| Total Complexity | 53 |
| Total Lines | 489 |
| Duplicated Lines | 0 % |
| Changes | 2 | ||
| Bugs | 1 | Features | 1 |
Complex classes like JibitFileCache 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.
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 JibitFileCache, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 10 | class JibitFileCache |
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| 11 | { |
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| 12 | /** |
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| 13 | * Path to the cache directory |
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| 14 | * @var string |
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| 15 | */ |
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| 16 | private $cacheDir; |
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| 17 | |||
| 18 | /** |
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| 19 | * Cache file name |
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| 20 | * @var string |
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| 21 | */ |
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| 22 | private $cacheFilename; |
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| 23 | |||
| 24 | /** |
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| 25 | * Cache file name, hashed with sha1. Used as an actual file name |
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| 26 | * @var string |
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| 27 | */ |
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| 28 | private $cacheFilenameHashed; |
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| 29 | |||
| 30 | /** |
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| 31 | * Cache file extension |
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| 32 | * @var string |
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| 33 | */ |
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| 34 | private $cacheFileExtension; |
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| 35 | |||
| 36 | /** |
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| 37 | * Holds current cache |
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| 38 | * @var array |
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| 39 | */ |
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| 40 | private $cacheArray; |
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| 41 | |||
| 42 | /** |
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| 43 | * If true, cache expire after one second |
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| 44 | * @var bool |
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| 45 | */ |
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| 46 | private $devMode; |
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| 47 | |||
| 48 | /** |
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| 49 | * Cache constructor. |
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| 50 | * @param string $cacheDirPath cache directory. Must end with "/" |
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| 51 | * @param string $cacheFileName cache file name |
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| 52 | * @param string $cacheFileExtension cache file extension. Must end with .php |
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| 53 | * @throws \Exception if there is a problem loading the cache |
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| 54 | */ |
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| 55 | public function __construct($cacheDirPath = "cache/", $cacheFileName = "defaultcache", $cacheFileExtension = ".cache.php") |
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| 56 | { |
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| 57 | $this->setCacheFilename($cacheFileName); |
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| 58 | $this->setCacheDir($cacheDirPath); |
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| 59 | $this->setCacheFileExtension($cacheFileExtension); |
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| 60 | $this->setDevMode(false); |
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| 61 | |||
| 62 | $this->reloadFromDisc(); |
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| 63 | } |
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| 64 | |||
| 65 | /** |
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| 66 | * Loads cache |
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| 67 | * @return array array filled with data |
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| 68 | * @throws \Exception if there is a problem loading the cache |
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| 69 | */ |
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| 70 | private function loadCacheFile() |
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| 71 | { |
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| 72 | $filepath = $this->getCacheFilePath(); |
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| 73 | $file = @file_get_contents($filepath); |
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| 74 | |||
| 75 | if (!$file) { |
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| 76 | unlink($filepath); |
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| 77 | throw new \Exception("Cannot load cache file! ({$this->getCacheFilename()})"); |
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| 78 | } |
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| 79 | |||
| 80 | // Remove the first line which prevents direct access to the file |
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| 81 | $file = $this->stripFirstLine($file); |
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| 82 | $data = unserialize($file); |
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| 83 | |||
| 84 | if ($data === false) { |
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| 85 | unlink($filepath); |
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| 86 | throw new \Exception("Cannot unserialize cache file, cache file deleted. ({$this->getCacheFilename()})"); |
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| 87 | } |
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| 88 | |||
| 89 | if (!isset($data["hash-sum"])) { |
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| 90 | unlink($filepath); |
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| 91 | throw new \Exception("No hash found in cache file, cache file deleted"); |
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| 92 | } |
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| 93 | |||
| 94 | $hash = $data["hash-sum"]; |
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| 95 | unset($data["hash-sum"]); |
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| 96 | |||
| 97 | if ($hash !== $this->getStringHash(serialize($data))) { |
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| 98 | unlink($filepath); |
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| 99 | throw new \Exception("Cache data miss-hashed, cache file deleted"); |
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| 100 | } |
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| 101 | |||
| 102 | return $data; |
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| 103 | } |
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| 104 | |||
| 105 | /** |
