/**
* Handle a 304 response and ensure that it is still valid
*
* @param RequestInterface $request Request that was sent
* @param Response $validateResponse Response received
* @param Response $response Original cached response
*
* @return bool Returns true if valid, false if invalid
*/
protected function handle304Response(RequestInterface $request, Response $validateResponse, Response $response)
{
static $replaceHeaders = array('Date', 'Expires', 'Cache-Control', 'ETag', 'Last-Modified');
// Make sure that this response has the same ETag
if ($validateResponse->getEtag() != $response->getEtag()) {
return false;
}
// Replace cached headers with any of these headers from the
// origin server that might be more up to date
$modified = false;
foreach ($replaceHeaders as $name) {
if ($validateResponse->hasHeader($name)) {
$modified = true;
$response->setHeader($name, $validateResponse->getHeader($name));
}
}
// Store the updated response in cache
if ($modified && $this->canCache->canCacheResponse($response)) {
$this->storage->cache($request, $response);
}
return true;
}
