private function shouldValidate(RequestInterface $request, ResponseInterface $response)
{
if ($request->getMethod() != 'GET' || $request->getConfig()->get('cache.disable')) {
return false;
}
$validate = Utils::getDirective($request, 'Pragma') === 'no-cache' || Utils::getDirective($response, 'Pragma') === 'no-cache' || Utils::getDirective($request, 'must-revalidate') || Utils::getDirective($response, 'must-revalidate') || Utils::getDirective($request, 'no-cache') || Utils::getDirective($response, 'no-cache') || Utils::getDirective($response, 'max-age') === '0' || Utils::getDirective($response, 's-maxage') === '0';
// Use the strong ETag validator if available and the response contains
// no Cache-Control directive
if (!$validate && !$response->hasHeader('Cache-Control') && $response->hasHeader('ETag')) {
$validate = true;
}
return $validate;
}
private function getTtl(ResponseInterface $response)
{
$ttl = 0;
if ($cacheControl = $response->getHeader('Cache-Control')) {
$stale = Utils::getDirective($response, 'stale-if-error');
$ttl += $stale == true ? $ttl : $stale;
$ttl += Utils::getDirective($response, 'max-age');
}
return $ttl ?: $this->defaultTtl;
}
private function validateFailed(RequestInterface $request, ResponseInterface $response)
{
$req = Utils::getDirective($request, 'stale-if-error');
$res = Utils::getDirective($response, 'stale-if-error');
if (!$req && !$res) {
return false;
}
$responseAge = Utils::getResponseAge($response);
$maxAge = Utils::getMaxAge($response);
if ($req && $responseAge - $maxAge > $req || $responseAge - $maxAge > $res) {
return false;
}
return true;
}
/**
* Return the TTL to use when caching a Response (extracted from guzzle/cache-subscriber).
*
* @param ResponseInterface $response Guzzle 4/5 response message.
*
* @link https://github.com/guzzle/cache-subscriber/blob/master/src/CacheStorage.php
*
* @return int
*/
private function getTtl(ResponseInterface $response)
{
$ttl = 0;
if ($response->getHeader('Cache-Control')) {
return $ttl;
}
$maxAge = Utils::getDirective($response, 'max-age');
if (is_numeric($maxAge)) {
$ttl += $maxAge;
}
// According to RFC5861 stale headers are *in addition* to any
// max-age values.
$stale = Utils::getDirective($response, 'stale-if-error');
if (is_numeric($stale)) {
$ttl += $stale;
}
return $ttl;
}
public static function isResponseValid(RequestInterface $request, ResponseInterface $response)
{
$responseAge = Utils::getResponseAge($response);
$maxAge = Utils::getDirective($response, 'max-age');
// Increment the age based on the X-Guzzle-Cache-Date
if ($cacheDate = $response->getHeader('X-Guzzle-Cache-Date')) {
$responseAge += time() - strtotime($cacheDate);
$response->setHeader('Age', $responseAge);
}
// Check the request's max-age header against the age of the response
if ($maxAge !== null && $responseAge > $maxAge) {
return false;
}
// Check the response's max-age header against the freshness level
$freshness = Utils::getFreshness($response);
if ($freshness !== null) {
$maxStale = Utils::getDirective($request, 'max-stale');
if ($maxStale !== null) {
if ($freshness < -1 * $maxStale) {
return false;
}
} elseif ($maxAge !== null && $responseAge > $maxAge) {
return false;
}
}
return true;
}
public static function isResponseValid(RequestInterface $request, ResponseInterface $response)
{
$responseAge = Utils::getResponseAge($response);
$maxAge = Utils::getDirective($response, 'max-age');
// Check the request's max-age header against the age of the response
if ($maxAge !== null && $responseAge > $maxAge) {
return false;
}
// Check the response's max-age header against the freshness level
$freshness = Utils::getFreshness($response);
if ($freshness !== null) {
$maxStale = Utils::getDirective($request, 'max-stale');
if ($maxStale !== null) {
if ($freshness < -1 * $maxStale) {
return false;
}
} elseif ($maxAge !== null && $responseAge > $maxAge) {
return false;
}
}
return true;
}
/**
* Return the TTL to use when caching a Response.
*
* @param ResponseInterface $response The response being cached.
*
* @return int The TTL in seconds.
*/
private function getTtl(ResponseInterface $response)
{
$ttl = 0;
if ($cacheControl = $response->getHeader('Cache-Control')) {
$maxAge = Utils::getDirective($response, 'max-age');
if (is_numeric($maxAge)) {
$ttl += $maxAge;
}
// According to RFC5861 stale headers are *in addition* to any
// max-age values.
$stale = Utils::getDirective($response, 'stale-if-error');
if (is_numeric($stale)) {
$ttl += $stale;
}
} elseif ($expires = $response->getHeader('Expires')) {
$ttl += strtotime($expires) - time();
}
return $ttl ?: $this->defaultTtl;
}