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| 106 | * Saves current cacheArray into the cache file |
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| 107 | * @return $this |
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| 108 | * @throws \Exception if the file cannot be saved |
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| 109 | */ |
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| 110 | private function saveCacheFile() |
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| 111 | { |
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| 112 | if (!file_exists($this->getCacheDir())) { |
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| 113 | @mkdir($this->getCacheDir()); |
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| 114 | } |
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| 115 | |||
| 116 | $cache = $this->cacheArray; |
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| 117 | $cache["hash-sum"] = $this->getStringHash(serialize($cache)); |
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| 118 | $data = serialize($cache); |
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| 119 | $firstLine = '<?php die("Access denied") ?>' . PHP_EOL; |
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| 120 | $success = file_put_contents($this->getCacheFilePath(), $firstLine . $data) !== false; |
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| 121 | |||
| 122 | if (!$success) { |
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| 123 | throw new \Exception("Cannot save cache"); |
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| 124 | } |
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| 125 | |||
| 126 | return $this; |
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| 127 | } |
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| 128 | |||
| 129 | /** |
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| 130 | * Stores $data under $key for $expiration seconds |
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| 131 | * If $key is already used, then current data will be overwritten |
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| 132 | * @param $key string key associated with the current data |
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| 133 | * @param $data mixed data to store |
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| 134 | * @param $expiration int number of seconds before the $key expires |
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| 135 | * @param $permanent bool if true, this item will not be automatically cleared after expiring |
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| 136 | * @return $this |
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| 137 | * @throws \Exception if the file cannot be saved |
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| 138 | */ |
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| 139 | public function store($key, $data, $expiration = 60, $permanent = false) |
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| 140 | { |
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| 141 | if (!is_string($key)) { |
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| 142 | throw new \InvalidArgumentException('$key must be a string, got type "' . get_class($key) . '" instead'); |
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| 143 | } |
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| 144 | |||
| 145 | if ($this->isDevMode()) { |
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| 146 | $expiration = 1; |
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| 147 | } |
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| 148 | |||
| 149 | $storeData = [ |
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| 150 | "time" => time(), |
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| 151 | "expire" => $expiration, |
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| 152 | "data" => $data, |
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| 153 | "permanent" => $permanent |
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| 154 | ]; |
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| 155 | |||
| 156 | $this->cacheArray[$key] = $storeData; |
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| 157 | $this->saveCacheFile(); |
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| 158 | return $this; |
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| 159 | } |
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| 160 | |||
| 161 | /** |
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| 162 | * Returns data associated with $key |
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| 163 | * @param $key string |
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| 164 | * @param bool $meta if true, array will be returned containing metadata alongside data itself |
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| 165 | * @return mixed|null returns data if $key is valid and not expired, NULL otherwise |
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| 166 | * @throws \Exception if the file cannot be saved |
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| 167 | */ |
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| 168 | public function retrieve($key, $meta = false) |
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| 169 | { |
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| 170 | $this->eraseExpired(); |
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| 171 | |||
| 172 | if (!isset($this->cacheArray[$key])) { |
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| 173 | return null; |
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| 174 | } |
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| 175 | |||
| 176 | $data = $this->cacheArray[$key]; |
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| 177 | return $meta ? $data : @$data["data"]; |
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| 178 | } |
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| 179 | |||
| 180 | /** |
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| 181 | * Calls $refreshCallback if $key does not exists or is expired. |
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| 182 | * Also returns latest data associated with $key. |
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| 183 | * This is basically a shortcut, turns this: |
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| 184 | * <code> |
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| 185 | * if($cache->isExpired(key)) { |
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| 186 | * $cache->store(key, $newdata, 10); |
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| 187 | * } |
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| 188 | * |
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| 189 | * $data = $cache->retrieve(key); |
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| 190 | * </code> |
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| 191 | * |
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| 192 | * to this: |
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| 193 | * |
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| 194 | * <code> |
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| 195 | * $data = $cache->refreshIfExpired(key, function () { |
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| 196 | * return $newdata; |
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| 197 | * }, 10); |
