OLE.php

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<?php
/* vim: set expandtab tabstop=4 shiftwidth=4: */
// +----------------------------------------------------------------------+
// | PHP Version 4                                                        |
// +----------------------------------------------------------------------+
// | Copyright (c) 1997-2002 The PHP Group                                |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.02 of the PHP license,      |
// | that is bundled with this package in the file LICENSE, and is        |
// | available at through the world-wide-web at                           |
// | http://www.php.net/license/2_02.txt.                                 |
// | If you did not receive a copy of the PHP license and are unable to   |
// | obtain it through the world-wide-web, please send a note to          |
// | license@php.net so we can mail you a copy immediately.               |
// +----------------------------------------------------------------------+
// | Author: Xavier Noguer <xnoguer@php.net>                              |
// | Based on OLE::Storage_Lite by Kawai, Takanori                        |
// +----------------------------------------------------------------------+
//
// $Id: OLE.php,v 1.13 2007/03/07 14:38:25 schmidt Exp $


$GLOBALS['_OLE_INSTANCES'] = array();

class PHPExcel_Shared_OLE
{
        const OLE_PPS_TYPE_ROOT   =      5;
        const OLE_PPS_TYPE_DIR    =      1;
        const OLE_PPS_TYPE_FILE   =      2;
        const OLE_DATA_SIZE_SMALL = 0x1000;
        const OLE_LONG_INT_SIZE   =      4;
        const OLE_PPS_SIZE        =   0x80;

        public $_file_handle;

        public $_list = array();

        public $root;

        public $bbat;

        public $sbat;

        public $bigBlockSize;

        public $smallBlockSize;

        public function read($file)
        {
                $fh = fopen($file, "r");
                if (!$fh) {
                        throw new PHPExcel_Reader_Exception("Can't open file $file");
                }
                $this->_file_handle = $fh;

                $signature = fread($fh, 8);
                if ("\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1" != $signature) {
                        throw new PHPExcel_Reader_Exception("File doesn't seem to be an OLE container.");
                }
                fseek($fh, 28);
                if (fread($fh, 2) != "\xFE\xFF") {
                        // This shouldn't be a problem in practice
                        throw new PHPExcel_Reader_Exception("Only Little-Endian encoding is supported.");
                }
                // Size of blocks and short blocks in bytes
                $this->bigBlockSize = pow(2, self::_readInt2($fh));
                $this->smallBlockSize  = pow(2, self::_readInt2($fh));

                // Skip UID, revision number and version number
                fseek($fh, 44);
                // Number of blocks in Big Block Allocation Table
                $bbatBlockCount = self::_readInt4($fh);

                // Root chain 1st block
                $directoryFirstBlockId = self::_readInt4($fh);

                // Skip unused bytes
                fseek($fh, 56);
                // Streams shorter than this are stored using small blocks
                $this->bigBlockThreshold = self::_readInt4($fh);
                // Block id of first sector in Short Block Allocation Table
                $sbatFirstBlockId = self::_readInt4($fh);
                // Number of blocks in Short Block Allocation Table
                $sbbatBlockCount = self::_readInt4($fh);
                // Block id of first sector in Master Block Allocation Table
                $mbatFirstBlockId = self::_readInt4($fh);
                // Number of blocks in Master Block Allocation Table
                $mbbatBlockCount = self::_readInt4($fh);
                $this->bbat = array();

                // Remaining 4 * 109 bytes of current block is beginning of Master
                // Block Allocation Table
                $mbatBlocks = array();
                for ($i = 0; $i < 109; ++$i) {
                        $mbatBlocks[] = self::_readInt4($fh);
                }

                // Read rest of Master Block Allocation Table (if any is left)
                $pos = $this->_getBlockOffset($mbatFirstBlockId);
                for ($i = 0; $i < $mbbatBlockCount; ++$i) {
                        fseek($fh, $pos);
                        for ($j = 0; $j < $this->bigBlockSize / 4 - 1; ++$j) {
                                $mbatBlocks[] = self::_readInt4($fh);
                        }
                        // Last block id in each block points to next block
                        $pos = $this->_getBlockOffset(self::_readInt4($fh));
                }

