dnomyar/php-rate-limiter

Simple rate limiter

1.0.2 2022-09-01 17:03 UTC

Requires

• php: >=7.2
• phpoption/phpoption: ^1.9

Requires (Dev)

• phpunit/phpunit: ^8
• vimeo/psalm: ^4.26

MIT

• Damien R

README

This is a low budget rate limiter. Low budget because it does not require any additional tool to work. It uses the file system as a repository. It can be used to protect a public form from bots or limit by user.

The current implementation allows to atomically update the bucket. If another request is trying to update the save bucket at the same it will throw an Exception.

Usage

This library provides a RateLimiter class that need to be initialized with a identificator corresponding to the resources that need to be limited. For instance:

• limit the number of submitions to a public page. In that case, the id could be business-description
• limit the number of call per user. In that case, the id could be business-description-<user-id>

use Dnomyar\PhpFileSystemRateLimiter\Domain\RateLimiter;
use Dnomyar\PhpFileSystemRateLimiter\Domain\Model\Configuration\BucketSize;
use Dnomyar\PhpFileSystemRateLimiter\Domain\Model\Configuration\BucketTime;
use Dnomyar\PhpFileSystemRateLimiter\Domain\Model\Configuration\Duration;
use Dnomyar\PhpFileSystemRateLimiter\Infrastructure\Repository\LockFileImplementation;
use Dnomyar\PhpFileSystemRateLimiter\Infrastructure\Repository\BucketSerializerImplementation;
use Dnomyar\PhpFileSystemRateLimiter\Infrastructure\Repository\FileSystemFileAdapterImplementation;
use Dnomyar\PhpFileSystemRateLimiter\Infrastructure\Repository\FileSystemBucketRepository;

$rateLimiter = new RateLimiter(
     new BucketTime(Duration::seconds(10)),
     BucketSize::createBucketSize(6),
     new FileSystemBucketRepository(
        new FileSystemFileAdapterImplementation(),
        new BucketSerializerImplementation(),
        new LockFileImplementation()
     )
);

/*
 * return true of false if the call is allowed
 * thows a BucketRepositoryException if another request is trying to use the feature at the same time.
 */
$rateLimiter->allowCall('id-to-change');

Limitation

If you are looking to use that for your project, use caution. This library was built to respect two important constraints: not using additionnal tool and a low level of parallel request for the same identificator.

Also, it would cause problems in case of a pick of load. It is advise to run load testing before using this library.