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<?php
namespace PhpOffice\PhpSpreadsheet\Writer\Xls;
use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
// Original file header of PEAR::Spreadsheet_Excel_Writer_BIFFwriter (used as the base for this class):
// -----------------------------------------------------------------------------------------
// * Module written/ported by Xavier Noguer <xnoguer@rezebra.com>
// *
// * The majority of this is _NOT_ my code. I simply ported it from the
// * PERL Spreadsheet::WriteExcel module.
// *
// * The author of the Spreadsheet::WriteExcel module is John McNamara
// * <jmcnamara@cpan.org>
// *
// * I _DO_ maintain this code, and John McNamara has nothing to do with the
// * porting of this code to PHP. Any questions directly related to this
// * class library should be directed to me.
// *
// * License Information:
// *
// * Spreadsheet_Excel_Writer: A library for generating Excel Spreadsheets
// * Copyright (c) 2002-2003 Xavier Noguer xnoguer@rezebra.com
// *
// * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
// */
class BIFFwriter
{
/**
* The byte order of this architecture. 0 => little endian, 1 => big endian.
*
* @var int
*/
private static $byteOrder;
/**
* The string containing the data of the BIFF stream.
*
* @var string
*/
public $_data;
/**
* The size of the data in bytes. Should be the same as strlen($this->_data).
*
* @var int
*/
public $_datasize;
/**
* The maximum length for a BIFF record (excluding record header and length field). See addContinue().
*
* @var int
*
* @see addContinue()
*/
private $limit = 8224;
/**
* Constructor.
*/
public function __construct()
{
$this->_data = '';
$this->_datasize = 0;
}
/**
* Determine the byte order and store it as class data to avoid
* recalculating it for each call to new().
*
* @return int
*/
public static function getByteOrder()
{
if (!isset(self::$byteOrder)) {
// Check if "pack" gives the required IEEE 64bit float
$teststr = pack('d', 1.2345);
$number = pack('C8', 0x8D, 0x97, 0x6E, 0x12, 0x83, 0xC0, 0xF3, 0x3F);
if ($number == $teststr) {
$byte_order = 0; // Little Endian
} elseif ($number == strrev($teststr)) {
$byte_order = 1; // Big Endian
} else {
// Give up. I'll fix this in a later version.
throw new WriterException('Required floating point format not supported on this platform.');
}
self::$byteOrder = $byte_order;
}
return self::$byteOrder;
}
/**
* General storage function.
*
* @param string $data binary data to append
*/
protected function append($data): void
{
if (strlen($data) - 4 > $this->limit) {
$data = $this->addContinue($data);
}
$this->_data .= $data;
$this->_datasize += strlen($data);
}
/**
* General storage function like append, but returns string instead of modifying $this->_data.
*
* @param string $data binary data to write
*
* @return string
*/
public function writeData($data)
{
if (strlen($data) - 4 > $this->limit) {
$data = $this->addContinue($data);
}
$this->_datasize += strlen($data);
return $data;
}
/**
* Writes Excel BOF record to indicate the beginning of a stream or
* sub-stream in the BIFF file.
*
* @param int $type type of BIFF file to write: 0x0005 Workbook,
* 0x0010 Worksheet
*/
protected function storeBof($type): void
{
$record = 0x0809; // Record identifier (BIFF5-BIFF8)
$length = 0x0010;
// by inspection of real files, MS Office Excel 2007 writes the following
$unknown = pack('VV', 0x000100D1, 0x00000406);
$build = 0x0DBB; // Excel 97
$year = 0x07CC; // Excel 97
$version = 0x0600; // BIFF8
$header = pack('vv', $record, $length);
$data = pack('vvvv', $version, $type, $build, $year);
$this->append($header . $data . $unknown);
}
/**
* Writes Excel EOF record to indicate the end of a BIFF stream.
*/
protected function storeEof(): void
{
$record = 0x000A; // Record identifier
$length = 0x0000; // Number of bytes to follow
$header = pack('vv', $record, $length);
$this->append($header);
}
/**
* Writes Excel EOF record to indicate the end of a BIFF stream.
*/
public function writeEof()
{
$record = 0x000A; // Record identifier
$length = 0x0000; // Number of bytes to follow
$header = pack('vv', $record, $length);
return $this->writeData($header);
}
/**
* Excel limits the size of BIFF records. In Excel 5 the limit is 2084 bytes. In
* Excel 97 the limit is 8228 bytes. Records that are longer than these limits
* must be split up into CONTINUE blocks.
*
* This function takes a long BIFF record and inserts CONTINUE records as
* necessary.
*
* @param string $data The original binary data to be written
*
* @return string A very convenient string of continue blocks
*/
private function addContinue($data)
{
$limit = $this->limit;
$record = 0x003C; // Record identifier
// The first 2080/8224 bytes remain intact. However, we have to change
// the length field of the record.
$tmp = substr($data, 0, 2) . pack('v', $limit) . substr($data, 4, $limit);
$header = pack('vv', $record, $limit); // Headers for continue records
// Retrieve chunks of 2080/8224 bytes +4 for the header.
$data_length = strlen($data);
for ($i = $limit + 4; $i < ($data_length - $limit); $i += $limit) {
$tmp .= $header;
$tmp .= substr($data, $i, $limit);
}
// Retrieve the last chunk of data
$header = pack('vv', $record, strlen($data) - $i);
$tmp .= $header;
$tmp .= substr($data, $i);
return $tmp;
}
}
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