An implementation of Doctrine/CacheProvider that utilizes a DrupalCacheInterface object for a cache backend.
In a Drupal 7 installation it's recommended that this gets used in conjunction with the composer_manager module for modules using the guzzlehttp/cache-subscriber package.
In practice, using the provider looks something like this in a Drupal 7 installation.
Using the provider would look something like this:
$client = new \GuzzleHttp\Client();
// Get the class used by Drupal for the standard cache.
$cache = variable_get('cache_class_cache', 'DrupalDatabaseCache');
$drupal_cache = new $cache('cache');
// Create a new doctrine cache object, passing in the drupal cache object as a dependency.
$doctrine_cache = new \jlandfried\DrupalCache($drupal_cache);
$storage = array('storage' => new \GuzzleHttp\Subscriber\Cache\CacheStorage($doctrine_cache, null, 3600));
\GuzzleHttp\Subscriber\Cache\CacheSubscriber::attach($client, $storage);
// Do stuff with your guzzle client...I don't claim that this package is complete, bug reports are welcome.