Complex classes like FileCache 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 FileCache, and based on these observations, apply Extract Interface, too.
1 | <?php |
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21 | class FileCache implements CacheInterface |
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22 | { |
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23 | /** |
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24 | * @var string control characters for keys, reserved by PSR-16 |
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25 | */ |
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26 | const PSR16_RESERVED = '/\{|\}|\(|\)|\/|\\\\|\@|\:/u'; |
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27 | |||
28 | /** |
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29 | * @var string |
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30 | */ |
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31 | private $cache_path; |
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32 | |||
33 | /** |
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34 | * @var int |
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35 | */ |
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36 | private $default_ttl; |
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37 | |||
38 | /** |
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39 | * @var int |
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40 | */ |
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41 | private $dir_mode; |
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42 | |||
43 | /** |
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44 | * @var int |
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45 | */ |
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46 | private $file_mode; |
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47 | |||
48 | /** |
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49 | * @param string $cache_path absolute root path of cache-file folder |
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50 | * @param int $default_ttl default time-to-live (in seconds) |
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51 | * @param int $dir_mode permission mode for created dirs |
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52 | * @param int $file_mode permission mode for created files |
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53 | */ |
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54 | 14 | public function __construct($cache_path, $default_ttl, $dir_mode = 0775, $file_mode = 0664) |
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76 | |||
77 | 12 | public function get($key, $default = null) |
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111 | |||
112 | 13 | public function set($key, $value, $ttl = null) |
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151 | |||
152 | 2 | public function delete($key) |
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156 | |||
157 | 14 | public function clear() |
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171 | |||
172 | 2 | public function getMultiple($keys, $default = null) |
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186 | |||
187 | 2 | public function setMultiple($values, $ttl = null) |
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202 | |||
203 | 1 | public function deleteMultiple($keys) |
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214 | |||
215 | 1 | public function has($key) |
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219 | |||
220 | 2 | public function increment($key, $step = 1) |
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244 | |||
245 | 1 | public function decrement($key, $step = 1) |
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249 | |||
250 | /** |
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251 | * Clean up expired cache-files. |
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252 | * |
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253 | * This method is outside the scope of the PSR-16 cache concept, and is specific to |
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254 | * this implementation, being a file-cache. |
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255 | * |
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256 | * In scenarios with dynamic keys (such as Session IDs) you should call this method |
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257 | * periodically - for example from a scheduled daily cron-job. |
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258 | * |
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259 | * @return void |
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260 | */ |
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261 | 1 | public function cleanExpired() |
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273 | |||
274 | /** |
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275 | * For a given cache key, obtain the absolute file path |
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276 | * |
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277 | * @param string $key |
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278 | * |
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279 | * @return string absolute path to cache-file |
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280 | * |
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281 | * @throws InvalidArgumentException if the specified key contains a character reserved by PSR-16 |
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282 | */ |
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283 | 14 | protected function getPath($key) |
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297 | |||
298 | /** |
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299 | * @return int current timestamp |
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300 | */ |
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301 | 14 | protected function getTime() |
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305 | |||
306 | /** |
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307 | * @return Generator|string[] |
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308 | */ |
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309 | 14 | protected function listPaths() |
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326 | |||
327 | /** |
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328 | * @param string $key |
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329 | * |
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330 | * @throws InvalidArgumentException |
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331 | */ |
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332 | 14 | protected function validateKey($key) |
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338 | |||
339 | /** |
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340 | * Recursively create directories and apply permission mask |
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341 | * |
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342 | * @param string $path absolute directory path |
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343 | */ |
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344 | 14 | private function mkdir($path) |
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355 | } |
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356 |
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