Complex classes like JSONStorage 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 JSONStorage, and based on these observations, apply Extract Interface, too.
1 | <?php |
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27 | class JSONStorage extends CComponent |
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28 | { |
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29 | /** |
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30 | * const string the key to keep value information |
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31 | */ |
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32 | const META = 'meta'; |
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33 | |||
34 | /** |
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35 | * const string the key of the registry |
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36 | */ |
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37 | const REGISTRY = 'registry'; |
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38 | |||
39 | /** |
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40 | * @var string the filename to save the values to |
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41 | */ |
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42 | protected $filename = 'registry.json'; |
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43 | |||
44 | /** |
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45 | * @var string the full path to the directory with read/write access to save the registry to. If none set, the |
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46 | * component will used the application's runtime folder |
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47 | */ |
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48 | protected $path; |
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49 | |||
50 | /** |
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51 | * @var bool whether the registry has changed or not |
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52 | */ |
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53 | protected $dirty = false; |
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54 | |||
55 | /** |
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56 | * @var null|string the name of the default registry |
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57 | */ |
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58 | protected $default = "default"; |
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59 | |||
60 | /** |
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61 | * @var array the data of the registry |
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62 | */ |
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63 | protected $data = array( |
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64 | self::META => array( |
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65 | "updated" => "", |
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66 | "hash" => "" |
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67 | ), |
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68 | self::REGISTRY => array( |
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69 | /* collection name */ |
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70 | "default" => array( |
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71 | "foo" => "bar" /* attributes by example */ |
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72 | ) |
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73 | ) |
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74 | ); |
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75 | |||
76 | /** |
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77 | * class constructor |
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78 | * |
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79 | * @param null $registry |
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80 | */ |
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81 | public function __construct($registry = null) |
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98 | |||
99 | /** |
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100 | * class destructor - flush data |
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101 | */ |
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102 | public function __destruct() |
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106 | |||
107 | /** |
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108 | * Fires before registry has been saved |
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109 | * |
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110 | * @param CEvent $event |
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111 | */ |
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112 | public function onBeforeSave($event) |
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116 | |||
117 | /** |
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118 | * Fires after the registry has been saved |
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119 | * |
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120 | * @param CEvent $event |
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121 | */ |
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122 | public function onAfterSave($event) |
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126 | |||
127 | /** |
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128 | * Property set path |
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129 | * |
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130 | * @param string $path the full path of the directory with read/write access to save the registry file to |
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131 | * |
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132 | * @return bool |
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133 | * @throws Exception |
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134 | */ |
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135 | public function setPath($path) |
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143 | |||
144 | /** |
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145 | * Property get path |
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146 | * @return string |
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147 | */ |
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148 | public function getPath() |
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152 | |||
153 | /** |
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154 | * Property set file |
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155 | * |
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156 | * @param string $file the filename to save the registry to |
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157 | */ |
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158 | public function setFile($file) |
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162 | |||
163 | /** |
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164 | * Property get file |
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165 | * @return string filename |
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166 | */ |
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167 | public function getFile() |
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171 | |||
172 | /** |
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173 | * Verifies data integrity |
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174 | * @return bool |
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175 | */ |
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176 | public function verify() |
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185 | |||
186 | /** |
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187 | * Loads registry data into memory |
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188 | * @throws Exception |
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189 | */ |
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190 | public function load() |
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191 | { |
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192 | $filename = $this->getFile(); |
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193 | if (!file_exists($filename)) |
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194 | return; |
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195 | |||
196 | $json = file_get_contents($filename); |
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197 | if (strlen($json) == 0) |
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198 | return; |
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199 | |||
200 | $data = $this->decode($json); |
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201 | if ($data === null) |
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202 | throw new Exception('Error while trying to decode ' . $filename . '.'); |
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203 | |||
204 | $this->data = $data; |
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205 | |||
206 | if (!$this->verify()) |
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207 | throw new Exception($filename . ' failed checksum validation.'); |
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208 | } |
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209 | |||
210 | /** |
