806 lines
25 KiB
PHP
806 lines
25 KiB
PHP
<?php
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namespace SilverStripe\Control\Middleware;
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use InvalidArgumentException;
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use SilverStripe\Control\HTTP;
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use SilverStripe\Control\HTTPRequest;
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use SilverStripe\Control\HTTPResponse;
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use SilverStripe\Control\HTTPResponse_Exception;
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use SilverStripe\Core\Config\Configurable;
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use SilverStripe\Core\Injector\Injectable;
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use SilverStripe\Core\Injector\Injector;
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use SilverStripe\Core\Resettable;
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use SilverStripe\ORM\FieldType\DBDatetime;
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use SilverStripe\Dev\Deprecation;
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class HTTPCacheControlMiddleware implements HTTPMiddleware, Resettable
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{
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use Configurable;
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use Injectable;
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const STATE_ENABLED = 'enabled';
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const STATE_PUBLIC = 'public';
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const STATE_PRIVATE = 'private';
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const STATE_DISABLED = 'disabled';
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/**
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* Generate response for the given request
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*
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* @todo Refactor HTTP::add_cache_headers() (e.g. etag handling) into this middleware
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*
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* @param HTTPRequest $request
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* @param callable $delegate
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* @return HTTPResponse
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* @throws HTTPResponse_Exception
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*/
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public function process(HTTPRequest $request, callable $delegate)
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{
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try {
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$response = $delegate($request);
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} catch (HTTPResponse_Exception $ex) {
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$response = $ex->getResponse();
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}
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if (!$response) {
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return null;
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}
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// Update state based on current request and response objects
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$this->augmentState($request, $response);
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// Update state based on deprecated HTTP settings
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Deprecation::withNoReplacement(function () use ($request, $response) {
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HTTP::augmentState($request, $response);
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});
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// Add all headers to this response object
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$this->applyToResponse($response);
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if (isset($ex)) {
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throw $ex;
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}
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return $response;
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}
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/**
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* List of states, each of which contains a key of standard directives.
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* Each directive should either be a numeric value, true to enable,
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* or (bool)false or null to disable.
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* Top level key states include `disabled`, `private`, `public`, `enabled`
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* in descending order of precedence.
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*
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* This allows directives to be set independently for individual states.
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*
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* @var array
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*/
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protected $stateDirectives = [
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self::STATE_DISABLED => [
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'no-cache' => true,
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'no-store' => true,
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'must-revalidate' => true,
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],
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self::STATE_PRIVATE => [
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'private' => true,
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'must-revalidate' => true,
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],
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self::STATE_PUBLIC => [
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'public' => true,
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'must-revalidate' => true,
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],
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self::STATE_ENABLED => [
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'no-cache' => true,
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'must-revalidate' => true,
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]
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];
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/**
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* Set default state
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*
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* @config
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* @var string
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*/
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private static $defaultState = self::STATE_ENABLED;
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/**
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* Current state
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*
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* @var string
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*/
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protected $state = null;
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/**
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* Forcing level of previous setting; higher number wins
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* Combination of consts below
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*
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* @var int
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*/
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protected $forcingLevel = null;
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/**
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* List of vary keys
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*
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* @var array|null
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*/
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protected $vary = null;
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/**
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* Latest modification date for this response
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*
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* @var int
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*/
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protected $modificationDate;
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/**
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* Default vary
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*
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* @var array
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*/
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private static $defaultVary = [
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"X-Forwarded-Protocol" => true,
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];
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/**
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* Default forcing level
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*
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* @config
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* @var int
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*/
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private static $defaultForcingLevel = 0;
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/**
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* Forcing level forced, optionally combined with one of the below.
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*/
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const LEVEL_FORCED = 10;
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/**
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* Forcing level caching disabled. Overrides public/private.
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*/
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const LEVEL_DISABLED = 3;
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/**
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* Forcing level private-cached. Overrides public.
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*/
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const LEVEL_PRIVATE = 2;
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/**
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* Forcing level public cached. Lowest priority.
