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 MongoGridFS 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 MongoGridFS, and based on these observations, apply Extract Interface, too.
1 | <?php |
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20 | class MongoGridFS extends MongoCollection |
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21 | { |
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22 | const ASCENDING = 1; |
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23 | const DESCENDING = -1; |
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24 | |||
25 | /** |
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26 | * @link http://php.net/manual/en/class.mongogridfs.php#mongogridfs.props.chunks |
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27 | * @var $chunks MongoCollection |
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28 | */ |
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29 | public $chunks; |
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30 | |||
31 | /** |
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32 | * @link http://php.net/manual/en/class.mongogridfs.php#mongogridfs.props.filesname |
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33 | * @var $filesName string |
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34 | */ |
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35 | protected $filesName; |
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36 | |||
37 | /** |
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38 | * @link http://php.net/manual/en/class.mongogridfs.php#mongogridfs.props.chunksname |
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39 | * @var $chunksName string |
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40 | */ |
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41 | protected $chunksName; |
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42 | |||
43 | /** |
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44 | * @var MongoDB |
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45 | */ |
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46 | private $database; |
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47 | |||
48 | private $prefix; |
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49 | |||
50 | private $defaultChunkSize = 261120; |
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51 | |||
52 | /** |
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53 | * Files as stored across two collections, the first containing file meta |
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54 | * information, the second containing chunks of the actual file. By default, |
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55 | * fs.files and fs.chunks are the collection names used. |
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56 | * |
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57 | * @link http://php.net/manual/en/mongogridfs.construct.php |
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58 | * @param MongoDB $db Database |
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59 | * @param string $prefix [optional] <p>Optional collection name prefix.</p> |
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60 | * @param mixed $chunks [optional] |
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61 | * @throws \Exception |
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62 | */ |
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63 | public function __construct(MongoDB $db, $prefix = "fs", $chunks = null) |
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81 | |||
82 | /** |
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83 | * Delete a file from the database |
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84 | * |
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85 | * @link http://php.net/manual/en/mongogridfs.delete.php |
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86 | * @param mixed $id _id of the file to remove |
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87 | * @return boolean Returns true if the remove was successfully sent to the database. |
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88 | */ |
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89 | public function delete($id) |
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96 | |||
97 | /** |
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98 | * Drops the files and chunks collections |
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99 | * @link http://php.net/manual/en/mongogridfs.drop.php |
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100 | * @return array The database response |
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101 | */ |
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102 | public function drop() |
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107 | |||
108 | /** |
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109 | * @link http://php.net/manual/en/mongogridfs.find.php |
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110 | * @param array $query The query |
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111 | * @param array $fields Fields to return |
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112 | * @param array $options Options for the find command |
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113 | * @return MongoGridFSCursor A MongoGridFSCursor |
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114 | */ |
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115 | View Code Duplication | public function find(array $query = [], array $fields = []) |
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122 | |||
123 | /** |
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124 | * Returns a single file matching the criteria |
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125 | * |
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126 | * @link http://www.php.net/manual/en/mongogridfs.findone.php |
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127 | * @param mixed $query The fields for which to search or a filename to search for. |
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128 | * @param array $fields Fields of the results to return. |
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129 | * @param array $options Options for the find command |
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130 | * @return MongoGridFSFile|null |
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131 | */ |
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132 | public function findOne($query = [], array $fields = [], array $options = []) |
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141 | |||
142 | /** |
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143 | * Retrieve a file from the database |
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144 | * |
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145 | * @link http://www.php.net/manual/en/mongogridfs.get.php |
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146 | * @param mixed $id _id of the file to find. |
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147 | * @return MongoGridFSFile|null |
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148 | */ |
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149 | public function get($id) |
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153 | |||
154 | /** |
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155 | * Stores a file in the database |
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156 | * |
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157 | * @link http://php.net/manual/en/mongogridfs.put.php |
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158 | * @param string $filename The name of the file |
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159 | * @param array $extra Other metadata to add to the file saved |
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160 | * @param array $options An array of options for the insert operations executed against the chunks and files collections. |
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161 | * @return mixed Returns the _id of the saved object |
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162 | */ |
