Complex classes like Cache often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Cache, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 20 | class Cache implements iCache |
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| 21 | { |
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| 22 | |||
| 23 | /** |
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| 24 | * @var iAdapter |
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| 25 | */ |
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| 26 | protected $adapter; |
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| 27 | |||
| 28 | /** |
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| 29 | * @var iSerializer |
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| 30 | */ |
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| 31 | protected $serializer; |
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| 32 | |||
| 33 | /** |
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| 34 | * @var string |
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| 35 | */ |
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| 36 | protected $prefix = ''; |
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| 37 | |||
| 38 | /** |
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| 39 | * @var bool |
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| 40 | */ |
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| 41 | protected $isReady = false; |
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| 42 | |||
| 43 | /** |
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| 44 | * @var bool |
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| 45 | */ |
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| 46 | protected $isActive = true; |
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| 47 | |||
| 48 | /** |
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| 49 | * @var mixed no cache, if admin-session is set |
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| 50 | */ |
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| 51 | protected $isAdminSession = false; |
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| 52 | |||
| 53 | /** |
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| 54 | * @var array |
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| 55 | */ |
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| 56 | protected static $STATIC_CACHE = array(); |
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| 57 | |||
| 58 | /** |
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| 59 | * @var array |
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| 60 | */ |
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| 61 | protected static $STATIC_CACHE_EXPIRE = array(); |
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| 62 | |||
| 63 | /** |
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| 64 | * @var array |
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| 65 | */ |
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| 66 | protected static $STATIC_CACHE_COUNTER = array(); |
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| 67 | |||
| 68 | /** |
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| 69 | * @var int |
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| 70 | */ |
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| 71 | protected $staticCacheHitCounter = 10; |
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| 72 | |||
| 73 | /** |
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| 74 | * __construct |
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| 75 | * |
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| 76 | * @param null|iAdapter $adapter |
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| 77 | * @param null|iSerializer $serializer |
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| 78 | * @param boolean $checkForUser check for dev-ip or if cms-user is logged-in |
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| 79 | * @param boolean $cacheEnabled false will disable the cache (use it e.g. for global settings) |
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| 80 | * @param string|boolean $isAdminSession set a user-id, if the user is a admin (so we can disable cache for this |
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| 81 | * user) |
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| 82 | */ |
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| 83 | 51 | public function __construct(iAdapter $adapter = null, iSerializer $serializer = null, $checkForUser = true, $cacheEnabled = true, $isAdminSession = false) |
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| 139 | |||
| 140 | /** |
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| 141 | * enable / disable the cache |
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| 142 | * |
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| 143 | * @param boolean $isActive |
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| 144 | */ |
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| 145 | 51 | public function setActive($isActive) |
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| 149 | |||
| 150 | /** |
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| 151 | * check if the current use is a admin || dev || server == client |
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| 152 | * |
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| 153 | * @return bool |
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| 154 | */ |
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| 155 | public function isCacheActiveForTheCurrentUser() |
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| 183 | |||
| 184 | /** |
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| 185 | * returns the IP address of the client |
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| 186 | * |
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| 187 | * @param bool $trust_proxy_headers Whether or not to trust the |
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| 188 | * proxy headers HTTP_CLIENT_IP |
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| 189 | * and HTTP_X_FORWARDED_FOR. ONLY |
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| 190 | * use if your $_SERVER is behind a |
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| 191 | * proxy that sets these values |
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| 192 | * |
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| 193 | * @return string |
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| 194 | */ |
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| 195 | protected function getClientIp($trust_proxy_headers = false) |
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| 213 | |||
| 214 | /** |
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| 215 | * Check for local developer. |
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| 216 | * |
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| 217 | * @return bool |
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| 218 | */ |
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| 219 | protected function checkForDev() |
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| 248 | |||
| 249 | /** |
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| 250 | * Set the default-prefix via "SERVER"-var + "SESSION"-language. |
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| 251 | */ |
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| 252 | 51 | protected function getTheDefaultPrefix() |
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| 260 | |||
| 261 | /** |
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| 262 | * Auto-connect to the available cache-system on the server. |
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| 263 | * |
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| 264 | * @return iAdapter |
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| 265 | */ |
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| 266 | protected function autoConnectToAvailableCacheSystem() |
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| 414 | |||
| 415 | /** |
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| 416 | * Set "isReady" state. |
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| 417 | * |
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| 418 | * @param boolean $isReady |
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| 419 | */ |
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| 420 | 51 | protected function setCacheIsReady($isReady) |
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| 424 | |||
| 425 | /** |
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| 426 | * Get the "isReady" state. |
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| 427 | * |
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| 428 | * @return boolean |
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| 429 | */ |
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| 430 | 4 | public function getCacheIsReady() |
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| 434 | |||
| 435 | /** |
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| 436 | * Get cached-item by key. |
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| 437 | * |
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| 438 | * @param string $key |