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| 198 | * </code> |
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| 199 | * |
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| 200 | * @param $key |
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| 201 | * @param $refreshCallback Callback called when data needs to be refreshed. Should return data to be cached. |
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| 202 | * @param int $cacheTime Cache time. Defaults to 60 |
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| 203 | * @param bool $meta If true, returns data with meta. @see retrieve |
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| 204 | * @return mixed|null Data currently stored under key |
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| 205 | * @throws \Exception if the file cannot be saved |
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| 206 | */ |
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| 207 | public function refreshIfExpired($key, $refreshCallback, $cacheTime = 60, $meta = false) |
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| 208 | { |
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| 209 | if ($this->isExpired($key)) { |
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| 210 | $this->store($key, $refreshCallback(), $cacheTime); |
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| 211 | } |
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| 212 | |||
| 213 | return $this->retrieve($key, $meta); |
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| 214 | } |
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| 215 | |||
| 216 | /** |
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| 217 | * Erases data associated with $key |
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| 218 | * @param $key string |
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| 219 | * @return bool true if $key was found and removed, false otherwise |
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| 220 | * @throws \Exception if the file cannot be saved |
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| 221 | */ |
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| 222 | public function eraseKey($key) |
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| 223 | { |
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| 224 | if (!$this->isCached($key, false)) { |
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| 225 | return false; |
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| 226 | } |
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| 227 | |||
| 228 | unset($this->cacheArray[$key]); |
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| 229 | $this->saveCacheFile(); |
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| 230 | return true; |
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| 231 | } |
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| 232 | |||
| 233 | /** |
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| 234 | * Erases expired keys from cache |
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| 235 | * @return int number of erased entries |
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| 236 | * @throws \Exception if the file cannot be saved |
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| 237 | */ |
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| 238 | public function eraseExpired() |
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| 239 | { |
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| 240 | $counter = 0; |
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| 241 | |||
| 242 | foreach ($this->cacheArray as $key => $value) { |
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| 243 | if (!$value["permanent"] && $this->isExpired($key, false)) { |
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| 244 | $this->eraseKey($key); |
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| 245 | $counter++; |
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| 246 | } |
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| 247 | } |
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| 248 | |||
| 249 | if ($counter > 0) { |
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| 250 | $this->saveCacheFile(); |
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| 251 | } |
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| 252 | |||
| 253 | return $counter; |
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| 254 | } |
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| 255 | |||
| 256 | /** |
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| 257 | * Clears the cache |
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| 258 | * @throws \Exception if the file cannot be saved |
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| 259 | */ |
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| 260 | public function clearCache() |
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| 261 | { |
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| 262 | $this->cacheArray = []; |
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| 263 | $this->saveCacheFile(); |
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| 264 | } |
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| 265 | |||
| 266 | /** |
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| 267 | * Checks if $key has expired |
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| 268 | * @param $key |
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| 269 | * @param bool $eraseExpired if true, expired data will |
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| 270 | * be cleared before running this function |
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| 271 | * @return bool |
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| 272 | * @throws \Exception if the file cannot be saved |
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| 273 | */ |
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| 274 | public function isExpired($key, $eraseExpired = true) |
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| 275 | { |
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| 276 | if ($eraseExpired) { |
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| 277 | $this->eraseExpired(); |
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| 278 | } |
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| 279 | |||
| 280 | if (!$this->isCached($key, false)) { |
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| 281 | return true; |
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| 282 | } |
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| 283 | |||
| 284 | $item = $this->cacheArray[$key]; |
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| 285 | |||
| 286 | return $this->isTimestampExpired($item["time"], $item["expire"]); |
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| 287 | } |
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| 288 | |||
| 289 | /** |
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| 290 | * Checks if $key is cached |
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| 291 | * @param $key |
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| 292 | * @param bool $eraseExpired if true, expired data will |
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| 293 | * be cleared before running this function |