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*/
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const LEVEL_PUBLIC = 1;
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/**
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* Forcing level caching enabled.
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*/
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const LEVEL_ENABLED = 0;
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/**
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* A list of allowed cache directives for HTTPResponses
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*
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* This doesn't include any experimental directives,
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* use the config system to add to these if you want to enable them
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*
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* @config
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* @var array
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*/
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private static $allowed_directives = [
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'public',
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'private',
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'no-cache',
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'max-age',
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's-maxage',
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'must-revalidate',
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'proxy-revalidate',
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'no-store',
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'no-transform',
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];
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/**
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* Get current vary keys
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*
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* @return array
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*/
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public function getVary()
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{
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// Explicitly set vary
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if (isset($this->vary)) {
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return $this->vary;
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}
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// Load default from config
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$defaultVary = $this->config()->get('defaultVary');
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return array_keys(array_filter($defaultVary ?? []));
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}
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/**
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* Add a vary
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*
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* @param string|array $vary
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* @return $this
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*/
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public function addVary($vary)
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{
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$combied = $this->combineVary($this->getVary(), $vary);
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$this->setVary($combied);
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return $this;
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}
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/**
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* Set vary
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*
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* @param array|string $vary
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* @return $this
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*/
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public function setVary($vary)
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{
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$this->vary = $this->combineVary($vary);
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return $this;
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}
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/**
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* Combine vary strings/arrays into a single array, or normalise a single vary
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*
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* @param string|array[] $varies Each vary as a separate arg
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* @return array
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*/
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protected function combineVary(...$varies)
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{
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$merged = [];
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foreach ($varies as $vary) {
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if ($vary && is_string($vary)) {
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$vary = array_filter(preg_split("/\s*,\s*/", trim($vary ?? '')) ?? []);
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}
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if ($vary && is_array($vary)) {
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$merged = array_merge($merged, $vary);
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}
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}
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return array_unique($merged ?? []);
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}
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/**
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* Register a modification date. Used to calculate the "Last-Modified" HTTP header.
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* Can be called multiple times, and will automatically retain the most recent date.
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*
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* @param string|int $date Date string or timestamp
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* @return HTTPCacheControlMiddleware
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*/
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public function registerModificationDate($date)
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{
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$timestamp = is_numeric($date) ? $date : strtotime($date ?? '');
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if ($timestamp > $this->modificationDate) {
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$this->modificationDate = $timestamp;
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}
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return $this;
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}
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/**
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* Set current state. Should only be invoked internally after processing precedence rules.
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*
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* @param string $state
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* @return $this
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*/
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protected function setState($state)
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{
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if (!array_key_exists($state, $this->stateDirectives ?? [])) {
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throw new InvalidArgumentException("Invalid state {$state}");
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}
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$this->state = $state;
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return $this;
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}
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/**
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* Get current state
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*
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* @return string
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*/
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public function getState()
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{
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return $this->state ?: $this->config()->get('defaultState');
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}
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/**
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* Instruct the cache to apply a change with a given level, optionally
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* modifying it with a force flag to increase priority of this action.
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*
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* If the apply level was successful, the change is made and the internal level
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* threshold is incremented.
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*
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* @param int $level Priority of the given change
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* @param bool $force If usercode has requested this action is forced to a higher priority.
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* Note: Even if $force is set to true, other higher-priority forced changes can still
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* cause a change to be rejected if it is below the required threshold.
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* @return bool True if the given change is accepted, and that the internal
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* level threshold is updated (if necessary) to the new minimum level.
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*/
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protected function applyChangeLevel($level, $force)
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{
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$forcingLevel = $level + ($force ? self::LEVEL_FORCED : 0);
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if ($forcingLevel < $this->getForcingLevel()) {
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return false;
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}
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$this->forcingLevel = $forcingLevel;
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return true;
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}
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/**
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* Low level method for setting directives include any experimental or custom ones added via config.
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* You need to specify the state (or states) to apply this directive to.
