public function cache(RequestInterface $request, Response $response)
{
$currentTime = time();
$ttl = $request->getParams()->get('cache.override_ttl') ?: $response->getMaxAge() ?: $this->defaultTtl;
if ($cacheControl = $response->getHeader('Cache-Control')) {
$stale = $cacheControl->getDirective('stale-if-error');
$ttl += $stale == true ? $ttl : $stale;
}
// Determine which manifest key should be used
$key = $this->getCacheKey($request);
$persistedRequest = $this->persistHeaders($request);
$entries = array();
if ($manifest = $this->cache->fetch($key)) {
// Determine which cache entries should still be in the cache
$vary = $response->getVary();
foreach (unserialize($manifest) as $entry) {
// Check if the entry is expired
if ($entry[4] < $currentTime) {
continue;
}
$entry[1]['vary'] = isset($entry[1]['vary']) ? $entry[1]['vary'] : '';
if ($vary != $entry[1]['vary'] || !$this->requestsMatch($vary, $entry[0], $persistedRequest)) {
$entries[] = $entry;
}
}
}
// Persist the response body if needed
$bodyDigest = null;
if ($response->getBody() && $response->getBody()->getContentLength() > 0) {
$bodyDigest = $this->getBodyKey($request->getUrl(), $response->getBody());
$this->cache->save($bodyDigest, (string) $response->getBody(), $ttl);
}
array_unshift($entries, array($persistedRequest, $this->persistHeaders($response), $response->getStatusCode(), $bodyDigest, $currentTime + $ttl));
$this->cache->save($key, serialize($entries));
}
/**
* 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;
}
