https://github.com/xp-forge/ratelimit

Rate limiting
https://github.com/xp-forge/ratelimit

ratelimiter xp-framework

Last synced: about 2 months ago
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Rate limiting

• Host: GitHub
• URL: https://github.com/xp-forge/ratelimit
• Owner: xp-forge
• Created: 2015-01-02T21:53:14.000Z (almost 10 years ago)
• Default Branch: master
• Last Pushed: 2024-03-24T13:13:40.000Z (9 months ago)
• Last Synced: 2024-11-06T21:04:06.910Z (about 2 months ago)
• Topics: ratelimiter, xp-framework
• Language: PHP
• Size: 54.7 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: ChangeLog.md

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README

        
Rate limiting

=============

[![Build status on GitHub](https://github.com/xp-forge/ratelimit/workflows/Tests/badge.svg)](https://github.com/xp-forge/ratelimit/actions)

[![XP Framework Module](https://raw.githubusercontent.com/xp-framework/web/master/static/xp-framework-badge.png)](https://github.com/xp-framework/core)

[![BSD Licence](https://raw.githubusercontent.com/xp-framework/web/master/static/licence-bsd.png)](https://github.com/xp-framework/core/blob/master/LICENCE.md)

[![Requires PHP 7.0+](https://raw.githubusercontent.com/xp-framework/web/master/static/php-7_0plus.svg)](http://php.net/)

[![Supports PHP 8.0+](https://raw.githubusercontent.com/xp-framework/web/master/static/php-8_0plus.svg)](http://php.net/)

[![Latest Stable Version](https://poser.pugx.org/xp-forge/ratelimit/version.png)](https://packagist.org/packages/xp-forge/ratelimit)

A rate limiting can be used to limit the rate at which physical or logical resources are accessed, e.g. to protect them from intentional or unintentional overuse.

Restricting usage

-----------------

Imagine you don't want to run more than two tasks per second:

```php

use util\invoke\RateLimiting;

$rateLimiter= new RateLimiting(2);

foreach ($tasks as $task) {

  $rateLimiter->acquire();    // will wait if necessary

  $task->run();

}

```

Restricting bandwidth

---------------------

You can implement bandwidth throttling by acquiring a permit for each byte:

```php

use util\invoke\{RateLimiting, Rate, Per};

$rateLimiter= new RateLimiting(new Rate(1000000, Per::$MINUTE));

while ($bytes= $source->read()) {

  $rateLimiter->acquire(strlen($bytes));

  $target->write($bytes);

}

```

Rate-limiting users

-------------------

Implement a filter like the following:

```php

use web\{Filter, Error};

use util\invoke\{RateLimiting, Rate, Per};

class RateLimitingFilter implements Filter {

  private $rates, $rate, $timeout;

  public function __construct(KeyValueStorage $rates) {

    $this->rates= $rates;

    $this->rate= new Rate(5000, Per::$HOUR);

    $this->timeout= 0.2;

  }

  public function filter($request, $response, $invocation) {

    $remote= $request->header('Remote-Addr');

    $limits= $this->rates->get($remote) ?: new RateLimiting($this->rate);

    $permitted= $limits->tryAcquiring(1, $this->timeout);

    $this->rates->put($remote, $limits);

    $response->header('X-RateLimit-Limit', $limits->rate()->value());

    $response->header('X-RateLimit-Remaining', $limits->remaining());

    $response->header('X-RateLimit-Reset', $limits->resetTime());

    if (!$permitted) {

      throw new Error(429, 'Rate limit exceeded');

    }

    return $invocation->proceed($request, $response);

  }

}

```

Further reading

---------------

* [RateLimiter - discovering Google Guava](http://www.nurkiewicz.com/2012/09/ratelimiter-discovering-google-guava.html) by Tomasz Nurkiewicz

* [Guava's RateLimiter class](http://docs.guava-libraries.googlecode.com/git/javadoc/com/google/common/util/concurrent/RateLimiter.html) - which is what this project was inspired from.