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* Can also remove directives with false
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*
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* @param array|string $states State(s) to apply this directive to
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* @param string $directive
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* @param int|string|bool $value Flag to set for this value. Set to false to remove, or true to set.
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* String or int value assign a specific value.
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* @return $this
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*/
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public function setStateDirective($states, $directive, $value = true)
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{
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if ($value === null) {
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throw new InvalidArgumentException("Invalid directive value");
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}
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// make sure the directive is in the list of allowed directives
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$allowedDirectives = $this->config()->get('allowed_directives');
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$directive = strtolower($directive ?? '');
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if (!in_array($directive, $allowedDirectives ?? [])) {
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throw new InvalidArgumentException('Directive ' . $directive . ' is not allowed');
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}
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foreach ((array)$states as $state) {
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if (!array_key_exists($state, $this->stateDirectives ?? [])) {
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throw new InvalidArgumentException("Invalid state {$state}");
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}
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// Set or unset directive
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if ($value === false) {
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unset($this->stateDirectives[$state][$directive]);
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} else {
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$this->stateDirectives[$state][$directive] = $value;
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}
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}
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return $this;
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}
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/**
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* Low level method to set directives from an associative array
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*
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* @param array|string $states State(s) to apply this directive to
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* @param array $directives
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* @return $this
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*/
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public function setStateDirectivesFromArray($states, $directives)
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{
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foreach ($directives as $directive => $value) {
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$this->setStateDirective($states, $directive, $value);
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}
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return $this;
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}
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/**
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* Low level method for removing directives
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*
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* @param array|string $states State(s) to remove this directive from
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* @param string $directive
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* @return $this
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*/
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public function removeStateDirective($states, $directive)
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{
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$this->setStateDirective($states, $directive, false);
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return $this;
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}
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/**
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* Low level method to check if a directive is currently set
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*
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* @param string $state State(s) to apply this directive to
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* @param string $directive
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* @return bool
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*/
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public function hasStateDirective($state, $directive)
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{
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$directive = strtolower($directive ?? '');
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return isset($this->stateDirectives[$state][$directive]);
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}
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/**
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* Check if the current state has the given directive.
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*
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* @param string $directive
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* @return bool
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*/
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public function hasDirective($directive)
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{
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return $this->hasStateDirective($this->getState(), $directive);
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}
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/**
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* Low level method to get the value of a directive for a state.
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* Returns false if there is no directive.
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* True means the flag is set, otherwise the value of the directive.
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*
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* @param string $state
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* @param string $directive
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* @return int|string|bool
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*/
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public function getStateDirective($state, $directive)
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{
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$directive = strtolower($directive ?? '');
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if (isset($this->stateDirectives[$state][$directive])) {
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return $this->stateDirectives[$state][$directive];
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}
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return false;
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}
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/**
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* Get the value of the given directive for the current state
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*
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* @param string $directive
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* @return bool|int|string
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*/
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public function getDirective($directive)
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{
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return $this->getStateDirective($this->getState(), $directive);
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}
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/**
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* Get directives for the given state
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*
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* @param string $state
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* @return array
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*/
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public function getStateDirectives($state)
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{
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return $this->stateDirectives[$state];
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}
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/**
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* Get all directives for the currently active state
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*
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* @return array
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*/
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public function getDirectives()
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{
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return $this->getStateDirectives($this->getState());
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}
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/**
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* The cache should not store anything about the client request or server response.
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* Affects all non-disabled states. Use setStateDirective() instead to set for a single state.
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* Set the no-store directive (also removes max-age and s-maxage for consistency purposes)
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*
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* @param bool $noStore
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*
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* @return $this
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*/
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public function setNoStore($noStore = true)
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{
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// Affect all non-disabled states
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$applyTo = [self::STATE_ENABLED, self::STATE_PRIVATE, self::STATE_PUBLIC];
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if ($noStore) {
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$this->setStateDirective($applyTo, 'no-store');
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$this->removeStateDirective($applyTo, 'max-age');
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$this->removeStateDirective($applyTo, 's-maxage');
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} else {
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$this->removeStateDirective($applyTo, 'no-store');
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}
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return $this;
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}
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/**
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* Forces caches to submit the request to the origin server for validation before releasing a cached copy.