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163 | public function put($filename, array $extra = [], array $options = []) |
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167 | |||
168 | /** |
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169 | * Removes files from the collections |
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170 | * |
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171 | * @link http://www.php.net/manual/en/mongogridfs.remove.php |
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172 | * @param array $criteria Description of records to remove. |
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173 | * @param array $options Options for remove. |
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174 | * @throws MongoCursorException |
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175 | * @return boolean |
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176 | */ |
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177 | public function remove(array $criteria = [], array $options = []) |
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189 | |||
190 | /** |
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191 | * Chunkifies and stores bytes in the database |
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192 | * @link http://php.net/manual/en/mongogridfs.storebytes.php |
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193 | * @param string $bytes A string of bytes to store |
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194 | * @param array $extra Other metadata to add to the file saved |
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195 | * @param array $options Options for the store. "safe": Check that this store succeeded |
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196 | * @return mixed The _id of the object saved |
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197 | */ |
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198 | public function storeBytes($bytes, array $extra = [], array $options = []) |
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222 | |||
223 | /** |
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224 | * Stores a file in the database |
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225 | * |
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226 | * @link http://php.net/manual/en/mongogridfs.storefile.php |
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227 | * @param string $filename The name of the file |
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228 | * @param array $extra Other metadata to add to the file saved |
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229 | * @param array $options Options for the store. "safe": Check that this store succeeded |
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230 | * @return mixed Returns the _id of the saved object |
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231 | * @throws MongoGridFSException |
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232 | * @throws Exception |
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233 | */ |
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234 | public function storeFile($filename, array $extra = [], array $options = []) |
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298 | |||
299 | /** |
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300 | * Saves an uploaded file directly from a POST to the database |
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301 | * |
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302 | * @link http://www.php.net/manual/en/mongogridfs.storeupload.php |
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303 | * @param string $name The name attribute of the uploaded file, from <input type="file" name="something"/>. |
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304 | * @param array $metadata An array of extra fields for the uploaded file. |
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305 | * @return mixed Returns the _id of the uploaded file. |
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306 | * @throws MongoGridFSException |
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307 | */ |
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308 | public function storeUpload($name, array $metadata = []) |
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333 | |||
334 | /** |
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335 | * Creates the index on the chunks collection |
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336 | */ |
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337 | private function createChunksIndex() |
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344 | |||
345 | /** |
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346 | * Inserts a single chunk into the database |
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347 | * |
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348 | * @param mixed $fileId |
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349 | * @param string $data |
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350 | * @param int $chunkNumber |
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351 | * @return array|bool |
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352 | */ |
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353 | private function insertChunk($fileId, $data, $chunkNumber) |
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369 | |||
370 | /** |
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371 | * Splits a string into chunks and writes them to the database |
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372 | * |
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373 | * @param string $bytes |
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374 | * @param array $record |
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375 | */ |
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376 | private function insertChunksFromBytes($bytes, $record) |
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387 | |||
388 | /** |
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389 | * Reads chunks from a file and writes them to the database |
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390 | * |
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391 | * @param resource $handle |
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392 | * @param array $record |
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393 | * @param string $md5 |
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394 | * @return int Returns the number of bytes written to the database |
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395 | */ |
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396 | private function insertChunksFromFile($handle, $record, &$md5) |
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420 | |||
421 | /** |
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422 | * Writes a file record to the database |
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423 | * |
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424 | * @param $record |
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425 | * @param array $options |
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426 | * @return array |
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427 | */ |
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428 | private function insertFile($record, array $options = []) |
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444 | |||
445 | private function isOKResult($result) |
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450 | |||
451 | /** |
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452 | * @return array |
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453 | */ |
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454 | public function __sleep() |
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458 | } |
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459 |
This check looks for a call to a parent method whose name is different than the method from which it is called.
Consider the following code:
The
getFirstName()
method in theSon
calls the wrong method in the parent class.