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| 294 | * @return bool |
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| 295 | * @throws \Exception if the file cannot be saved |
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| 296 | */ |
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| 297 | public function isCached($key, $eraseExpired = true) |
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| 304 | } |
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| 305 | |||
| 306 | /** |
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| 307 | * Checks if the timestamp expired |
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| 308 | * @param $timestamp int |
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| 309 | * @param $expiration int number of seconds after the timestamp expires |
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| 310 | * @return bool true if the timestamp expired, false otherwise |
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| 311 | */ |
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| 312 | private function isTimestampExpired($timestamp, $expiration) |
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| 313 | { |
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| 314 | $timeDiff = time() - $timestamp; |
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| 315 | return $timeDiff >= $expiration; |
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| 316 | } |
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| 317 | |||
| 318 | /** |
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| 319 | * Prints cache file using var_dump, useful for debugging |
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| 320 | */ |
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| 321 | public function debugCache() |
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| 322 | { |
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| 323 | if (file_exists($this->getCacheFilePath())) { |
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| 324 | var_dump(unserialize($this->stripFirstLine(file_get_contents($this->getCacheFilePath())))); |
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| 325 | } |
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| 326 | } |
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| 327 | |||
| 328 | /** |
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| 329 | * Reloads cache from disc. Can be used after changing file name, extension or cache dir |
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| 330 | * using functions instead of constructor. (This class loads data once, when is created) |
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| 331 | * @throws \Exception if there is a problem loading the cache |
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| 332 | */ |
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| 333 | public function reloadFromDisc() |
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| 334 | { |
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| 335 | // Try to load the cache, otherwise create a empty array |
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| 336 | $this->cacheArray = is_readable($this->getCacheFilePath()) ? $this->loadCacheFile() : []; |
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| 337 | } |
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| 338 | |||
| 339 | /** |
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| 340 | * Returns md5 hash of the given string. |
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| 341 | * @param $str string String to be hashed |
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| 342 | * @return string MD5 hash |
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| 343 | * @throws \InvalidArgumentException if $str is not a string |
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| 344 | */ |
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| 345 | private function getStringHash($str) |
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| 346 | { |
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| 347 | if (!is_string($str)) { |
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| 348 | throw new \InvalidArgumentException('$key must be a string, got type "' . get_class($str) . '" instead'); |
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| 349 | } |
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| 350 | |||
| 351 | return md5($str); |
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| 352 | } |
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| 353 | |||
| 354 | // Utils |
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| 355 | |||
| 356 | /** |
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| 357 | * Strips the first line from string |
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| 358 | * https://stackoverflow.com/a/7740485 |
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| 359 | * @param $str |
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| 360 | * @return bool|string stripped text without the first line or false on failure |
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| 361 | */ |
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| 362 | private function stripFirstLine($str) |
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| 363 | { |
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| 364 | $position = strpos($str, "\n"); |
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| 365 | |||
| 366 | if ($position === false) { |
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| 367 | return $str; |
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| 368 | } |
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| 369 | |||
| 370 | return substr($str, $position + 1); |
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| 371 | } |
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| 372 | |||
| 373 | // Generic setters and getters below |
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| 374 | |||
| 375 | /** |
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| 376 | * Returns cache directory |
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| 377 | * @return string |
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| 378 | */ |
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| 379 | public function getCacheDir() |
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| 380 | { |
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| 381 | return $this->cacheDir; |
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| 382 | } |
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| 383 | |||
| 384 | /** |
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| 385 | * Sets new cache directory. If you want to read data from new file, consider calling reloadFromDisc. |
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| 386 | * @param string $cacheDir new cache directory. Must end with "/" |
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| 387 | * @return $this |
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| 388 | */ |
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| 389 | public function setCacheDir($cacheDir) |
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| 390 | { |
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| 391 | // Add "/" to the end if its not here |
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| 392 | if (substr($cacheDir, -1) !== "/") { |