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* Affects all non-disabled states. Use setStateDirective() instead to set for a single state.
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*
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* @param bool $noCache
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* @return $this
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*/
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public function setNoCache($noCache = true)
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{
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// Affect all non-disabled states
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$applyTo = [self::STATE_ENABLED, self::STATE_PRIVATE, self::STATE_PUBLIC];
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if ($noCache) {
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$this->setStateDirective($applyTo, 'no-cache');
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$this->removeStateDirective($applyTo, 'max-age');
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$this->removeStateDirective($applyTo, 's-maxage');
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} else {
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$this->removeStateDirective($applyTo, 'no-cache');
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}
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return $this;
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}
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/**
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* Specifies the maximum amount of time (seconds) a resource will be considered fresh.
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* This directive is relative to the time of the request.
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* Affects all non-disabled states. Use enableCache(), publicCache() or
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* setStateDirective() instead to set the max age for a single state.
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*
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* @param int $age
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* @return $this
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*/
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public function setMaxAge($age)
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{
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// Affect all non-disabled states
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$applyTo = [self::STATE_ENABLED, self::STATE_PRIVATE, self::STATE_PUBLIC];
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$this->setStateDirective($applyTo, 'max-age', $age);
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if ($age) {
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$this->removeStateDirective($applyTo, 'no-cache');
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$this->removeStateDirective($applyTo, 'no-store');
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}
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return $this;
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}
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/**
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* Overrides max-age or the Expires header, but it only applies to shared caches (e.g., proxies)
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* and is ignored by a private cache.
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* Affects all non-disabled states. Use setStateDirective() instead to set for a single state.
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*
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* @param int $age
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* @return $this
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*/
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public function setSharedMaxAge($age)
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{
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// Affect all non-disabled states
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$applyTo = [self::STATE_ENABLED, self::STATE_PRIVATE, self::STATE_PUBLIC];
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$this->setStateDirective($applyTo, 's-maxage', $age);
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if ($age) {
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$this->removeStateDirective($applyTo, 'no-cache');
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$this->removeStateDirective($applyTo, 'no-store');
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}
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return $this;
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}
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/**
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* The cache must verify the status of the stale resources before using it and expired ones should not be used.
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* Affects all non-disabled states. Use setStateDirective() instead to set for a single state.
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*
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* @param bool $mustRevalidate
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* @return $this
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*/
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public function setMustRevalidate($mustRevalidate = true)
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{
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$applyTo = [self::STATE_ENABLED, self::STATE_PRIVATE, self::STATE_PUBLIC];
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$this->setStateDirective($applyTo, 'must-revalidate', $mustRevalidate);
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return $this;
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}
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/**
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* Simple way to set cache control header to a cacheable state.
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* Needs either `setMaxAge()` or the `$maxAge` method argument in order to activate caching.
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*
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* The resulting cache-control headers will be chosen from the 'enabled' set of directives.
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*
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* Does not set `public` directive. Usually, `setMaxAge()` is sufficient. Use `publicCache()` if this is explicitly required.
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* See https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching#public_vs_private
|
|
*
|
|
* @see https://docs.silverstripe.org/en/developer_guides/performance/http_cache_headers/
|
|
* @param bool $force Force the cache to public even if its unforced private or public
|
|
* @param int $maxAge Shortcut for `setMaxAge()`, which is required to actually enable the cache.
|
|
* @return $this
|
|
*/
|
|
public function enableCache($force = false, $maxAge = null)
|
|
{
|
|
// Only execute this if its forcing level is high enough
|
|
if ($this->applyChangeLevel(self::LEVEL_ENABLED, $force)) {
|
|
$this->setState(self::STATE_ENABLED);
|
|
}
|
|
|
|
if (!is_null($maxAge)) {
|
|
$this->setMaxAge($maxAge);
|
|
}
|
|
|
|
return $this;
|
|
}
|
|
|
|
/**
|
|
* Simple way to set cache control header to a non-cacheable state.
