Solution to phpExcel memory overflow when exporting files

The content of this article is about the solution to phpExcel memory overflow when exporting files. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

When using PHPExcel to export files, PHP memory overflow errors are often reported because the files are too large. In order to solve this problem, you can use the parameters provided by PHPExcel for optimization. The oversized Excel file mentioned here does not necessarily mean the file size, but more importantly, the data and format stored in the file. If there is a lot of data and the format is relatively rich, it will easily exhaust the memory of PHP.

Information 2 points out that a cell in Excel occupies approximately 1K of memory without caching enabled, and a table with 8,000 rows and 31 columns (248,000 cells) requires 242MB of memory. If caching is enabled, it will drop to 80MB, and the effect is still very obvious.

It should be noted during use that the memory optimization parameters of PHPExcel are not in the PHPExcel object and need to be set before PHPExcel is instantiated.

$cacheMethod = PHPExcel_CachedObjectStorageFactory::cache_to_phpTemp;
$cacheSettings = array( 'memoryCacheSize' => '512MB');
PHPExcel_Settings::setCacheStorageMethod($cacheMethod,$cacheSettings);

$oExcel = new PHPExcel();

Several parameters of PHPExcel_Settings::setCacheStorageMethod()

Serialize the cell data and save it in memory

PHPExcel_CachedObjectStorageFactory::cache_in_memory_serialized;

Serialize the cell and then perform Gzip Compressed and then saved in memory

PHPExcel_CachedObjectStorageFactory::cache_in_memory_gzip;

Cached in a temporary disk file, the speed may be slower

PHPExcel_CachedObjectStorageFactory::cache_to_discISAM;

Saved in php://temp

PHPExcel_CachedObjectStorageFactory::cache_to_phpTemp;

Saved in

$cacheMethod = PHPExcel_CachedObjectStorageFactory::cache_to_memcache;  
$cacheSettings = array( 'memcacheServer'  => 'localhost',  
    'memcachePort'    => 11211,  
    'cacheTime'       => 600  
);  
PHPExcel_Settings::setCacheStorageMethod($cacheMethod, $cacheSettings);

Other ways to reduce memory usage in memcache

If you do not need to read the Excel cell format, you can set it to only read data.

$objReader = PHPExcel_IOFactory::createReader('Excel2007');
$objReader->setReadDataOnly(true);
$objPHPExcel = $objReader->load("test.xlsx”);

If there are multiple Sheets in Excel, but we only need to read a few of them, in order to reduce memory consumption, we can also set it.

$objReader = PHPExcel_IOFactory::createReader('Excel2007');
$objReader->setLoadSheetsOnly( array("Worksheet1", "Worksheet2") );
$objPHPExcel = $objReader->load("test.xlsx”);

If you only need to read a certain area in the Sheet, you can also set a filter.

class MyReadFilter implements PHPExcel_Reader_IReadFilter
{
    public function readCell($column, $row, $worksheetName = '') {
        // Read title row and rows 20 - 30
        if ($row == 1 || ($row >= 20 && $row <= 30)) {
            return true;
        }

        return false;
    }
}

$objReader = PHPExcel_IOFactory::createReader(&#39;Excel2007&#39;);
$objReader->setReadFilter( new MyReadFilter() );
$objPHPExcel = $objReader->load("test.xlsx”);

In the end, I used the following method

// 如果是因为特殊字符引起的，可以在load方法之前加上setReadDataOnly（意思是忽略任何格式的信息）方法，就可以避免 
$objReader->setReadDataOnly(true);//只需要添加这个方法
$objPHPExcel = $objReader->load($uploadFilePath);

Related recommendations:

Solution to the memory overflow error when phpExcel exports a large amount of data

phpexcel Problems related to saving and downloading exported excel files

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