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| 439 | * @param int $forceStaticCacheHitCounter |
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| 440 | * |
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| 441 | * @return mixed |
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| 442 | */ |
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| 443 | 22 | public function getItem($key, $forceStaticCacheHitCounter = 0) |
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| 501 | |||
| 502 | /** |
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| 503 | * Calculate store-key (prefix + $rawKey). |
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| 504 | * |
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| 505 | * @param string $rawKey |
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| 506 | * |
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| 507 | * @return string |
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| 508 | */ |
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| 509 | 42 | protected function calculateStoreKey($rawKey) |
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| 519 | |||
| 520 | /** |
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| 521 | * Clean store-key (required e.g. for the "File"-Adapter). |
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| 522 | * |
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| 523 | * @param string $str |
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| 524 | * |
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| 525 | * @return string |
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| 526 | */ |
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| 527 | 8 | protected function cleanStoreKey($str) |
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| 553 | |||
| 554 | /** |
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| 555 | * Get the prefix. |
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| 556 | * |
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| 557 | * @return string |
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| 558 | */ |
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| 559 | 42 | public function getPrefix() |
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| 563 | |||
| 564 | /** |
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| 565 | * !!! Set the prefix. !!! |
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| 566 | * |
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| 567 | * WARNING: Do not use if you don't know what you do. Because this will overwrite the default prefix. |
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| 568 | * |
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| 569 | * @param string $prefix |
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| 570 | */ |
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| 571 | 51 | public function setPrefix($prefix) |
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| 575 | |||
| 576 | /** |
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| 577 | * Get the current value, when the static cache is used. |
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| 578 | * |
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| 579 | * @return int |
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| 580 | */ |
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| 581 | public function getStaticCacheHitCounter() |
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| 585 | |||
| 586 | /** |
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| 587 | * Set the static-hit-counter: Who often do we hit the cache, before we use static cache? |
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| 588 | * |
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| 589 | * @param int $staticCacheHitCounter |
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| 590 | */ |
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| 591 | public function setStaticCacheHitCounter($staticCacheHitCounter) |
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| 595 | |||
| 596 | /** |
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| 597 | * Set cache-item by key => value + date. |
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| 598 | * |
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| 599 | * @param string $key |
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| 600 | * @param mixed $value |
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| 601 | * @param \DateTime $date <p>If the date is in the past, we will remove the existing cache-item.</p> |
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| 602 | * |
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| 603 | * @return boolean |
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| 604 | * @throws \Exception |
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| 605 | */ |
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| 606 | 8 | public function setItemToDate($key, $value, \DateTime $date) |
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| 618 | |||
| 619 | /** |
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| 620 | * Set cache-item by key => value + ttl. |
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| 621 | * |
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| 622 | * @param string $key |
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| 623 | * @param mixed $value |
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| 624 | * @param null|int|\DateInterval $ttl |
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| 625 | * |
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| 626 | * @return bool |
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| 627 | */ |
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| 628 | 23 | public function setItem($key, $value, $ttl = 0) |
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| 661 | |||
| 662 | /** |
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| 663 | * Remove a cached-item. |
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| 664 | * |
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| 665 | * @param string $key |
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| 666 | * |
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| 667 | * @return bool |
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| 668 | */ |
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| 669 | 3 | public function removeItem($key) |
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| 692 | |||
| 693 | /** |
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| 694 | * Remove all cached-items. |
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| 695 | * |
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| 696 | * @return bool |
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| 697 | */ |
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| 698 | 1 | public function removeAll() |
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| 713 | |||
| 714 | /** |
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| 715 | * Check if cached-item exists. |
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| 716 | * |
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| 717 | * @param string $key |
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| 718 | * |
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| 719 | * @return boolean |
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| 720 | */ |
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| 721 | 10 | public function existsItem($key) |
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| 736 | |||
| 737 | /** |
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| 738 | * @param string $storeKey |
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| 739 | * |
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| 740 | * @return bool |
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| 741 | */ |
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| 742 | 26 | protected function checkForStaticCache($storeKey) |
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| 758 | |||
| 759 | /** |
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| 760 | * Get the current adapter class-name. |
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| 761 | * |
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| 762 | * @return string |
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| 763 | */ |
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| 764 | 2 | public function getUsedAdapterClassName() |
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| 768 | |||
| 769 | /** |
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| 770 | * Get the current serializer class-name. |
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| 771 | * |
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| 772 | * @return string |
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| 773 | */ |
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| 774 | 2 | public function getUsedSerializerClassName() |
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| 778 | } |
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| 779 |
Instead of super-globals, we recommend to explicitly inject the dependencies of your class. This makes your code less dependent on global state and it becomes generally more testable: