Refactoring Core class structures ...

src/Core/Lock/Factory/Lock.php

@@ -0,0 +1,147 @@
+<?php
+/**
+ * @copyright Copyright (C) 2010-2021, the Friendica project
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Core\Lock\Factory;
+
+use Friendica\Core\Cache\Factory\Cache;
+use Friendica\Core\Cache\Capability\ICanCacheInMemory;
+use Friendica\Core\Cache\Enum;
+use Friendica\Core\Config\Capability\IManageConfigValues;
+use Friendica\Core\Lock\Capability\ICanLock;
+use Friendica\Core\Lock\Type;
+use Friendica\Database\Database;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Class LockFactory
+ *
+ * @package Friendica\Core\Cache
+ *
+ * A basic class to generate a LockDriver
+ */
+class Lock
+{
+	/**
+	 * @var string The default driver for caching
+	 */
+	const DEFAULT_DRIVER = 'default';
+
+	/**
+	 * @var IManageConfigValues The configuration to read parameters out of the config
+	 */
+	private $config;
+
+	/**
+	 * @var Database The database connection in case that the cache is used the dba connection
+	 */
+	private $dba;
+
+	/**
+	 * @var Cache The memory cache driver in case we use it
+	 */
+	private $cacheFactory;
+
+	/**
+	 * @var LoggerInterface The Friendica Logger
+	 */
+	private $logger;
+
+	public function __construct(Cache $cacheFactory, IManageConfigValues $config, Database $dba, LoggerInterface $logger)
+	{
+		$this->cacheFactory = $cacheFactory;
+		$this->config       = $config;
+		$this->dba          = $dba;
+		$this->logger       = $logger;
+	}
+
+	public function create()
+	{
+		$lock_type = $this->config->get('system', 'lock_driver', self::DEFAULT_DRIVER);
+
+		try {
+			switch ($lock_type) {
+				case Enum\Type::MEMCACHE:
+				case Enum\Type::MEMCACHED:
+				case Enum\Type::REDIS:
+				case Enum\Type::APCU:
+					$cache = $this->cacheFactory->create($lock_type);
+					if ($cache instanceof ICanCacheInMemory) {
+						return new Type\CacheLock($cache);
+					} else {
+						throw new \Exception(sprintf('Incompatible cache driver \'%s\' for lock used', $lock_type));
+					}
+					break;
+
+				case 'database':
+					return new Type\DatabaseLock($this->dba);
+					break;
+
+				case 'semaphore':
+					return new Type\SemaphoreLock();
+					break;
+
+				default:
+					return self::useAutoDriver();
+			}
+		} catch (\Exception $exception) {
+			$this->logger->alert('Driver \'' . $lock_type . '\' failed - Fallback to \'useAutoDriver()\'', ['exception' => $exception]);
+			return self::useAutoDriver();
+		}
+	}
+
+	/**
+	 * This method tries to find the best - local - locking method for Friendica
+	 *
+	 * The following sequence will be tried:
+	 * 1. Semaphore Locking
+	 * 2. Cache Locking
+	 * 3. Database Locking
+	 *
+	 * @return ICanLock
+	 */
+	private function useAutoDriver()
+	{
+		// 1. Try to use Semaphores for - local - locking
+		if (function_exists('sem_get')) {
+			try {
+				return new Type\SemaphoreLock();
+			} catch (\Exception $exception) {
+				$this->logger->warning('Using Semaphore driver for locking failed.', ['exception' => $exception]);
+			}
+		}
+
+		// 2. Try to use Cache Locking (don't use the DB-Cache Locking because it works different!)
+		$cache_type = $this->config->get('system', 'cache_driver', 'database');
+		if ($cache_type != Enum\Type::DATABASE) {
+			try {
+				$cache = $this->cacheFactory->create($cache_type);
+				if ($cache instanceof ICanCacheInMemory) {
+					return new Type\CacheLock($cache);
+				}
+			} catch (\Exception $exception) {
+				$this->logger->warning('Using Cache driver for locking failed.', ['exception' => $exception]);
+			}
+		}
+
+		// 3. Use Database Locking as a Fallback
+		return new Type\DatabaseLock($this->dba);
+	}
+}