Download from Laravel storage without loading whole file in memory

Question

I am using Laravel Storage and I want to serve users some (larger than memory limit) files. My code was inspired from a post in SO and it goes like this:

$fs = Storage::getDriver(); $stream = $fs->readStream($file->path);  return response()->stream(     function() use($stream) {         fpassthru($stream);     },      200,     [         'Content-Type' => $file->mime,         'Content-disposition' => 'attachment; filename="'.$file->original_name.'"',     ]); 

Unfourtunately, I run into an error for large files:

[2016-04-21 13:37:13] production.ERROR: exception 'Symfony\Component\Debug\Exception\FatalErrorException' with message 'Allowed memory size of 134217728 bytes exhausted (tried to allocate 201740288 bytes)' in /path/app/Http/Controllers/FileController.php:131 Stack trace: #0 /path/vendor/laravel/framework/src/Illuminate/Foundation/Bootstrap/HandleExceptions.php(133): Symfony\Component\Debug\Exception\FatalErrorException->__construct() #1 /path/vendor/laravel/framework/src/Illuminate/Foundation/Bootstrap/HandleExceptions.php(118): Illuminate\Foundation\Bootstrap\HandleExceptions->fatalExceptionFromError() #2 /path/vendor/laravel/framework/src/Illuminate/Foundation/Bootstrap/HandleExceptions.php(0): Illuminate\Foundation\Bootstrap\HandleExceptions->handleShutdown() #3 /path/app/Http/Controllers/FileController.php(131): fpassthru() #4 /path/vendor/symfony/http-foundation/StreamedResponse.php(95): App\Http\Controllers\FileController->App\Http\Controllers\{closure}() #5 /path/vendor/symfony/http-foundation/StreamedResponse.php(95): call_user_func:{/path/vendor/symfony/http-foundation/StreamedResponse.php:95}() #6 /path/vendor/symfony/http-foundation/Response.php(370): Symfony\Component\HttpFoundation\StreamedResponse->sendContent() #7 /path/public/index.php(56): Symfony\Component\HttpFoundation\Response->send() #8 /path/public/index.php(0): {main}() #9 {main}   

It seems that it tries to load all of the file into memory. I was expecting that usage of stream and passthru would not do this... Is there something missing in my code? Do I have to somehow specify chunk size or what?

The versions I am using are Laravel 5.1 and PHP 5.6.

Answer 1

It seems that output buffering is still building up a lot in memory.

Try disabling ob before doing the fpassthru:

function() use($stream) {     while(ob_get_level() > 0) ob_end_flush();     fpassthru($stream); }, 

It could be that there are multiple output buffers active that is why the while is needed.

Answer 2

Instead of loading the whole file into memory at once, try to use fread to read and send it chunk by chunk.

Here is a very good article: http://zinoui.com/blog/download-large-files-with-php

<?php  //disable execution time limit when downloading a big file. set_time_limit(0);  /** @var \League\Flysystem\Filesystem $fs */ $fs = Storage::disk('local')->getDriver();  $fileName = 'bigfile';  $metaData = $fs->getMetadata($fileName); $handle = $fs->readStream($fileName);  header('Pragma: public'); header('Expires: 0'); header('Cache-Control: must-revalidate, post-check=0, pre-check=0'); header('Cache-Control: private', false); header('Content-Transfer-Encoding: binary'); header('Content-Disposition: attachment; filename="' . $metaData['path'] . '";'); header('Content-Type: ' . $metaData['type']);  /*     I've commented the following line out.     Because \League\Flysystem\Filesystem uses int for file size     For file size larger than PHP_INT_MAX (2147483647) bytes     It may return 0, which results in:          Content-Length: 0      and it stops the browser from downloading the file.      Try to figure out a way to get the file size represented by a string.     (e.g. using shell command/3rd party plugin?) */  //header('Content-Length: ' . $metaData['size']);   $chunkSize = 1024 * 1024;  while (!feof($handle)) {     $buffer = fread($handle, $chunkSize);     echo $buffer;     ob_flush();     flush(); }  fclose($handle); exit; ?> 

---

Update

A simpler way to do this: just call

if (ob_get_level()) ob_end_clean(); 

before returning a response.

Credit to @Christiaan

//disable execution time limit when downloading a big file. set_time_limit(0);  /** @var \League\Flysystem\Filesystem $fs */ $fs = Storage::disk('local')->getDriver();  $fileName = 'bigfile';  $metaData = $fs->getMetadata($fileName); $stream = $fs->readStream($fileName);  if (ob_get_level()) ob_end_clean();  return response()->stream(     function () use ($stream) {         fpassthru($stream);     },     200,     [         'Content-Type' => $metaData['type'],         'Content-disposition' => 'attachment; filename="' . $metaData['path'] . '"',     ]);