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 DatabasebackupLog 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 DatabasebackupLog, and based on these observations, apply Extract Interface, too.
1 | <?php |
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12 | class DatabasebackupLog extends DataObject |
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13 | { |
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14 | private static $singular_name = "Database Backup"; |
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15 | |||
16 | private static $plural_name = "Database Backups"; |
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17 | |||
18 | private static $db = array( |
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19 | "Title" => "Varchar(255)", |
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20 | "Notes" => "Text", |
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21 | "FullLocation" => "Varchar(255)", |
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22 | "SizeInBytes" => "Int", |
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23 | "DebugMessage" => "Text" |
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24 | ); |
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25 | |||
26 | private static $indexes = array( |
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27 | "FullLocation" => true |
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28 | ); |
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29 | |||
30 | private static $default_sort = "Created DESC"; |
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31 | |||
32 | private static $casting = array( |
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33 | "SizeInMegabytes" => "Int" |
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34 | ); |
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35 | |||
36 | private static $summary_fields = array( |
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37 | "Title" => "Title", |
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38 | "Created" => "Created", |
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39 | "SizeInMegabytes" => "Size (in Mb.)", |
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40 | ); |
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41 | |||
42 | /** |
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43 | * location for backup file e.g. /var/backups/db.sql |
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44 | * @var String |
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45 | */ |
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46 | private static $full_location_for_db_backup_file = ""; |
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47 | |||
48 | /** |
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49 | * number of cycles before the database backups get deleted forgood... |
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50 | * @var Int |
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51 | */ |
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52 | private static $max_db_copies = 3; |
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53 | |||
54 | /** |
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55 | * at the moment only the gzip compression is supported! |
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56 | * @var String |
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57 | */ |
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58 | private static $compression = ""; |
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59 | |||
60 | /** |
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61 | * for security reasons we set this to false ... |
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62 | * @var Boolean |
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63 | */ |
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64 | private static $allow_restores_in_live_environment = false; |
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65 | |||
66 | public function canCreate($member = null) |
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70 | |||
71 | public function canDelete($member = null) |
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75 | |||
76 | public function canEdit($member = null) |
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80 | |||
81 | public function getCMSFields() |
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92 | |||
93 | /** |
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94 | * @casting |
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95 | * @return Int |
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96 | */ |
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97 | public function getSizeInMegabytes() |
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105 | |||
106 | /** |
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107 | * Adds a button the Site Config page of the CMS to rebuild the Lucene search index. |
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108 | */ |
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109 | public function getCMSActions() |
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144 | |||
145 | /** |
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146 | * if backup does not exist then make it ... |
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147 | * set size |
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148 | */ |
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149 | public function onBeforeWrite() |
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179 | |||
180 | /** |
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181 | * delete me if file does not exist |
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182 | */ |
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183 | public function onAfterWrite() |
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191 | |||
192 | |||
193 | /** |
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194 | * delete file if I get deleted |
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195 | */ |
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196 | public function onBeforeDelete() |
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204 | |||
205 | /** |
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206 | * |
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207 | * @return Boolean |
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208 | */ |
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209 | public function restoreDatabaseBackup() |
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232 | |||
233 | /** |
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234 | * we have this so that when we restore a database |
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235 | * we dont loose the backup information... |
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236 | * saves all the logs to session |
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237 | */ |
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238 | protected function saveToSession() |
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250 | |||
251 | /** |
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252 | * |
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253 | * retrieves and updates all the logs from session |
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254 | */ |
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255 | protected function retrieveFromSession() |
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268 | |||
269 | /** |
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270 | * move all of the database copies up one, |
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271 | * deleting the upper one. |
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272 | * |
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273 | * Returns the name of the file name freed up ... (by moving all of them one up...) |
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274 | * |
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275 | * @param string $fileLocation |
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276 | * |
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277 | * @return string File Location |
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278 | * |
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279 | */ |
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280 | protected function cycleDatabaseBackupFiles($fileLocation) |
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348 | |||
349 | /** |
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350 | * returns best file location with compression extension... |
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351 | * |
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352 | * @return String | Null |
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353 | */ |
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354 | protected function getFullLocationWithExtension() |
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366 | |||
367 | /** |
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368 | * returns file name for older back up file (cycled one) |
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369 | * |
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370 | * @param String $fileLocation |
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371 | * @param Int $position |
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372 | * |
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373 | * @return String |
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374 | */ |
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375 | protected function olderBackupFileName($fileLocation, $position) |
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379 | |||
380 | /** |
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381 | * check for existing backups |
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382 | * |
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383 | */ |
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384 | public function requireDefaultRecords() |
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413 | } |
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414 |