CacheDriver.php

<?php

// Imagine we're in class `CacheDriver`
// ...

public function save($key, Closure $callback, $ttl = 0, $stampedeTtl = null)
{
    $data = $this->cache->fetch($key);

    if (false !== $data) {
        return $data;
    }

    if (null !== $stampede) {
        $stampede = max((double) $stampede, 0.001); // Prevent infinite TTL
        // Data is being resolved already, wait for previus request
        while ('__STAMPEDE__' === $data) {
            // Wait 1/20th of the stampede TTL, to give the CPU a chance
            sleep($stampede / 20);
            $data = $this->cache->fetch($key);
        }
    }

    if ($data === false) {
        if (null !== $stampedeTtl) {
            // Acquire lock
            $this->cache->save($key, '__STAMPEDE__', $stampedeTtl);
        }
        // Resolve the actual data from the callback
        $data = $callback();
    }

    $this->cache->save($key, $data, $ttl);

    return $data;
}

CacheDriverImplementation.php

<?php

$cache = new MyChoiceOfCache();

$cacheTtl = 3600;
$stampedeTtl = 5;

$cacheDriver = new CacheDriver($cache);
$cacheDriver->save("recent_tweets", function() {
    return file_get_contents("https://api.twitter.com/1.1/search/tweets.json?q=@lavoiesl");
}, 5000, 5);