cache: Refactor cache factory to non-static class

The cache factory can be based on the abstract factory class if it
wasn't static. This allows for higher abstraction and makes future
extensions possible. Also, not all parts of RSS-Bridge need to work
on the same instance of the factory.

References #1001

actions/DisplayAction.php

@@ -82,7 +82,9 @@ class DisplayAction extends ActionAbstract {
 		);
 
 		// Initialize cache
-		$cache = Cache::create(Configuration::getConfig('cache', 'type'));
+		$cacheFac = new CacheFactory();
+		$cacheFac->setWorkingDir(PATH_LIB_CACHES);
+		$cache = $cacheFac->create(Configuration::getConfig('cache', 'type'));
 		$cache->setScope('');
 		$cache->purgeCache(86400); // 24 hours
 		$cache->setKey($cache_params);

bridges/ElloBridge.php

@@ -120,7 +120,9 @@ class ElloBridge extends BridgeAbstract {
 	}
 
 	private function getAPIKey() {
-		$cache = Cache::create(Configuration::getConfig('cache', 'type'));
+		$cacheFac = new CacheFactory();
+		$cacheFac->setWorkingDir(PATH_LIB_CACHES);
+		$cache = $cacheFac->create(Configuration::getConfig('cache', 'type'));
 		$cache->setScope(get_called_class());
 		$cache->setKey(['key']);
 		$key = $cache->loadData();

