Add support for Memcached/Improve database cache

- Create Cache Driver interface
- Update cache table fields
- Add CacheSessionHandler

src/Core/Cache/DatabaseCacheDriver.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace Friendica\Core\Cache;
+
+use dba;
+use Friendica\Core\Cache;
+use Friendica\Database\DBM;
+use Friendica\Util\DateTimeFormat;
+
+/**
+ * Database Cache Driver
+ *
+ * @author Hypolite Petovan <mrpetovan@gmail.com>
+ */
+class DatabaseCacheDriver implements ICacheDriver
+{
+	public function get($key)
+	{
+		$cache = dba::selectFirst('cache', ['v'], ['`k` = ? AND `expires` >= NOW()`', $key]);
+
+		if (DBM::is_result($cache)) {
+			$cached = $cache['v'];
+			$value = @unserialize($cached);
+
+			// Only return a value if the serialized value is valid.
+			// We also check if the db entry is a serialized
+			// boolean 'false' value (which we want to return).
+			if ($cached === serialize(false) || $value !== false) {
+				return $value;
+			}
+		}
+
+		return null;
+	}
+
+	public function set($key, $value, $duration = Cache::MONTH)
+	{
+		$fields = [
+			'v'       => serialize($value),
+			'expires' => DateTimeFormat::utc('now + ' . Cache::duration($duration) . ' seconds'),
+			'updated' => DateTimeFormat::utcNow()
+		];
+
+		return dba::update('cache', $fields, ['k' => $key], true);
+	}
+
+	public function delete($key)
+	{
+		return dba::delete('cache', ['k' => $key]);
+	}
+
+	public function clear()
+	{
+		return dba::delete('cache', ['`expires` < NOW()']);
+	}
+}

src/Core/Cache/ICacheDriver.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Friendica\Core\Cache;
+
+use Friendica\Core\Cache;
+
+/**
+ * Cache Driver Interface
+ *
+ * @author Hypolite Petovan <mrpetovan@gmail.com>
+ */
+interface ICacheDriver
+{
+	/**
+	 * Fetches cached data according to the key
+	 *
+	 * @param string $key The key to the cached data
+	 *
+	 * @return mixed Cached $value or "null" if not found
+	 */
+	public function get($key);
+
+	/**
+	 * Stores data in the cache identified by the key. The input $value can have multiple formats.
+	 *
+	 * @param string  $key      The cache key
+	 * @param mixed   $value    The value to store
+	 * @param integer $duration The cache lifespan, must be one of the Cache constants
+	 *
+	 * @return bool
+	 */
+	public function set($key, $value, $duration = Cache::MONTH);
+
+
+	/**
+	 * Delete a key from the cache
+	 *
+	 * @param string $key
+	 *
+	 * @return bool
+	 */
+	public function delete($key);
+
+	/**
+	 * Remove outdated data from the cache
+	 *
+	 * @return bool
+	 */
+	public function clear();
+}

src/Core/Cache/MemcacheCacheDriver.php

@@ -0,0 +1,77 @@
+<?php
+
+namespace Friendica\Core\Cache;
+
+use Friendica\BaseObject;
+use Friendica\Core\Cache;
+
+/**
+ * Memcache Cache Driver
+ *
+ * @author Hypolite Petovan <mrpetovan@gmail.com>
+ */
+class MemcacheCacheDriver extends BaseObject implements ICacheDriver
+{
+	/**
+	 * @var Memcache
+	 */
+	private $memcache;
+
+	public function __construct($memcache_host, $memcache_port)
+	{
+		if (!class_exists('Memcache', false)) {
+			throw new \Exception('Memcache class isn\'t available');
+		}
+
+		$this->memcache = new \Memcache();
+
+		if (!$this->memcache->connect($memcache_host, $memcache_port)) {
+			throw new \Exception('Expected Memcache server at ' . $memcache_host . ':' . $memcache_port . ' isn\'t available');
+		}
+	}
+
+	public function get($key)
+	{
+		$return = null;
+
+		// We fetch with the hostname as key to avoid problems with other applications
+		$cached = $this->memcache->get(self::getApp()->get_hostname() . ':' . $key);
+
+		// @see http://php.net/manual/en/memcache.get.php#84275
+		if (is_bool($cached) || is_double($cached) || is_long($cached)) {
+			return $return;
+		}
+
+		$value = @unserialize($cached);
+
+		// Only return a value if the serialized value is valid.
+		// We also check if the db entry is a serialized
+		// boolean 'false' value (which we want to return).
+		if ($cached === serialize(false) || $value !== false) {
+			$return = $value;
+		}
+
+		return $return;
+	}
+
+	public function set($key, $value, $duration = Cache::MONTH)
+	{
+		// We store with the hostname as key to avoid problems with other applications
+		return $this->memcache->set(
+			self::getApp()->get_hostname() . ":" . $key,
+			serialize($value),
+			MEMCACHE_COMPRESSED,
+			Cache::duration($duration)
+		);
+	}
+
+	public function delete($key)
+	{
+		return $this->memcache->delete($key);
+	}
+
+	public function clear()
+	{
+		return true;
+	}
+}

src/Core/Cache/MemcachedCacheDriver.php

@@ -0,0 +1,66 @@
+<?php
+
+namespace Friendica\Core\Cache;
+
+use Friendica\BaseObject;
+use Friendica\Core\Cache;
+
+/**
+ * Memcached Cache Driver
+ *
+ * @author Hypolite Petovan <mrpetovan@gmail.com>
+ */
+class MemcachedCacheDriver extends BaseObject implements ICacheDriver
+{
+	/**
+	 * @var Memcached
+	 */
+	private $memcached;
+
+	public function __construct($memcached_host, $memcached_port)
+	{
+		if (!class_exists('Memcached', false)) {
+			throw new \Exception('Memcached class isn\'t available');
+		}
+
+		$this->memcached = new \Memcached();
+
+		if (!$this->memcached->addServer($memcached_host, $memcached_port)) {
+			throw new \Exception('Expected Memcached server at ' . $memcached_host . ':' . $memcached_port . ' isn\'t available');
+		}
+	}
+
+	public function get($key)
+	{
+		$return = null;
+
+		// We fetch with the hostname as key to avoid problems with other applications
+		$value = $this->memcached->get(self::getApp()->get_hostname() . ':' . $key);
+
+		if ($this->memcached->getResultCode() === \Memcached::RES_SUCCESS) {
+			$return = $value;
+		}
+
+		return $return;
+	}
+
+	public function set($key, $value, $duration = Cache::MONTH)
+	{
+		// We store with the hostname as key to avoid problems with other applications
+		return $this->memcached->set(
+			self::getApp()->get_hostname() . ":" . $key,
+			$value,
+			Cache::duration($duration)
+		);
+	}
+
+	public function delete($key)
+	{
+		return $this->memcached->delete($key);
+	}
+
+	public function clear()
+	{
+		return true;
+	}
+}