Stiphle

Install via Composer

composer require davedevelopment/stiphle

What is it?

Stiphle is a little library to try and provide an easy way of throttling/rate limit requests, for those without fancy hardware etc.

How does it work?

You create a throttle, and ask it how long you should wait. For example, given that $identifier is some means of identifying whatever it is you're throttling, and you want to throttle it to 5 requests per second:

<?php

$throttle = new Stiphle\Throttle\LeakyBucket;
$identifier = 'dave';
while(true) {
    // the throttle method returns the amount of milliseconds it slept for
    echo $throttle->throttle($identifier, 5, 1000);
}
# 0 0 0 0 0 200 200....

Use combinations of values to provide bursting etc, though use carefully as it screws with your mind

<?php

$throttle = new Stiphle\Throttle\LeakyBucket;
$identifier = 'dave';
for(;;) {
    /**
     * Allow upto 5 per second, but limit to 20 a minute - I think
     **/
    echo "a:" . $throttle->throttle($identifier, 5, 1000);
    echo " b:" . $throttle->throttle($identifier, 20, 60000);
    echo "\n";
}
#a:0 b:0
#a:0 b:0
#a:0 b:0
#a:0 b:0
#a:0 b:0
#a:199 b:0
#a:200 b:0
#a:199 b:0
#a:200 b:0
#a:200 b:0
#a:199 b:0
#a:200 b:0
#a:199 b:0
#a:200 b:0
#a:200 b:0
#a:199 b:0
#a:200 b:0
#a:200 b:0
#a:199 b:0
#a:200 b:0
#a:199 b:0
#a:200 b:2600
#a:0 b:3000
#a:0 b:2999

Throttle Strategies

There are currently two types of throttles, Leaky Bucket and a simple fixed time window.

/**
 * Throttle to 1000 per *rolling* 24 hours, e.g. the counter will not reset at
 * midnight
 */
$throttle = new Stiphle\Throttle\LeakyBucket;
$throttle->throttle('api.request', 1000, 86400000);

/**
 * Throttle to 1000 per calendar day, counter will reset at midnight
 */
$throttle = new Stiphle\Throttle\TimeWindow;
$throttle->throttle('api.request', 1000, 86400000);

NB: The current implementation of the TimeWindow throttle will only work on 64-bit architectures!

Storage

Stiphle currently ships with 5 storage engines

• In process
• APC
• Memcached
• Doctrine Cache
• Redis

Stiphle uses the in process storage by default. A different storage engine can be injected after object creation.

$throttle = new Stiphle\Throttle\LeakyBucket();
$storage = new \Stiphle\Storage\Memcached(new \Memcached());
$throttle->setStorage($storage);

Todo

• More Tests!
• Decent Unit tests
• More throttling methods
• More storage adapters, the current ones are a little volatile, Mongo, Cassandra, MemcacheDB etc

Copyright

Copyright (c) 2011 Dave Marshall. See LICENCE for further details