CASTrait.php 1.4 KB

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  1. <?php
  2. /**
  3. * @copyright Copyright (c) 2016, ownCloud, Inc.
  4. *
  5. * @author Robin Appelman <robin@icewind.nl>
  6. *
  7. * @license AGPL-3.0
  8. *
  9. * This code is free software: you can redistribute it and/or modify
  10. * it under the terms of the GNU Affero General Public License, version 3,
  11. * as published by the Free Software Foundation.
  12. *
  13. * This program is distributed in the hope that it will be useful,
  14. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16. * GNU Affero General Public License for more details.
  17. *
  18. * You should have received a copy of the GNU Affero General Public License, version 3,
  19. * along with this program. If not, see <http://www.gnu.org/licenses/>
  20. *
  21. */
  22. namespace OC\Memcache;
  23. trait CASTrait {
  24. abstract public function get($key);
  25. abstract public function set($key, $value, $ttl = 0);
  26. abstract public function remove($key);
  27. abstract public function add($key, $value, $ttl = 0);
  28. /**
  29. * Compare and set
  30. *
  31. * @param string $key
  32. * @param mixed $old
  33. * @param mixed $new
  34. * @return bool
  35. */
  36. public function cas($key, $old, $new) {
  37. //no native cas, emulate with locking
  38. if ($this->add($key . '_lock', true)) {
  39. if ($this->get($key) === $old) {
  40. $this->set($key, $new);
  41. $this->remove($key . '_lock');
  42. return true;
  43. } else {
  44. $this->remove($key . '_lock');
  45. return false;
  46. }
  47. } else {
  48. return false;
  49. }
  50. }
  51. }