                // Read Big Block Allocation Table according to chain specified by
                // $mbatBlocks
                for ($i = 0; $i < $bbatBlockCount; ++$i) {
                        $pos = $this->_getBlockOffset($mbatBlocks[$i]);
                        fseek($fh, $pos);
                        for ($j = 0 ; $j < $this->bigBlockSize / 4; ++$j) {
                                $this->bbat[] = self::_readInt4($fh);
                        }
                }

                // Read short block allocation table (SBAT)
                $this->sbat = array();
                $shortBlockCount = $sbbatBlockCount * $this->bigBlockSize / 4;
                $sbatFh = $this->getStream($sbatFirstBlockId);
                for ($blockId = 0; $blockId < $shortBlockCount; ++$blockId) {
                        $this->sbat[$blockId] = self::_readInt4($sbatFh);
                }
                fclose($sbatFh);

                $this->_readPpsWks($directoryFirstBlockId);

                return true;
        }

        public function _getBlockOffset($blockId)
        {
                return 512 + $blockId * $this->bigBlockSize;
        }

        public function getStream($blockIdOrPps)
        {
                static $isRegistered = false;
                if (!$isRegistered) {
                        stream_wrapper_register('ole-chainedblockstream',
                                'PHPExcel_Shared_OLE_ChainedBlockStream');
                        $isRegistered = true;
                }

                // Store current instance in global array, so that it can be accessed
                // in OLE_ChainedBlockStream::stream_open().
                // Object is removed from self::$instances in OLE_Stream::close().
                $GLOBALS['_OLE_INSTANCES'][] = $this;
                $instanceId = end(array_keys($GLOBALS['_OLE_INSTANCES']));

                $path = 'ole-chainedblockstream://oleInstanceId=' . $instanceId;
                if ($blockIdOrPps instanceof PHPExcel_Shared_OLE_PPS) {
                        $path .= '&blockId=' . $blockIdOrPps->_StartBlock;
                        $path .= '&size=' . $blockIdOrPps->Size;
                } else {
                        $path .= '&blockId=' . $blockIdOrPps;
                }
                return fopen($path, 'r');
        }

        private static function _readInt1($fh)
        {
                list(, $tmp) = unpack("c", fread($fh, 1));
                return $tmp;
        }

        private static function _readInt2($fh)
        {
                list(, $tmp) = unpack("v", fread($fh, 2));
                return $tmp;
        }

        private static function _readInt4($fh)
        {
                list(, $tmp) = unpack("V", fread($fh, 4));
                return $tmp;
        }

        public function _readPpsWks($blockId)
        {
                $fh = $this->getStream($blockId);
                for ($pos = 0; ; $pos += 128) {
                        fseek($fh, $pos, SEEK_SET);
                        $nameUtf16 = fread($fh, 64);
                        $nameLength = self::_readInt2($fh);
                        $nameUtf16 = substr($nameUtf16, 0, $nameLength - 2);
                        // Simple conversion from UTF-16LE to ISO-8859-1
                        $name = str_replace("\x00", "", $nameUtf16);
                        $type = self::_readInt1($fh);
                        switch ($type) {
                        case self::OLE_PPS_TYPE_ROOT:
                                $pps = new PHPExcel_Shared_OLE_PPS_Root(null, null, array());
                                $this->root = $pps;
                                break;
                        case self::OLE_PPS_TYPE_DIR:
                                $pps = new PHPExcel_Shared_OLE_PPS(null, null, null, null, null,
                                                                   null, null, null, null, array());
                                break;
                        case self::OLE_PPS_TYPE_FILE:
                                $pps = new PHPExcel_Shared_OLE_PPS_File($name);
                                break;
                        default:
                                continue;
                        }
                        fseek($fh, 1, SEEK_CUR);
                        $pps->Type    = $type;
                        $pps->Name    = $name;
                        $pps->PrevPps = self::_readInt4($fh);
                        $pps->NextPps = self::_readInt4($fh);
                        $pps->DirPps  = self::_readInt4($fh);
                        fseek($fh, 20, SEEK_CUR);
                        $pps->Time1st = self::OLE2LocalDate(fread($fh, 8));
                        $pps->Time2nd = self::OLE2LocalDate(fread($fh, 8));
                        $pps->_StartBlock = self::_readInt4($fh);
                        $pps->Size = self::_readInt4($fh);
                        $pps->No = count($this->_list);
                        $this->_list[] = $pps;

                        // check if the PPS tree (starting from root) is complete
                        if (isset($this->root) &&
                                $this->_ppsTreeComplete($this->root->No)) {

