIZE != 0)

            {

                ++ $numBlocks;

            }

            

            if ($numBlocks == 0)

                return '';

            

            $block = $this->props[$stream]['startBlock'];

            

            while ($block != - 2)

            {

                $pos = ($block + 1) * self :: BIG_BLOCK_SIZE;

                $streamData .= substr($this->data, $pos, self :: BIG_BLOCK_SIZE);

                $block = $this->bigBlockChain[$block];

            }

            

            return $streamData;

        }

    }



    /**
     * Read a standard stream (by joining sectors using information from SAT)
     *
     * @param int $bl Sector ID where the stream starts
     * @return string Data for standard stream
     */

    private function _readData($bl)

    {

        $block = $bl;

        $data = '';

        

        while ($block != - 2)

        {

            $pos = ($block + 1) * self :: BIG_BLOCK_SIZE;

            $data .= substr($this->data, $pos, self :: BIG_BLOCK_SIZE);

            $block = $this->bigBlockChain[$block];

        }

        return $data;

    }



    /**
     * Read entries in the directory stream.
     */

    private function _readPropertySets()

    {

        $offset = 0;

        

        // loop through entires, each entry is 128 bytes
        $entryLen = strlen($this->entry);

        while ($offset < $entryLen)

        {

            // entry data (128 bytes)
            $d = substr($this->entry, $offset, self :: PROPERTY_STORAGE_BLOCK_SIZE);

            

            // size in bytes of name
            $nameSize = ord($d[self :: SIZE_OF_NAME_POS]) | (ord($d[self :: SIZE_OF_NAME_POS + 1]) << 8);

            

            // type of entry
            $type = ord($d[self :: TYPE_POS]);

            

            // sectorID of first sector or short sector, if this entry refers to a stream (the case with workbook)
            // sectorID of first sector of the short-stream container stream, if this entry is root entry
            $startBlock = self :: _GetInt4d($d, self :: START_BLOCK_POS);

            

            $size = self :: _GetInt4d($d, self :: SIZE_POS);

            

            $name = str_replace("\x00", "", substr($d, 0, $nameSize));

            

            $this->props[] = array('name' => $name, 'type' => $type, 'startBlock' => $startBlock, 'size' => $size);

            

            // Workbook directory entry (BIFF5 uses Book, BIFF8 uses Workbook)
            if (($name == 'Workbook') || ($name == 'Book') || ($name == 'WORKBOOK') || ($name == 'BOOK'))

            {

                $this->wrkbook = count($this->props) - 1;

            }

            

            // Root entry
            if ($name == 'Root Entry' || $name == 'ROOT ENTRY' || $name == 'R')

            {

                $this->rootentry = count($this->props) - 1;

            }

            

            // Summary information
            if ($name == chr(5) . 'SummaryInformation')

            {

                //				echo 'Summary Information<br />';
                $this->summaryInformation = count($this->props) - 1;

            }

            

            // Additional Document Summary information
            if ($name == chr(5) . 'DocumentSummaryInformation')

            {

                //				echo 'Document Summary Information<br />';
                $this->documentSummaryInformation = count($this->props) - 1;

            }

            

            $offset += self :: PROPERTY_STORAGE_BLOCK_SIZE;

        }

    

    }



    /**
     * Read 4 bytes of data at specified position
     *
     * @param string $data
     * @param int $pos
     * @return int
     */

    private static function _GetInt4d($data, $pos)

    {

        // FIX: represent numbers correctly on 64-bit system
        // http://sourceforge.net/tracker/index.php?func=detail&aid=1487372&group_id=99160&atid=623334
        // Hacked by Andreas Rehm 2006 to ensure correct result of the <<24 block on 32 and 64bit systems
        $_or_24 = ord($data[$pos + 3]);

        if ($_or_24 >= 128)

        {

            // negative number
            $_ord_24 = - abs((256 - $_or_24) << 24);

        }

        else

        {

            $_ord_24 = ($_or_24 & 127) << 24;

        }

        return ord($data[$pos]) | (ord($data[$pos + 1]) << 8) | (ord($data[$pos + 2]) << 16) | $_ord_24;

    }



}