lib/CacheFactory.php

@@ -31,29 +31,7 @@
  * $cache = Cache::create('FileCache');
  * ```
  */
-class Cache {
-
-	/**
-	 * Holds a path to the working directory.
-	 *
-	 * Do not access this property directly!
-	 * Use {@see Cache::setWorkingDir()} and {@see Cache::getWorkingDir()} instead.
-	 *
-	 * @var string|null
-	 */
-	protected static $workingDir = null;
-
-	/**
-	 * Throws an exception when trying to create a new instance of this class.
-	 * Use {@see Cache::create()} to create a new cache object from the working
-	 * directory.
-	 *
-	 * @throws \LogicException if called.
-	 */
-	public function __construct(){
-		throw new \LogicException('Use ' . __CLASS__ . '::create($name) to create cache objects!');
-	}
-
+class CacheFactory extends FactoryAbstract {
 	/**
 	 * Creates a new cache object from the working directory.
 	 *
@@ -63,14 +41,14 @@ class Cache {
 	 * @param string $name Name of the cache object.
 	 * @return object|bool The cache object or false if the class is not instantiable.
 	 */
-	public static function create($name){
-		$name = self::sanitizeCacheName($name) . 'Cache';
+	public function create($name){
+		$name = $this->sanitizeCacheName($name) . 'Cache';
 
-		if(!self::isCacheName($name)) {
+		if(!$this->isCacheName($name)) {
 			throw new \InvalidArgumentException('Cache name invalid!');
 		}
 
-		$filePath = self::getWorkingDir() . $name . '.php';
+		$filePath = $this->getWorkingDir() . $name . '.php';
 
 		if(!file_exists($filePath)) {
 			throw new \Exception('Cache file ' . $filePath . ' does not exist!');
@@ -85,48 +63,6 @@ class Cache {
 		return false;
 	}
 
-	/**
-	 * Sets the working directory.
-	 *
-	 * @param string $dir Path to a directory containing cache classes
-	 * @throws \InvalidArgumentException if $dir is not a string.
-	 * @throws \Exception if the working directory doesn't exist.
-	 * @throws \InvalidArgumentException if $dir is not a directory.
-	 * @return void
-	 */
-	public static function setWorkingDir($dir){
-		self::$workingDir = null;
-
-		if(!is_string($dir)) {
-			throw new \InvalidArgumentException('Working directory is not a valid string!');
-		}
-
-		if(!file_exists($dir)) {
-			throw new \Exception('Working directory does not exist!');
-		}
-
-		if(!is_dir($dir)) {
-			throw new \InvalidArgumentException('Working directory is not a directory!');
-		}
-
-		self::$workingDir = realpath($dir) . '/';
-	}
-
-	/**
-	 * Returns the working directory.
-	 * The working directory must be set with {@see Cache::setWorkingDir()}!
-	 *
-	 * @throws \LogicException if the working directory is not set.
-	 * @return string The current working directory.
-	 */
-	public static function getWorkingDir(){
-		if(is_null(self::$workingDir)) {
-			throw new \LogicException('Working directory is not set!');
-		}
-
-		return self::$workingDir;
-	}
-
 	/**
 	 * Returns true if the provided name is a valid cache name.
 	 *
@@ -136,7 +72,7 @@ class Cache {
 	 * @param string $name The cache name.
 	 * @return bool true if the name is a valid cache name, false otherwise.
 	 */
-	public static function isCacheName($name){
+	public function isCacheName($name){
 		return is_string($name) && preg_match('/^[A-Z][a-zA-Z0-9-]*$/', $name) === 1;
 	}
 
@@ -147,12 +83,12 @@ class Cache {
 	 *
 	 * @return array List of cache names
 	 */
-	public static function getCacheNames(){
+	public function getCacheNames(){
 
 		static $cacheNames = array(); // Initialized on first call
 
 		if(empty($cacheNames)) {
-			$files = scandir(self::getWorkingDir());
+			$files = scandir($this->getWorkingDir());
 
 			if($files !== false) {
 				foreach($files as $file) {
@@ -183,7 +119,7 @@ class Cache {
 	 * @return string|null The sanitized cache name if the provided name is
 	 * valid, null otherwise.
 	 */
-	protected static function sanitizeCacheName($name) {
+	protected function sanitizeCacheName($name) {
 
 		if(is_string($name)) {
 
@@ -198,9 +134,9 @@ class Cache {
 			}
 
 			// The name is valid if a corresponding file is found on disk
-			if(in_array(strtolower($name), array_map('strtolower', self::getCacheNames()))) {
-				$index = array_search(strtolower($name), array_map('strtolower', self::getCacheNames()));
-				return self::getCacheNames()[$index];
+			if(in_array(strtolower($name), array_map('strtolower', $this->getCacheNames()))) {
+				$index = array_search(strtolower($name), array_map('strtolower', $this->getCacheNames()));
+				return $this->getCacheNames()[$index];
 			}
 
 			Debug::log('Invalid cache name specified: "' . $name . '"!');

lib/contents.php

@@ -45,7 +45,9 @@ function getContents($url, $header = array(), $opts = array()){
 	Debug::log('Reading contents from "' . $url . '"');
 
 	// Initialize cache
-	$cache = Cache::create(Configuration::getConfig('cache', 'type'));
+	$cacheFac = new CacheFactory();
+	$cacheFac->setWorkingDir(PATH_LIB_CACHES);
+	$cache = $cacheFac->create(Configuration::getConfig('cache', 'type'));
 	$cache->setScope('server');
 	$cache->purgeCache(86400); // 24 hours (forced)
 
@@ -270,7 +272,9 @@ function getSimpleHTMLDOMCached($url,
 	Debug::log('Caching url ' . $url . ', duration ' . $duration);
 
 	// Initialize cache
-	$cache = Cache::create(Configuration::getConfig('cache', 'type'));
+	$cacheFac = new CacheFactory();
+	$cacheFac->setWorkingDir(PATH_LIB_CACHES);
+	$cache = $cacheFac->create(Configuration::getConfig('cache', 'type'));
 	$cache->setScope('pages');
 	$cache->purgeCache(86400); // 24 hours (forced)
 

lib/rssbridge.php

@@ -66,7 +66,7 @@ require_once PATH_LIB . 'FormatAbstract.php';
 require_once PATH_LIB . 'BridgeFactory.php';
 require_once PATH_LIB . 'BridgeAbstract.php';
 require_once PATH_LIB . 'FeedExpander.php';
-require_once PATH_LIB . 'Cache.php';
+require_once PATH_LIB . 'CacheFactory.php';
 require_once PATH_LIB . 'Authentication.php';
 require_once PATH_LIB . 'Configuration.php';
 require_once PATH_LIB . 'BridgeCard.php';
@@ -88,7 +88,6 @@ require_once PATH_LIB_VENDOR . 'php-urljoin/src/urljoin.php';
 // Initialize static members
 try {
 	Format::setWorkingDir(PATH_LIB_FORMATS);
-	Cache::setWorkingDir(PATH_LIB_CACHES);
 } catch(Exception $e) {
 	error_log($e);
 	header('Content-type: text/plain', true, 500);