                                break;
                        }
                }
                fclose($fh);

                // Initialize $pps->children on directories
                foreach ($this->_list as $pps) {
                        if ($pps->Type == self::OLE_PPS_TYPE_DIR || $pps->Type == self::OLE_PPS_TYPE_ROOT) {
                                $nos = array($pps->DirPps);
                                $pps->children = array();
                                while ($nos) {
                                        $no = array_pop($nos);
                                        if ($no != -1) {
                                                $childPps = $this->_list[$no];
                                                $nos[] = $childPps->PrevPps;
                                                $nos[] = $childPps->NextPps;
                                                $pps->children[] = $childPps;
                                        }
                                }
                        }
                }

                return true;
        }

        public function _ppsTreeComplete($index)
        {
                return isset($this->_list[$index]) &&
                           ($pps = $this->_list[$index]) &&
                           ($pps->PrevPps == -1 ||
                                $this->_ppsTreeComplete($pps->PrevPps)) &&
                           ($pps->NextPps == -1 ||
                                $this->_ppsTreeComplete($pps->NextPps)) &&
                           ($pps->DirPps == -1 ||
                                $this->_ppsTreeComplete($pps->DirPps));
        }

        public function isFile($index)
        {
                if (isset($this->_list[$index])) {
                        return ($this->_list[$index]->Type == self::OLE_PPS_TYPE_FILE);
                }
                return false;
        }

        public function isRoot($index)
        {
                if (isset($this->_list[$index])) {
                        return ($this->_list[$index]->Type == self::OLE_PPS_TYPE_ROOT);
                }
                return false;
        }

        public function ppsTotal()
        {
                return count($this->_list);
        }

        public function getData($index, $position, $length)
        {
                // if position is not valid return empty string
                if (!isset($this->_list[$index]) || ($position >= $this->_list[$index]->Size) || ($position < 0)) {
                        return '';
                }
                $fh = $this->getStream($this->_list[$index]);
                $data = stream_get_contents($fh, $length, $position);
                fclose($fh);
                return $data;
        }

        public function getDataLength($index)
        {
                if (isset($this->_list[$index])) {
                        return $this->_list[$index]->Size;
                }
                return 0;
        }

        public static function Asc2Ucs($ascii)
        {
                $rawname = '';
                for ($i = 0; $i < strlen($ascii); ++$i) {
                        $rawname .= $ascii{$i} . "\x00";
                }
                return $rawname;
        }

        public static function LocalDate2OLE($date = null)
        {
                if (!isset($date)) {
                        return "\x00\x00\x00\x00\x00\x00\x00\x00";
                }

                // factor used for separating numbers into 4 bytes parts
                $factor = pow(2, 32);

                // days from 1-1-1601 until the beggining of UNIX era
                $days = 134774;
                // calculate seconds
                $big_date = $days*24*3600 + gmmktime(date("H",$date),date("i",$date),date("s",$date),
                                                                                         date("m",$date),date("d",$date),date("Y",$date));
                // multiply just to make MS happy
                $big_date *= 10000000;

                $high_part = floor($big_date / $factor);
                // lower 4 bytes
                $low_part = floor((($big_date / $factor) - $high_part) * $factor);

                // Make HEX string
                $res = '';

                for ($i = 0; $i < 4; ++$i) {
                        $hex = $low_part % 0x100;
                        $res .= pack('c', $hex);
                        $low_part /= 0x100;
                }
                for ($i = 0; $i < 4; ++$i) {
                        $hex = $high_part % 0x100;
                        $res .= pack('c', $hex);
                        $high_part /= 0x100;
                }
                return $res;
        }

        public static function OLE2LocalDate($string)
        {
                if (strlen($string) != 8) {
                        return new PEAR_Error("Expecting 8 byte string");
                }

                // factor used for separating numbers into 4 bytes parts
                $factor = pow(2,32);
                list(, $high_part) = unpack('V', substr($string, 4, 4));
                list(, $low_part) = unpack('V', substr($string, 0, 4));

                $big_date = ($high_part * $factor) + $low_part;
                // translate to seconds
                $big_date /= 10000000;

                // days from 1-1-1601 until the beggining of UNIX era
                $days = 134774;

                // translate to seconds from beggining of UNIX era
                $big_date -= $days * 24 * 3600;
                return floor($big_date);
        }
}