/** * Check if a cache response satisfies a failed request's caching constraints * * @param RequestInterface $request Request to validate * @param Response $response Response to validate * * @return bool */ public function canResponseSatisfyFailedRequest(RequestInterface $request, Response $response) { $reqc = $request->getHeader('Cache-Control'); $resc = $response->getHeader('Cache-Control'); $requestStaleIfError = $reqc ? $reqc->getDirective('stale-if-error') : null; $responseStaleIfError = $resc ? $resc->getDirective('stale-if-error') : null; if (!$requestStaleIfError && !$responseStaleIfError) { return false; } if (is_numeric($requestStaleIfError) && $response->getAge() - $response->getMaxAge() > $requestStaleIfError) { return false; } if (is_numeric($responseStaleIfError) && $response->getAge() - $response->getMaxAge() > $responseStaleIfError) { return false; } return true; }