/**
* @param RequestInterface $request
* @param ResponseInterface $response
* @return CacheEntry|null entry to save, null if can't cache it
*/
protected function getCacheObject(RequestInterface $request, ResponseInterface $response)
{
if (!isset($this->statusAccepted[$response->getStatusCode()])) {
// Don't cache it
return;
}
$cacheControl = new KeyValueHttpHeader($response->getHeader('Cache-Control'));
$varyHeader = new KeyValueHttpHeader($response->getHeader('Vary'));
if ($varyHeader->has('*')) {
// This will never match with a request
return;
}
if ($cacheControl->has('no-store')) {
// No store allowed (maybe some sensitives data...)
return;
}
if ($cacheControl->has('no-cache')) {
// Stale response see RFC7234 section 5.2.1.4
$entry = new CacheEntry($request, $response, new \DateTime('-1 seconds'));
return $entry->hasValidationInformation() ? $entry : null;
}
foreach ($this->ageKey as $key) {
if ($cacheControl->has($key)) {
return new CacheEntry($request, $response, new \DateTime('+' . (int) $cacheControl->get($key) . 'seconds'));
}
}
if ($response->hasHeader('Expires')) {
$expireAt = \DateTime::createFromFormat(\DateTime::RFC1123, $response->getHeaderLine('Expires'));
if ($expireAt !== false) {
return new CacheEntry($request, $response, $expireAt);
}
}
return new CacheEntry($request, $response, new \DateTime('-1 seconds'));
}