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| 393 | $cacheDir .= "/"; |
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| 394 | } |
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| 395 | |||
| 396 | $this->cacheDir = $cacheDir; |
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| 397 | return $this; |
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| 398 | } |
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| 399 | |||
| 400 | /** |
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| 401 | * Returns cache file name, hashed with sha1. Used as an actual file name |
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| 402 | * The new value is computed when using setCacheFilename method. |
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| 403 | * @return string |
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| 404 | */ |
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| 405 | public function getCacheFilenameHashed() |
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| 406 | { |
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| 407 | return $this->cacheFilenameHashed; |
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| 408 | } |
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| 409 | |||
| 410 | /** |
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| 411 | * Returns cache file name |
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| 412 | * @return string |
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| 413 | */ |
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| 414 | public function getCacheFilename() |
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| 415 | { |
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| 416 | return $this->cacheFilename; |
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| 417 | } |
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| 418 | |||
| 419 | /** |
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| 420 | * Sets new cache file name. If you want to read data from new file, consider calling reloadFromDisc. |
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| 421 | * @param string $cacheFilename |
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| 422 | * @return $this |
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| 423 | * @throws \InvalidArgumentException if $cacheFilename is not a string |
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| 424 | */ |
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| 425 | public function setCacheFilename($cacheFilename) |
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| 434 | } |
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| 435 | |||
| 436 | /** |
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| 437 | * Returns cache file extension |
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| 438 | * @return string |
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| 439 | */ |
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| 440 | public function getCacheFileExtension() |
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| 441 | { |
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| 442 | return $this->cacheFileExtension; |
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| 443 | } |
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| 444 | |||
| 445 | /** |
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| 446 | * Sets new cache file extension. If you want to read data from new file, consider calling reloadFromDisc. |
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| 447 | * @param string $cacheFileExtension new cache file extension. Must end with ".php" |
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| 448 | * @return $this |
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| 449 | */ |
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| 450 | public function setCacheFileExtension($cacheFileExtension) |
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| 451 | { |
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| 452 | // Add ".php" to the end if its not here |
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| 453 | if (substr($cacheFileExtension, -4) !== ".php") { |
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| 454 | $cacheFileExtension .= ".php"; |
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| 455 | } |
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| 456 | |||
| 457 | $this->cacheFileExtension = $cacheFileExtension; |
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| 458 | return $this; |
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| 459 | } |
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| 460 | |||
| 461 | /** |
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| 462 | * Combines directory, filename and extension into a path |
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| 463 | * @return string |
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| 464 | */ |
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| 465 | public function getCacheFilePath() |
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| 466 | { |
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| 467 | return $this->getCacheDir() . $this->getCacheFilenameHashed() . $this->getCacheFileExtension(); |
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| 468 | } |
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| 469 | |||
| 470 | /** |
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| 471 | * Returns raw cache array |
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| 472 | * @return array |
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| 473 | */ |
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| 474 | public function getCacheArray() |
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| 477 | } |
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| 478 | |||
| 479 | /** |
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| 480 | * Returns true if dev mode is on |
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| 481 | * If dev mode is on, cache expire after one second |
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| 482 | * @return bool |
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| 483 | */ |
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| 484 | public function isDevMode() |
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| 485 | { |
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| 486 | return $this->devMode; |
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| 487 | } |
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| 488 | |||
| 489 | /** |
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| 490 | * Sets dev mode on or off |
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| 491 | * If dev mode is on, cache expire after one second |
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| 492 | * @param $devMode |
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| 493 | * @return $this |
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| 494 | */ |
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| 495 | public function setDevMode($devMode) |
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| 499 | } |
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| 500 | } |
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| 501 |
If you suppress an error, we recommend checking for the error condition explicitly: