3 namespace Drupal\Core\Cache;
6 * Defines a memory cache implementation.
8 * Stores cache items in memory using a PHP array.
10 * Should be used for unit tests and specialist use-cases only, does not
11 * store cached items between requests.
13 * The functions ::prepareItem()/::set() use unserialize()/serialize(). It
14 * behaves as an external cache backend to avoid changing the cached data by
15 * reference. In ::prepareItem(), the object is not modified by the call to
16 * unserialize() because we make a clone of it.
20 class MemoryBackend implements CacheBackendInterface, CacheTagsInvalidatorInterface {
23 * Array to store cache objects.
25 protected $cache = [];
30 public function get($cid, $allow_invalid = FALSE) {
31 if (isset($this->cache[$cid])) {
32 return $this->prepareItem($this->cache[$cid], $allow_invalid);
42 public function getMultiple(&$cids, $allow_invalid = FALSE) {
45 $items = array_intersect_key($this->cache, array_flip($cids));
47 foreach ($items as $item) {
48 $item = $this->prepareItem($item, $allow_invalid);
50 $ret[$item->cid] = $item;
54 $cids = array_diff($cids, array_keys($ret));
60 * Prepares a cached item.
62 * Checks that items are either permanent or did not expire, and returns data
65 * @param object $cache
66 * An item loaded from cache_get() or cache_get_multiple().
67 * @param bool $allow_invalid
68 * (optional) If TRUE, cache items may be returned even if they have expired
69 * or been invalidated.
72 * The item with data as appropriate or FALSE if there is no
75 protected function prepareItem($cache, $allow_invalid) {
76 if (!isset($cache->data)) {
79 // The object passed into this function is the one stored in $this->cache.
80 // We must clone it as part of the preparation step so that the actual
81 // cache object is not affected by the unserialize() call or other
82 // manipulations of the returned object.
84 $prepared = clone $cache;
85 $prepared->data = unserialize($prepared->data);
88 $prepared->valid = $prepared->expire == Cache::PERMANENT || $prepared->expire >= $this->getRequestTime();
90 if (!$allow_invalid && !$prepared->valid) {
100 public function set($cid, $data, $expire = Cache::PERMANENT, array $tags = []) {
101 assert('\Drupal\Component\Assertion\Inspector::assertAllStrings($tags)', 'Cache Tags must be strings.');
102 $tags = array_unique($tags);
103 // Sort the cache tags so that they are stored consistently in the database.
105 $this->cache[$cid] = (object) [
107 'data' => serialize($data),
108 'created' => $this->getRequestTime(),
117 public function setMultiple(array $items = []) {
118 foreach ($items as $cid => $item) {
119 $this->set($cid, $item['data'], isset($item['expire']) ? $item['expire'] : CacheBackendInterface::CACHE_PERMANENT, isset($item['tags']) ? $item['tags'] : []);
126 public function delete($cid) {
127 unset($this->cache[$cid]);
133 public function deleteMultiple(array $cids) {
134 $this->cache = array_diff_key($this->cache, array_flip($cids));
140 public function deleteAll() {
147 public function invalidate($cid) {
148 if (isset($this->cache[$cid])) {
149 $this->cache[$cid]->expire = $this->getRequestTime() - 1;
156 public function invalidateMultiple(array $cids) {
157 foreach ($cids as $cid) {
158 if (isset($this->cache[$cid])) {
159 $this->cache[$cid]->expire = $this->getRequestTime() - 1;
167 public function invalidateTags(array $tags) {
168 foreach ($this->cache as $cid => $item) {
169 if (array_intersect($tags, $item->tags)) {
170 $this->cache[$cid]->expire = $this->getRequestTime() - 1;
178 public function invalidateAll() {
179 foreach ($this->cache as $cid => $item) {
180 $this->cache[$cid]->expire = $this->getRequestTime() - 1;
187 public function garbageCollection() {
193 public function removeBin() {
198 * Wrapper method for REQUEST_TIME constant.
202 protected function getRequestTime() {
203 return defined('REQUEST_TIME') ? REQUEST_TIME : (int) $_SERVER['REQUEST_TIME'];
207 * Prevents data stored in memory backends from being serialized.
209 public function __sleep() {
214 * Reset statically cached variables.
216 * This is only used by tests.
218 public function reset() {