MemoryBackend.php 5.2 KB
Newer Older
1 2 3 4
<?php

namespace Drupal\Core\Cache;

5 6
use Drupal\Component\Assertion\Inspector;

7 8 9 10 11 12 13 14
/**
 * Defines a memory cache implementation.
 *
 * Stores cache items in memory using a PHP array.
 *
 * Should be used for unit tests and specialist use-cases only, does not
 * store cached items between requests.
 *
15 16 17 18 19
 * The functions ::prepareItem()/::set() use unserialize()/serialize(). It
 * behaves as an external cache backend to avoid changing the cached data by
 * reference. In ::prepareItem(), the object is not modified by the call to
 * unserialize() because we make a clone of it.
 *
20
 * @ingroup cache
21
 */
22
class MemoryBackend implements CacheBackendInterface, CacheTagsInvalidatorInterface {
23 24 25 26

  /**
   * Array to store cache objects.
   */
27
  protected $cache = [];
28 29

  /**
30
   * {@inheritdoc}
31
   */
32
  public function get($cid, $allow_invalid = FALSE) {
33
    if (isset($this->cache[$cid])) {
34
      return $this->prepareItem($this->cache[$cid], $allow_invalid);
35 36 37 38 39 40 41
    }
    else {
      return FALSE;
    }
  }

  /**
42
   * {@inheritdoc}
43
   */
44
  public function getMultiple(&$cids, $allow_invalid = FALSE) {
45
    $ret = [];
46 47 48 49

    $items = array_intersect_key($this->cache, array_flip($cids));

    foreach ($items as $item) {
50
      $item = $this->prepareItem($item, $allow_invalid);
51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66
      if ($item) {
        $ret[$item->cid] = $item;
      }
    }

    $cids = array_diff($cids, array_keys($ret));

    return $ret;
  }

  /**
   * Prepares a cached item.
   *
   * Checks that items are either permanent or did not expire, and returns data
   * as appropriate.
   *
67
   * @param object $cache
68
   *   An item loaded from cache_get() or cache_get_multiple().
69 70 71
   * @param bool $allow_invalid
   *   (optional) If TRUE, cache items may be returned even if they have expired
   *   or been invalidated.
72 73 74 75 76
   *
   * @return mixed
   *   The item with data as appropriate or FALSE if there is no
   *   valid item to load.
   */
77
  protected function prepareItem($cache, $allow_invalid) {
78 79 80
    if (!isset($cache->data)) {
      return FALSE;
    }
81 82 83 84 85 86 87
    // The object passed into this function is the one stored in $this->cache.
    // We must clone it as part of the preparation step so that the actual
    // cache object is not affected by the unserialize() call or other
    // manipulations of the returned object.

    $prepared = clone $cache;
    $prepared->data = unserialize($prepared->data);
88

89
    // Check expire time.
90
    $prepared->valid = $prepared->expire == Cache::PERMANENT || $prepared->expire >= $this->getRequestTime();
91

92
    if (!$allow_invalid && !$prepared->valid) {
93 94 95
      return FALSE;
    }

96
    return $prepared;
97 98 99
  }

  /**
100
   * {@inheritdoc}
101
   */
102
  public function set($cid, $data, $expire = Cache::PERMANENT, array $tags = []) {
103
    assert(Inspector::assertAllStrings($tags), 'Cache Tags must be strings.');
104 105 106
    $tags = array_unique($tags);
    // Sort the cache tags so that they are stored consistently in the database.
    sort($tags);
107
    $this->cache[$cid] = (object) [
108
      'cid' => $cid,
109
      'data' => serialize($data),
110
      'created' => $this->getRequestTime(),
111
      'expire' => $expire,
112
      'tags' => $tags,
113
    ];
114 115
  }

116 117 118
  /**
   * {@inheritdoc}
   */
119
  public function setMultiple(array $items = []) {
120
    foreach ($items as $cid => $item) {
121
      $this->set($cid, $item['data'], isset($item['expire']) ? $item['expire'] : CacheBackendInterface::CACHE_PERMANENT, isset($item['tags']) ? $item['tags'] : []);
122 123 124
    }
  }

125
  /**
126
   * {@inheritdoc}
127 128 129 130 131 132
   */
  public function delete($cid) {
    unset($this->cache[$cid]);
  }

  /**
133
   * {@inheritdoc}
134 135 136 137 138
   */
  public function deleteMultiple(array $cids) {
    $this->cache = array_diff_key($this->cache, array_flip($cids));
  }

139
  /**
140
   * {@inheritdoc}
141 142
   */
  public function deleteAll() {
143
    $this->cache = [];
144 145 146
  }

  /**
147
   * {@inheritdoc}
148 149
   */
  public function invalidate($cid) {
150
    if (isset($this->cache[$cid])) {
151
      $this->cache[$cid]->expire = $this->getRequestTime() - 1;
152
    }
153 154 155
  }

  /**
156
   * {@inheritdoc}
157
   */
158
  public function invalidateMultiple(array $cids) {
159 160
    $items = array_intersect_key($this->cache, array_flip($cids));
    foreach ($items as $cid => $item) {
161
      $this->cache[$cid]->expire = $this->getRequestTime() - 1;
162 163 164 165
    }
  }

  /**
166
   * {@inheritdoc}
167 168 169
   */
  public function invalidateTags(array $tags) {
    foreach ($this->cache as $cid => $item) {
170
      if (array_intersect($tags, $item->tags)) {
171
        $this->cache[$cid]->expire = $this->getRequestTime() - 1;
172 173 174 175 176
      }
    }
  }

  /**
177
   * {@inheritdoc}
178 179 180
   */
  public function invalidateAll() {
    foreach ($this->cache as $cid => $item) {
181
      $this->cache[$cid]->expire = $this->getRequestTime() - 1;
182 183 184
    }
  }

185
  /**
186
   * {@inheritdoc}
187 188 189
   */
  public function garbageCollection() {
  }
190

191 192 193
  /**
   * {@inheritdoc}
   */
194 195 196
  public function removeBin() {
    $this->cache = [];
  }
197

198 199 200 201 202 203 204 205 206
  /**
   * Wrapper method for REQUEST_TIME constant.
   *
   * @return int
   */
  protected function getRequestTime() {
    return defined('REQUEST_TIME') ? REQUEST_TIME : (int) $_SERVER['REQUEST_TIME'];
  }

207 208 209 210 211 212 213
  /**
   * Prevents data stored in memory backends from being serialized.
   */
  public function __sleep() {
    return [];
  }

214 215 216 217 218 219 220 221 222
  /**
   * Reset statically cached variables.
   *
   * This is only used by tests.
   */
  public function reset() {
    $this->cache = [];
  }

223
}