src/Factory/LockFactory.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2021, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Factory;
  23
  24 use Friendica\Core\Cache\Factory\CacheFactory;
  25 use Friendica\Core\Cache\IMemoryCache;
  26 use Friendica\Core\Cache\Enum\Type;
  27 use Friendica\Core\Config\IConfig;
  28 use Friendica\Core\Lock;
  29 use Friendica\Database\Database;
  30 use Psr\Log\LoggerInterface;
  31
  32 /**
  33  * Class LockFactory
  34  *
  35  * @package Friendica\Core\Cache
  36  *
  37  * A basic class to generate a LockDriver
  38  */
  39 class LockFactory
  40 {
  41         /**
  42          * @var string The default driver for caching
  43          */
  44         const DEFAULT_DRIVER = 'default';
  45
  46         /**
  47          * @var IConfig The configuration to read parameters out of the config
  48          */
  49         private $config;
  50
  51         /**
  52          * @var Database The database connection in case that the cache is used the dba connection
  53          */
  54         private $dba;
  55
  56         /**
  57          * @var CacheFactory The memory cache driver in case we use it
  58          */
  59         private $cacheFactory;
  60
  61         /**
  62          * @var LoggerInterface The Friendica Logger
  63          */
  64         private $logger;
  65
  66         public function __construct(CacheFactory $cacheFactory, IConfig $config, Database $dba, LoggerInterface $logger)
  67         {
  68                 $this->cacheFactory = $cacheFactory;
  69                 $this->config       = $config;
  70                 $this->dba          = $dba;
  71                 $this->logger       = $logger;
  72         }
  73
  74         public function create()
  75         {
  76                 $lock_type = $this->config->get('system', 'lock_driver', self::DEFAULT_DRIVER);
  77
  78                 try {
  79                         switch ($lock_type) {
  80                                 case Type::MEMCACHE:
  81                                 case Type::MEMCACHED:
  82                                 case Type::REDIS:
  83                                 case Type::APCU:
  84                                         $cache = $this->cacheFactory->create($lock_type);
  85                                         if ($cache instanceof IMemoryCache) {
  86                                                 return new Lock\CacheLock($cache);
  87                                         } else {
  88                                                 throw new \Exception(sprintf('Incompatible cache driver \'%s\' for lock used', $lock_type));
  89                                         }
  90                                         break;
  91
  92                                 case 'database':
  93                                         return new Lock\DatabaseLock($this->dba);
  94                                         break;
  95
  96                                 case 'semaphore':
  97                                         return new Lock\SemaphoreLock();
  98                                         break;
  99
 100                                 default:
 101                                         return self::useAutoDriver();
 102                         }
 103                 } catch (\Exception $exception) {
 104                         $this->logger->alert('Driver \'' . $lock_type . '\' failed - Fallback to \'useAutoDriver()\'', ['exception' => $exception]);
 105                         return self::useAutoDriver();
 106                 }
 107         }
 108
 109         /**
 110          * This method tries to find the best - local - locking method for Friendica
 111          *
 112          * The following sequence will be tried:
 113          * 1. Semaphore Locking
 114          * 2. Cache Locking
 115          * 3. Database Locking
 116          *
 117          * @return Lock\ILock
 118          */
 119         private function useAutoDriver()
 120         {
 121                 // 1. Try to use Semaphores for - local - locking
 122                 if (function_exists('sem_get')) {
 123                         try {
 124                                 return new Lock\SemaphoreLock();
 125                         } catch (\Exception $exception) {
 126                                 $this->logger->warning('Using Semaphore driver for locking failed.', ['exception' => $exception]);
 127                         }
 128                 }
 129
 130                 // 2. Try to use Cache Locking (don't use the DB-Cache Locking because it works different!)
 131                 $cache_type = $this->config->get('system', 'cache_driver', 'database');
 132                 if ($cache_type != Type::DATABASE) {
 133                         try {
 134                                 $cache = $this->cacheFactory->create($cache_type);
 135                                 if ($cache instanceof IMemoryCache) {
 136                                         return new Lock\CacheLock($cache);
 137                                 }
 138                         } catch (\Exception $exception) {
 139                                 $this->logger->warning('Using Cache driver for locking failed.', ['exception' => $exception]);
 140                         }
 141                 }
 142
 143                 // 3. Use Database Locking as a Fallback
 144                 return new Lock\DatabaseLock($this->dba);
 145         }
 146 }