Complex classes like CacheData 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 CacheData, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 9 | class CacheData { |
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| 10 | const CACHEDATA_TYPE_CALLBACK = 'callback'; |
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| 11 | const CACHEDATA_TYPE_RECURSION = 'recursion'; |
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| 12 | const CACHEDATA_TYPE_RECURSION_DATA = 'recursiondata'; |
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| 13 | const CACHEDATA_TYPE_DATA = 'data'; |
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| 14 | |||
| 15 | /** |
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| 16 | * |
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| 17 | * @var CacheKey |
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| 18 | */ |
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| 19 | public $key; |
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| 20 | |||
| 21 | /** |
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| 22 | * Lifetime: how long this cache should live. It's up to the storage implementation |
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| 23 | * the details of how this will be obeyed, if at all. |
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| 24 | * @var integer |
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| 25 | */ |
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| 26 | public $lifetime; |
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| 27 | |||
| 28 | /** |
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| 29 | * This is a storage of dependencies for this cache. This is stored here as |
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| 30 | * the russian doll model will automatically push up dependencies. In the end |
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| 31 | * this will probably be used by the storage for easy invalidation. |
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| 32 | * |
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| 33 | * @var array:CacheKey |
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| 34 | */ |
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| 35 | public $dependencies = array(); |
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| 36 | |||
| 37 | /** |
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| 38 | * The actual cached data |
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| 39 | * @var array |
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| 40 | */ |
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| 41 | public $data = array(); |
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| 42 | |||
| 43 | private $dependenciesHash = ''; |
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| 44 | |||
| 45 | public function __construct(CacheKey $ck, $data = null) { |
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| 52 | |||
| 53 | /** |
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| 54 | * |
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| 55 | * @param CacheKey $ck |
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| 56 | * @return CacheData |
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| 57 | */ |
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| 58 | public function setKey(CacheKey $ck) { |
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| 62 | |||
| 63 | /** |
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| 64 | * |
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| 65 | * @param unknown $callback |
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| 66 | * @return CacheData |
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| 67 | */ |
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| 68 | public function appendCallback(callable $callback) { |
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| 72 | |||
| 73 | /** |
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| 74 | * |
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| 75 | * @param CacheData $cd |
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| 76 | * @return CacheData |
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| 77 | */ |
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| 78 | public function mergeDependencies(CacheData $cd) { |
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| 82 | |||
| 83 | public function clearDependenciesHash() { |
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| 86 | |||
| 87 | /** |
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| 88 | * Checks if dependencies are still fresh. |
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| 89 | * @param CacheAbstract $cache |
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| 90 | * @return boolean |
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| 91 | */ |
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| 92 | public function checkUpdateToDate(CacheAbstract $cache) { |
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| 102 | |||
| 103 | /** |
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| 104 | * Init dependencies. If increment is not supported by backend return 0. |
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| 105 | * |
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| 106 | * @param CacheAbstract $cache |
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| 107 | * @param CacheKey $k |
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| 108 | * @return integer |
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| 109 | */ |
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| 110 | public function dependencyInit(CacheAbstract $cache, CacheKey $k) { |
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| 118 | |||
| 119 | /** |
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| 120 | * Get a fresh hash based on dependencies. Does not update the current hash. |
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| 121 | * @param CacheAbstract $cache |
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| 122 | * @return string |
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| 123 | */ |
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| 124 | public function generateDependenciesHash(CacheAbstract $cache) { |
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| 131 | |||
| 132 | public function updateDependenciesHash(CacheAbstract $cache) { |
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| 136 | |||
| 137 | public function updateDependenciesHashIfNull(CacheAbstract $cache) { |
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| 143 | |||
| 144 | public function getKey() { |
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| 147 | |||
| 148 | public function getDependenciesHash() { |
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| 151 | |||
| 152 | public function getDependencies() { |
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| 155 | |||
| 156 | /** |
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| 157 | * |
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| 158 | * @param mixed $data Any kind of data you want to store. usually strings. |
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| 159 | * @return CacheData |
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| 160 | */ |
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| 161 | public function appendData($data) { |
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| 167 | |||
| 168 | /** |
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| 169 | * Convenience function. Returns the first data self::CACHEDATA_TYPE_DATA that you |
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| 170 | * stored. Returns null if there is none. |
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| 171 | * |
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| 172 | * @return any|NULL |
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| 173 | */ |
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| 174 | public function getFirstData() { |
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| 182 | |||
| 183 | public function appendRecursion(CacheKey $k) { |
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| 191 | |||
| 192 | public function appendRecursionData(CacheData $d) { |
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| 203 | |||
| 204 | /** |
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| 205 | * Adds a dependency |
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| 206 | * @param CacheKey $k |
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| 207 | * @return CacheData This |
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| 208 | */ |
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| 209 | public function addDependency(CacheKey $k) { |
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| 214 | |||
| 215 | /** |
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| 216 | * Adds a dependency |
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| 217 | * @param array<CacheKey> $k |
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| 218 | * @return CacheData This |
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| 219 | */ |
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| 220 | public function addDependencies(array $deps) { |
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| 226 | |||
| 227 | /** |
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| 228 | * Sets the list of dependencies and updates the dependency hash |
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| 229 | * |
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| 230 | * @param array<CacheKey> $deps |
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| 231 | * @param CacheAbstract $cache |
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| 232 | * @return CacheData |
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| 233 | */ |
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| 234 | public function setDependencies(array $deps, CacheAbstract $cache) { |
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| 242 | |||
| 243 | /** |
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| 244 | * |
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| 245 | * @param integer $lifetime |
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| 246 | * @return CacheData |
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| 247 | */ |
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| 248 | public function setLifetime($lifetime) { |
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| 252 | |||
| 253 | /** |
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| 254 | * Checks if a set of keys clashes with the ones used here. |
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| 255 | * @param CacheKey $k |
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| 256 | * @return boolean True if they match and there is a clash |
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| 257 | */ |
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| 258 | public function checkClash(CacheKey $k) { |
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| 261 | |||
| 262 | /** |
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| 263 | * Converts this data to a string that can output. This is not a hash |
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| 264 | * key or a serialization, but an actual render for humans. |
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| 265 | * |
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| 266 | * @throws Exceptions\NotCachedException |
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| 267 | */ |
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| 268 | public function stringify(CacheAbstract $c, $recurse = true) { |
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| 298 | |||
| 299 | /** |
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| 300 | * Serialize this object to a string so we can easily store. |
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| 301 | * |
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| 302 | * @return string |
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| 303 | */ |
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| 304 | public function serialize() { |
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| 307 | |||
| 308 | /** |
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| 309 | * Unserializes data and returns a new CacheData. This is what you |
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| 310 | * should use to get the object data from the storage. |
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| 311 | * |
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| 312 | * @param string $data |
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| 313 | * @return CacheData |
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| 314 | */ |
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| 315 | static public function unserialize($data) { |
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| 318 | } |
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| 319 |