Cannot get cell caching to work in PHPExcel

Question

I've tried every method in the PHPExcel 1.7.8 manual for cell caching, but none work. I still run out of memory every time I try to load an Excel file of about 30 MB.

Here is my code:

    ini_set('memory_limit', '256M'); // Up from default 32MB

    require MODULES_DIR . '/PHPExcel.php';

    $cacheMethod = PHPExcel_CachedObjectStorageFactory::cache_to_discISAM;
    $cacheSettings = array('dir' => '/usr/local/tmp');
    PHPExcel_Settings::setCacheStorageMethod($cacheMethod, $cacheSettings);

    $inputFileType = PHPExcel_IOFactory::identify($dir . $source_file);

    $objReader = PHPExcel_IOFactory::createReader($inputFileType);

    $objReader->setReadDataOnly(true);

    $objPHPExcel = $objReader->load($dir . $source_file);

    $total_sheets = $objPHPExcel->getSheetCount();
    $allSheetName = $objPHPExcel->getSheetNames();

    $objWorksheet = $objPHPExcel->setActiveSheetIndex(0);

    $highestRow = $objWorksheet->getHighestRow();
    $highestColumn = $objWorksheet->getHighestColumn();

    $headingsArray = $objWorksheet->rangeToArray('A1:'.$highestColumn.'1',null, true, true, true);
    $headingsArray = $headingsArray[1];

    $r = -1;
    $namedDataArray = array();

    for ($row = 2; $row <= $highestRow; ++$row) {
        $dataRow = $objWorksheet->rangeToArray('A'.$row.':'.$highestColumn.$row,null, true, true, true);

        if ((isset($dataRow[$row]['A'])) && ($dataRow[$row]['A'] > '')) {
            ++$r;

            foreach($headingsArray as $columnKey => $columnHeading) {
                $namedDataArray[$r][$columnHeading] = $dataRow[$row][$columnKey];
            }
        }
    }

I've tried every one of the cell caching mechanisms all the way down to "cache_to_sqlite3" but none of them work.

Can someone tell me what I am doing wrong here?

EDIT: Apparently I skipped over the "cache_to_sqlite" option. I tried that and it started caching. However, it still runs out of memory during the caching process on a 30 MB file with 256MB of memory available. Here is the error:

 Fatal error: Uncaught exception 'Exception' with message 'out of memory' in modules/PHPExcel/CachedObjectStorage/SQLite.php:64 Stack trace: #0 modules/PHPExcel/CachedObjectStorage/SQLite.php(81): PHPExcel_CachedObjectStorage_SQLite->_storeData() #1 modules/PHPExcel/Worksheet.php(1123): PHPExcel_CachedObjectStorage_SQLite->addCacheData('X2498702', Object(PHPExcel_Cell)) #2 modules/PHPExcel/Reader/Excel5.php(3549): PHPExcel_Worksheet->getCell('X2498702') #3 modules/PHPExcel/Reader/Excel5.php(894): PHPExcel_Reader_Excel5->_readLabelSst() #4 modules/updater.inc.php(1478): PHPExcel_Reader_Excel5->load('modules/p...') #5 modules/updater.php(204): Updater->process_xls('prods.xls') #6 {main} thrown in modules/PHPExcel/CachedObjectStorage/SQLite.php on line 64

Answer 1

Cell caching doesn't eliminate memory usage: it reduces it. Clearly you still don't have enough PHP memory to handle a workbook this large.

One possible issue is the reference to cell 'X2498702'... Excel BIFF files (of the type loaded by the Excel5 Reader) have an upper limit of 65536 rows, so something has clearly gone very wrong here if the reader is trying to load a cell in row 2498702. The problem isn't cell caching, it's the Excel5 Reader finding data that either it's misinterpreting, or that shouldn't exist in this Excel file.

Can you please upload a copy of this particular file (if confidentiality permist) to the PHPExcel website so we can take a look and try to ascertain exactly what is going wrong.