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211 | * Saves registry data to the file |
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212 | */ |
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213 | public function save() |
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223 | |||
224 | /** |
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225 | * Saves data to the registry |
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226 | * |
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227 | * @param string $key the name of the key that will hold the data |
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228 | * @param array $data the data to save |
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229 | * @param string $registry the name of the registry |
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230 | * |
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231 | * @return bool |
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232 | */ |
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233 | public function setData($key, $data, $registry = null) |
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245 | |||
246 | /** |
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247 | * Retrieves a data value from the registry |
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248 | * |
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249 | * @param string $key the name of the key that holds the data |
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250 | * @param string $registry the registry name |
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251 | * |
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252 | * @return mixed the data in the key value, null otherwise |
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253 | */ |
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254 | public function getData($key, $registry = null) |
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266 | |||
267 | /** |
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268 | * Removes data from a key in the registry |
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269 | * |
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270 | * @param string $key the key name that holds the data to remove |
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271 | * @param string $registry the registry name |
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272 | * |
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273 | * @return bool true if successful, false otherwise |
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274 | */ |
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275 | public function removeData($key, $registry = null) |
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290 | |||
291 | /** |
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292 | * Retrieves the number of keys in registry |
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293 | * |
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294 | * @param string $registry the registry name |
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295 | * |
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296 | * @return int the data length |
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297 | */ |
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298 | public function getLength($registry = null) |
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308 | |||
309 | /** |
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310 | * Retrieves a registry collection based on its name |
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311 | * |
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312 | * @param string $registry the name of the registry to retrieve |
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313 | * |
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314 | * @return mixed|null the registry, null if none found |
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315 | */ |
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316 | public function getRegistry($registry) |
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320 | |||
321 | /** |
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322 | * Checkes whether a collection exists (registry) |
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323 | * |
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324 | * @param string $registry the name of the registry to check existence |
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325 | * |
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326 | * @return bool |
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327 | */ |
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328 | public function registryExists($registry) |
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332 | |||
333 | /** |
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334 | * Add new collection name |
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335 | * |
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336 | * @param string $registry the name of the registry (collection) to create |
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337 | * |
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338 | * @return bool |
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339 | */ |
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340 | public function addRegistry($registry) |
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349 | |||
350 | /** |
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351 | * Remove an existing collection and all associated data |
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352 | * |
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353 | * @param string $registry the name of the registry to remove |
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354 | * |
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355 | * @return bool |
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356 | */ |
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357 | public function removeRegistry($registry) |
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366 | |||
367 | /** |
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368 | * Saves the global registry to the file |
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369 | * @return bool |
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370 | * @throws Exception |
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371 | */ |
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372 | private function flush() |
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373 | { |
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374 | // check if writeback is needed |
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375 | if ($this->dirty == false) |
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376 | return true; |
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377 | |||
378 | // prepare to writeback to file |
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379 | $data = $this->data; |
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380 | $registry = $this->encode($this->data[self::REGISTRY]); |
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381 | $data[self::META]["updated"] = date("c"); |
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382 | $data[self::META]["hash"] = md5($registry); |
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383 | |||
384 | // overwrite existing data |
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385 | $written = file_put_contents($this->getFile(), $this->encode($data)); |
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386 | if ($written === false) |
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387 | throw new Exception(strtr( 'Unable to write back to {FILE}. Data will be lost!', array('{FILE}' => $this->getFile()) )); |
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388 | |||
389 | return true; |
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390 | } |
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391 | |||
392 | /** |
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393 | * JSON encodes the data |
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394 | * |
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395 | * @param mixed $data |
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396 | * |
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397 | * @return string |
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398 | */ |
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399 | private function encode($data) |
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403 | |||
404 | /** |
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405 | * JSON decodes the data |
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406 | * |
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407 | * @param string $data |
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408 | * |
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409 | * @return mixed |
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410 | */ |
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411 | private function decode($data) |
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415 | } |
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416 |
When comparing two booleans, it is generally considered safer to use the strict comparison operator.