|
|
* Use this method over `privateCache()` if you are unsure about caching details.
|
|
* Takes precedence over unforced `enableCache()`, `privateCache()` or `publicCache()` calls.
|
|
*
|
|
* The resulting cache-control headers will be chosen from the 'disabled' set of directives.
|
|
*
|
|
* Removes all state and replaces it with `no-cache, no-store, must-revalidate`. Although `no-store` is sufficient
|
|
* the others are added under recommendation from Mozilla (https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control#Examples)
|
|
*
|
|
* Does not set `private` directive, use `privateCache()` if this is explicitly required.
|
|
* See https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching#public_vs_private
|
|
*
|
|
* @see https://docs.silverstripe.org/en/developer_guides/performance/http_cache_headers/
|
|
* @param bool $force Force the cache to disabled even if it's forced private or public
|
|
* @return $this
|
|
*/
|
|
public function disableCache($force = false)
|
|
{
|
|
// Only execute this if its forcing level is high enough
|
|
if ($this->applyChangeLevel(self::LEVEL_DISABLED, $force)) {
|
|
$this->setState(self::STATE_DISABLED);
|
|
}
|
|
return $this;
|
|
}
|
|
|
|
/**
|
|
* Advanced way to set cache control header to a non-cacheable state.
|
|
* Indicates that the response is intended for a single user and must not be stored by a shared cache.
|
|
* A private cache (e.g. Web Browser) may store the response.
|
|
*
|
|
* The resulting cache-control headers will be chosen from the 'private' set of directives.
|
|
*
|
|
* @see https://docs.silverstripe.org/en/developer_guides/performance/http_cache_headers/
|
|
* @param bool $force Force the cache to private even if it's forced public
|
|
* @return $this
|
|
*/
|
|
public function privateCache($force = false)
|
|
{
|
|
// Only execute this if its forcing level is high enough
|
|
if ($this->applyChangeLevel(self::LEVEL_PRIVATE, $force)) {
|
|
$this->setState(self::STATE_PRIVATE);
|
|
}
|
|
return $this;
|
|
}
|
|
|
|
/**
|
|
* Advanced way to set cache control header to a cacheable state.
|
|
* Indicates that the response may be cached by any cache. (eg: CDNs, Proxies, Web browsers).
|
|
* Needs either `setMaxAge()` or the `$maxAge` method argument in order to activate caching.
|
|
*
|
|
* The resulting cache-control headers will be chosen from the 'private' set of directives.
|
|
*
|
|
* @see https://docs.silverstripe.org/en/developer_guides/performance/http_cache_headers/
|
|
* @param bool $force Force the cache to public even if it's private, unless it's been forced private
|
|
* @param int $maxAge Shortcut for `setMaxAge()`, which is required to actually enable the cache.
