/**
* {@inheritdoc}
*/
public function update(Response $response)
{
// if we have no embedded Response, do nothing
if (0 === $this->embeddedResponses) {
return;
}
// Remove validation related headers in order to avoid browsers using
// their own cache, because some of the response content comes from
// at least one embedded response (which likely has a different caching strategy).
if ($response->isValidateable()) {
$response->setEtag(null);
$response->setLastModified(null);
$this->cacheable = false;
}
if (!$this->cacheable) {
$response->headers->set('Cache-Control', 'no-cache, must-revalidate');
return;
}
$this->ttls[] = $response->getTtl();
$this->maxAges[] = $response->getMaxAge();
if (null !== ($maxAge = min($this->maxAges))) {
$response->setSharedMaxAge($maxAge);
$response->headers->set('Age', $maxAge - min($this->ttls));
}
$response->setMaxAge(0);
}