private function addResponseHeaders(RequestInterface $request, ResponseInterface $response)
{
$params = $request->getConfig();
$lookup = $params['cache_lookup'] . ' from GuzzleCache';
$response->addHeader('X-Cache-Lookup', $lookup);
if ($params['cache_hit'] === true) {
$response->addHeader('X-Cache', 'HIT from GuzzleCache');
} elseif ($params['cache_hit'] == 'error') {
$response->addHeader('X-Cache', 'HIT_ERROR from GuzzleCache');
} else {
$response->addHeader('X-Cache', 'MISS from GuzzleCache');
}
$freshness = Utils::getFreshness($response);
// Only add a Warning header if we are returning a stale response.
if ($params['cache_hit'] && $freshness !== null && $freshness <= 0) {
$response->addHeader('Warning', sprintf('%d GuzzleCache/' . ClientInterface::VERSION . ' "%s"', 110, 'Response is stale'));
}
}