|
|
* @return $this
|
|
*/
|
|
public function publicCache($force = false, $maxAge = null)
|
|
{
|
|
// Only execute this if its forcing level is high enough
|
|
if ($this->applyChangeLevel(self::LEVEL_PUBLIC, $force)) {
|
|
$this->setState(self::STATE_PUBLIC);
|
|
}
|
|
|
|
if (!is_null($maxAge)) {
|
|
$this->setMaxAge($maxAge);
|
|
}
|
|
|
|
return $this;
|
|
}
|
|
|
|
/**
|
|
* Generate all headers to add to this object
|
|
*
|
|
* @param HTTPResponse $response
|
|
*
|
|
* @return $this
|
|
*/
|
|
public function applyToResponse($response)
|
|
{
|
|
$headers = $this->generateHeadersFor($response);
|
|
foreach ($headers as $name => $value) {
|
|
if (!$response->getHeader($name)) {
|
|
$response->addHeader($name, $value);
|
|
}
|
|
}
|
|
return $this;
|
|
}
|
|
|
|
/**
|
|
* Generate the cache header
|
|
*
|
|
* @return string
|
|
*/
|
|
protected function generateCacheHeader()
|
|
{
|
|
$cacheControl = [];
|
|
foreach ($this->getDirectives() as $directive => $value) {
|
|
if ($value === true) {
|
|
$cacheControl[] = $directive;
|
|
} else {
|
|
$cacheControl[] = $directive . '=' . $value;
|
|
}
|
|
}
|
|
return implode(', ', $cacheControl);
|
|
}
|
|
|
|
/**
|
|
* Generate all headers to output
|
|
*
|
|
* @param HTTPResponse $response
|
|
* @return array
|
|
*/
|
|
public function generateHeadersFor(HTTPResponse $response)
|
|
{
|
|
return array_filter([
|
|
'Last-Modified' => $this->generateLastModifiedHeader(),
|
|
'Vary' => $this->generateVaryHeader($response),
|
|
'Cache-Control' => $this->generateCacheHeader(),
|
|
'Expires' => $this->generateExpiresHeader(),
|
|
]);
|
|
}
|
|
|
|
/**
|
|
* Reset registered http cache control and force a fresh instance to be built
|
|
*/
|
|
public static function reset()
|
|
{
|
|
Injector::inst()->unregisterNamedObject(__CLASS__);
|
|
}
|
|
|
|
/**
|
|
* @return int
|
|
*/
|
|
protected function getForcingLevel()
|
|
{
|
|
if (isset($this->forcingLevel)) {
|
|
return $this->forcingLevel;
|
|
}
|
|
return $this->config()->get('defaultForcingLevel');
|
|
}
|
|
|
|
/**
|
|
* Generate vary http header
|
|
*
|
|
* @param HTTPResponse $response
|
|
* @return string|null
|
|
*/
|
|
protected function generateVaryHeader(HTTPResponse $response)
|
|
{
|
|
// split the current vary header into it's parts and merge it with the config settings
|
|
// to create a list of unique vary values
|
|
$vary = $this->getVary();
|
|
if ($response->getHeader('Vary')) {
|
|
$vary = $this->combineVary($vary, $response->getHeader('Vary'));
|
|
}
|
|
if ($vary) {
|
|
return implode(', ', $vary);
|
|
}
|
|
return null;
|
|
}
|
|
|
|
/**
|
|
* Generate Last-Modified header
|
|
*
|
|
* @return string|null
|
|
*/
|
|
protected function generateLastModifiedHeader()
|
|
{
|
|
if (!$this->modificationDate) {
|
|
return null;
|
|
}
|
|
return gmdate('D, d M Y H:i:s', $this->modificationDate) . ' GMT';
|
|
}
|
|
|
|
/**
|
|
* Generate Expires http header
|
|
*
|
|
* @return null|string
|
|
*/
|
|
protected function generateExpiresHeader()
|
|
{
|
|
$maxAge = $this->getDirective('max-age');
|
|
if ($maxAge === false) {
|
|
return null;
|
|
}
|
|
|
|
// Add now to max-age to generate expires
|
|
$expires = DBDatetime::now()->getTimestamp() + $maxAge;
|
|
return gmdate('D, d M Y H:i:s', $expires) . ' GMT';
|
|
}
|
|
|
|
/**
|
|
* Update state based on current request and response objects
|
|
*
|
|
* @param HTTPRequest $request
|
|
* @param HTTPResponse $response
|
|
*/
|
|
protected function augmentState(HTTPRequest $request, HTTPResponse $response)
|
|
{
|
|
// Errors disable cache (unless some errors are cached intentionally by usercode)
|
|
if ($response->isError() || $response->isRedirect()) {
|
|
// Even if publicCache(true) is specified, errors will be uncacheable
|
|
$this->disableCache(true);
|
|
} elseif ($request->getSession()->getAll()) {
|
|
// If sessions exist we assume that the responses should not be cached by CDNs / proxies as we are
|
|
// likely to be supplying information relevant to the current user only
|
|
|
|
// Don't force in case user code chooses to opt in to public caching
|
|
$this->privateCache();
|
|
}
|
|
}
|
|
}
|