[core] Implemented MemcachedCache (#1000)

* [core] Implemented MemcachedCache

caches/MemcachedCache.php

@@ -0,0 +1,115 @@
+<?php
+class MemcachedCache implements CacheInterface {
+
+	private $scope;
+	private $key;
+	private $conn;
+	private $expiration = 0;
+	private $time = false;
+	private $data = null;
+
+	public function __construct() {
+		if (!extension_loaded('memcached')) {
+			returnServerError('"memcached" extension not loaded. Please check "php.ini"');
+		}
+
+		$host = Configuration::getConfig(get_called_class(), 'host');
+		$port = Configuration::getConfig(get_called_class(), 'port');
+		if (empty($host) && empty($port)) {
+			returnServerError('Configuration for ' . get_called_class() . ' missing. Please check your config.ini.php');
+		} else if (empty($host)) {
+			returnServerError('"host" param is not set for ' . get_called_class() . '. Please check your config.ini.php');
+		} else if (empty($port)) {
+			returnServerError('"port" param is not set for ' . get_called_class() . '. Please check your config.ini.php');
+		} else if (!ctype_digit($port)) {
+			returnServerError('"port" param is invalid for ' . get_called_class() . '. Please check your config.ini.php');
+		}
+
+		$port = intval($port);
+
+		if ($port < 1 || $port > 65535) {
+			returnServerError('"port" param is invalid for ' . get_called_class() . '. Please check your config.ini.php');
+		}
+
+		$conn = new Memcached();
+		$conn->addServer($host, $port) or returnServerError('Could not connect to memcached server');
+		$this->conn = $conn;
+	}
+
+	public function loadData(){
+		if ($this->data) return $this->data;
+		$result = $this->conn->get($this->getCacheKey());
+		if ($result === false) {
+			return false;
+		}
+
+		$this->time = $result['time'];
+		$this->data = $result['data'];
+		return $result['data'];
+	}
+
+	public function saveData($datas){
+		$time = time();
+		$object_to_save = array(
+			'data' => $datas,
+			'time' => $time,
+		);
+		$result = $this->conn->set($this->getCacheKey(), $object_to_save, $this->expiration);
+
+		if($result === false) {
+			returnServerError('Cannot write the cache to memcached server');
+		}
+
+		$this->time = $time;
+
+		return $this;
+	}
+
+	public function getTime(){
+		if ($this->time === false) {
+			$this->loadData();
+		}
+		return $this->time;
+	}
+
+	public function purgeCache($duration){
+		// Note: does not purges cache right now
+		// Just sets cache expiration and leave cache purging for memcached itself
+		$this->expiration = $duration;
+	}
+
+	/**
+	* Set scope
+	* @return self
+	*/
+	public function setScope($scope){
+		$this->scope = $scope;
+		return $this;
+	}
+
+	/**
+	* Set key
+	* @return self
+	*/
+	public function setKey($key){
+		if (!empty($key) && is_array($key)) {
+			$key = array_map('strtolower', $key);
+		}
+		$key = json_encode($key);
+
+		if (!is_string($key)) {
+			throw new \Exception('The given key is invalid!');
+		}
+
+		$this->key = $key;
+		return $this;
+	}
+
+	private function getCacheKey(){
+		if(is_null($this->key)) {
+			returnServerError('Call "setKey" first!');
+		}
+
+		return 'rss_bridge_cache_' . hash('md5', $this->scope . $this->key . 'A');
+	}
+}

config.default.ini.php

@@ -57,3 +57,7 @@ password = ""
 
 [SQLiteCache]
 file = "cache.sqlite"
+
+[MemcachedCache]
+host = "localhost"
+port = 11211