PHPExcel write xlsx file, allowed memory size

Question

When I try to generate big file with PHPExcel I get this error:

Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 67 bytes)

here's example code which causes this:

$CI = & get_instance ();
        $CI->load->library ( 'export/PHPExcel' );

        $objPHPExcel = new PHPExcel ();
        $objPHPExcel->setActiveSheetIndex ( 0 );

        $rowCount = 1; 
        $objPHPExcel->getProperties()->setCreator("Maarten Balliauw");
        $objPHPExcel->getProperties()->setLastModifiedBy("Maarten Balliauw");
        $objPHPExcel->getProperties()->setTitle("Office 2007 XLSX Test Document");
    $objPHPExcel->getProperties()->setSubject("Office 2007 XLSX Test Document");
    $objPHPExcel->getProperties()->setDescription("Test document for Office 2007 XLSX, generated using PHP classes.");
    $objPHPExcel->getActiveSheet()->SetCellValue('A'.$rowCount,'title'.$rowCount);
    $objPHPExcel->getActiveSheet()->SetCellValue('B'.$rowCount,'title'.$rowCount);
    $objPHPExcel->getActiveSheet()->SetCellValue('C'.$rowCount,'title'.$rowCount);
    $objPHPExcel->getActiveSheet()->SetCellValue('D'.$rowCount,'title'.$rowCount);
    $objPHPExcel->getActiveSheet()->SetCellValue('E'.$rowCount,'title'.$rowCount);
    $objPHPExcel->getActiveSheet()->SetCellValue('F'.$rowCount,'title'.$rowCount);

    for($i=0; $i<1000000; $i++){ 
        $rowCount++;
        $objPHPExcel->getActiveSheet()->SetCellValue('A'.$rowCount, "xyz".$rowCount);
        $objPHPExcel->getActiveSheet()->SetCellValue('B'.$rowCount, "xyz".$rowCount);
        $objPHPExcel->getActiveSheet()->SetCellValue('C'.$rowCount, "xyz".$rowCount);
        $objPHPExcel->getActiveSheet()->SetCellValue('D'.$rowCount, "xyz".$rowCount);
        $objPHPExcel->getActiveSheet()->SetCellValue('E'.$rowCount, "xyz".$rowCount);
        $objPHPExcel->getActiveSheet()->SetCellValue('F'.$rowCount, "xyz".$rowCount);
    } 


    header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
    header('Content-Disposition: attachment;filename="your_name.xls"');
    header('Cache-Control: max-age=0');  
    $objWriter = new PHPExcel_Writer_Excel2007 ( $objPHPExcel );
    $objWriter->save ( 'php://output' );

Now my question is how to avoid this issue, when I want to generate big xlsx files with PHPExcel? Or maybe you know better lirary for that? I can't change apache/php config to have more memory avaliable. Solution shouldn't depend on memory.

Answer 1

By default PHPExcel uses memory for cacheing before you save the result to file or php://output. You can switch to using php_temp, which is slower, but cheaper in terms of RAM.

Make sure to set settings before creating an instance of PHPExcel:

    $cacheMethod = \PHPExcel_CachedObjectStorageFactory::cache_to_phpTemp;
    $cacheSettings = ['memoryCacheSize' => '128MB'];
    \PHPExcel_Settings::setCacheStorageMethod($cacheMethod, $cacheSettings);

    $excelObject = new \PHPExcel();

Threre are also other values available for cacheMethod, such as MemCache, APC, ISAM, though I haven't tried them. You can see them in the docs of \\PHPExcel_CachedObjectStorageFactory.

Hope it helps. Good luck!