Skip to content
Preloader helper to create a PHP-ready preload script from Opcache.
Branch: master
Clone or download

 Braden Collum - Unsplash (UL) #9HI8UJMSdZA

Latest Version on Packagist License Coverage Status

Opcache Preloader

Get the best options to keep your application fast as ever, with just one line.

This package generates a PHP 7.4 preloading script from your Opcache statistics automatically. No need to hack your way in.

If you're looking for preloading your Laravel project, check Laraload.

Table of Contents


Require this using Composer into your project

composer require darkghosthunter/preloader

This package doesn't requires ext-opcache to install. Just be sure to have it enabled in your application server.


Anywhere in your application, where Opcache is enabled and running, call Preloader with the path of your Composer Autoloader, and where to output the compiled script:


use DarkGhostHunter\Preloader\Preloader;

Preloader::make()->autoload(__DIR__ . '/vendor/autoloader.php')

This will automatically gather Opcache statistics, and write an optimized preload.php file. In this case, the file will be created in the same directory the Preloader was called.

└── app
    ├── PreloaderCall.php
    └── preload.php

Then, tell PHP to use this file as a preloader at startup in your php.ini.


Restart your PHP process that's using Opcache, and that's all, you're good.

If you use Preloader when Opcache is disabled or without hits, you will get an Exception.

How it works

This package will ask Opcache for statistics about what files are the most requested. You can check this article in Medium about that preload.

Since the best statistics are those you get after your application has been running for a while, you can use your own mechanisms (or the ones provided by the class) to compile the list only after certain conditions are met.

Don't worry, you can configure what and how compile the list.


You can configure the Preloader to run when a condition is met, limit the file list, and where to output the compiled preload list.

when() (optional)

If you don't feel like using Opcache hits, you can just use when(). The Preloader will proceed when the variable being passed evaluates to true, which will be in your hands.

Preloader::make()->when(false); // You will never run, ha ha ha!

You can also use a Closure (Arrow function or any other callable) that returns true.

Preloader::make()->when(fn () => $app->cache()->get('should_run'));

whenHits() (optional)

This is the best way to gather good statistics for a good preloading list if you don't know the real load of your application.

Preloader::make()->whenHits(200000); // After a given number of hits.

The list will be generated when the number of hits set are above the reported by Opcache. This will avoid generating the preload list until the application have done many runs.

Watch out! If you're using overwrite(), the script will be regenerated every time after the number of hits are reached!

whenOneIn() (optional)

The list will be generated one in a given number of chances (the higher is it, the less often will run).

Preloader::make()->whenOneIn(2000); // 1 in 2,000 chances.

This may come in handy using it with overwrite() to constantly recreate the list.


memory() (optional, default)


Set your memory limit in MB. The default of 32MB is enough for most applications. The Preloader will generate a list of files until that memory limit is reached.

This takes into account the memory_consumption key of each script cached in Opcache, not the real file size.

This limit doesn't have any relation with Opcache memory limit.

exclude() (optional)

You can exclude files from the list given by Opcache using exclude(), which accepts a single file or an array of files. These are passed to the glob() method. These file paths must be absolute.


These excluded files will be excluded from the list generation, and won't count for memory limits.

Preloader library files are automatically excluded. You can disable this using includePreloader():


append() (optional)

Of course you can add files using absolute paths manually to the preload script to be generated. Just issue them with append(). These are passed to the glob() method. These file paths must be absolute.


Prepending files will put them after the list generation, so they won't count for the list memory limit.


Any duplicated file appended will be ignored since the list will remove them automatically before compiling the script.

output() (required)

We need to know where to output the script. It's recommended to do it in the same application folder, since most PHP processes will have access to write inside the same directory. If not, you're free to point out where.

Preloader::make()->output(__DIR__ . '/../../my-preloader.php'); 

overwrite() (optional)

Sometimes you may have run your preloader script already. To avoid replacing the list with another one, Preloader by default doesn't do nothing when it detects the script file already exists.

To change this behaviour, you can use the overwrite() method to instruct Preloader to always rewrite the file.


Watch out using this along conditions like whenHits() and when(). If the condition are true, the Preloader will overwrite the preload script... over and over and over again!

shouldCompile()|shouldRequire() (optional)

By default, the Preloader will upload the file to Opcache using require_once. Since this executes the file itself to resolve the links preemptively, some projects may have problems using this.

You can change this using shouldCompile() to use the opcache_compile_file(). This will read the file, but not resolve the links, so the last files on the list may have dangling links (like Traits, Interfaces and other Classes) and some warnings when the file is read by Opcache.


generate() (required)

Once your Preloader configuration is ready, you can generate the list using generate().


This will automatically create a PHP-ready script to preload your application. It will return true on success, and false when the when the conditions are not met or an existing preload file exists that shouldn't be overwritten.

list() (alternative)

Alternatively, you can retrieve the raw list of files as an array using list().


This may become handy if you have your own script, or you just want to tinker around it.

Give me an example

Okay. Let's say we have a framework with 1500 files. We don't know any metrics, so we will blindly push all files that we can inside 256MB of memory after a week has passed after deployment, so it can have enough Opcache statistics.

// index.php

require __DIR__ . '/../vendor/autoload.php';

$app = \Framework\App::make();

$response = $app->run();


// A week after deployment
$weekAfterDeploy = $app->deploymentTimestamp() + (7*24*60*60);

// If a week has passed, and no script was created, do it!
    ->when(time() > $weekAfterDeploy)
    ->autoload(__DIR__ , '/../vendor/autoload.php')
    ->memory(256) // 256MB of memory limit
    ->output(PHP_LOCALSTATEDIR . '/preload.php') // put it in /var.


If you discover any security related issues, please email instead of using the issue tracker.


The MIT License (MIT). Please see License File for more information.

You can’t perform that action at this time.