Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like FileRepository 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 FileRepository, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 30 | class FileRepository implements RepositoryInterface |
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| 31 | { |
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| 32 | /** |
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| 33 | * File where all rates are persisted. |
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| 34 | * |
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| 35 | * @var string |
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| 36 | */ |
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| 37 | protected $pathToFile; |
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| 38 | |||
| 39 | /** |
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| 40 | * Collection of loaded rates. |
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| 41 | * |
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| 42 | * @var array |
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| 43 | */ |
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| 44 | protected $rates; |
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| 45 | |||
| 46 | /** |
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| 47 | * Collection of latest rates (to speed up search process). |
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| 48 | * |
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| 49 | * @var array |
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| 50 | */ |
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| 51 | protected $latest; |
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| 52 | |||
| 53 | 10 | public function __construct($pathToFile) |
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| 59 | |||
| 60 | /** |
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| 61 | * {@inheritdoc} |
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| 62 | */ |
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| 63 | 10 | public function save(array $rates) |
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| 89 | |||
| 90 | /** |
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| 91 | * {@inheritdoc} |
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| 92 | */ |
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| 93 | 2 | public function delete(array $rates) |
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| 104 | |||
| 105 | /** |
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| 106 | * {@inheritdoc} |
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| 107 | */ |
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| 108 | 4 | public function has($sourceName, $currencyCode, \DateTime $date = null, $rateType = RateType::DEFAULT) |
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| 116 | |||
| 117 | /** |
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| 118 | * {@inheritdoc} |
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| 119 | */ |
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| 120 | 2 | public function get($sourceName, $currencyCode, \DateTime $date = null, $rateType = RateType::DEFAULT) |
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| 132 | |||
| 133 | /** |
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| 134 | * {@inheritdoc} |
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| 135 | */ |
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| 136 | 2 | public function latest($sourceName, $currencyCode, $rateType = RateType::DEFAULT) |
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| 156 | |||
| 157 | /** |
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| 158 | * {@inheritdoc} |
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| 159 | */ |
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| 160 | 4 | public function all(array $criteria = array()) |
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| 180 | |||
| 181 | /** |
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| 182 | * {@inheritdoc} |
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| 183 | */ |
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| 184 | 2 | public function count() |
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| 188 | |||
| 189 | /** |
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| 190 | * Load all rates from file. |
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| 191 | * |
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| 192 | * @return RateInterface[] |
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| 193 | */ |
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| 194 | 10 | protected function load() |
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| 224 | |||
| 225 | /** |
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| 226 | * Builds rate key to speed up search. |
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| 227 | * |
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| 228 | * @param string|null|RateInterface $currencyCode |
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| 229 | * @param \DateTime|null $date |
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| 230 | * @param string|null $rateType |
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| 231 | * @param string|null $sourceName |
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| 232 | * @return string |
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| 233 | */ |
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| 234 | 10 | protected function getRateKey($currencyCode = null, $date = null, $rateType = null, $sourceName = null) |
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| 249 | |||
| 250 | /** |
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| 251 | * Initializes file storage. |
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| 252 | */ |
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| 253 | 10 | protected function initStorage() |
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| 272 | |||
| 273 | /** |
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| 274 | * Serialize rate to JSON string. |
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| 275 | * |
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| 276 | * @param RateInterface $rate Rate to serialize. |
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| 277 | * @return string JSON representation of rate. |
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| 278 | */ |
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| 279 | 10 | protected function toJson(RateInterface $rate) |
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| 292 | |||
| 293 | /** |
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| 294 | * Deserialize JSON string to Rate |
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| 295 | * |
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| 296 | * @param string $json Serialized rate. |
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| 297 | * @return Rate Deserialized rate. |
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| 298 | */ |
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| 299 | 10 | protected function fromJson($json) |
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| 314 | |||
| 315 | /** |
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| 316 | * Extract requested page from filter criteria. |
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| 317 | * |
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| 318 | * @param array $rates Rates to filter for pagination. |
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| 319 | * @param array $criteria Filter criteria. |
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| 320 | * @return RateInterface[] Paginated rates. |
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| 321 | */ |
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| 322 | 4 | protected function paginate(array $rates, $criteria) |
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| 338 | } |
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| 339 |