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\IMemoryCache;
  25 use Friendica\Core\Cache\Type;
  26 use Friendica\Core\Config\IConfig;
  27 use Friendica\Core\Lock;
  28 use Friendica\Database\Database;
  29 use Psr\Log\LoggerInterface;
  30
  31 /**
  32  * Class LockFactory
  33  *
  34  * @package Friendica\Core\Cache
  35  *
  36  * A basic class to generate a LockDriver
  37  */
  38 class LockFactory
  39 {
  40         /**
  41          * @var string The default driver for caching
  42          */
  43         const DEFAULT_DRIVER = 'default';
  44
  45         /**
  46          * @var IConfig The configuration to read parameters out of the config
  47          */
  48         private $config;
  49
  50         /**
  51          * @var Database The database connection in case that the cache is used the dba connection
  52          */
  53         private $dba;
  54
  55         /**
  56          * @var CacheFactory The memory cache driver in case we use it
  57          */
  58         private $cacheFactory;
  59
  60         /**
  61          * @var LoggerInterface The Friendica Logger
  62          */
  63         private $logger;
  64
  65         public function __construct(CacheFactory $cacheFactory, IConfig $config, Database $dba, LoggerInterface $logger)
  66         {
  67                 $this->cacheFactory = $cacheFactory;
  68                 $this->config       = $config;
  69                 $this->dba          = $dba;
  70                 $this->logger       = $logger;
  71         }
  72
  73         public function create()
  74         {
  75                 $lock_type = $this->config->get('system', 'lock_driver', self::DEFAULT_DRIVER);
  76
  77                 try {
  78                         switch ($lock_type) {
  79                                 case Type::MEMCACHE:
  80                                 case Type::MEMCACHED:
  81                                 case Type::REDIS:
  82                                 case Type::APCU:
  83                                         $cache = $this->cacheFactory->create($lock_type);
  84                                         if ($cache instanceof IMemoryCache) {
  85                                                 return new Lock\CacheLock($cache);
  86                                         } else {
  87                                                 throw new \Exception(sprintf('Incompatible cache driver \'%s\' for lock used', $lock_type));
  88                                         }
  89                                         break;
  90
  91                                 case 'database':
  92                                         return new Lock\DatabaseLock($this->dba);
  93                                         break;
  94
  95                                 case 'semaphore':
  96                                         return new Lock\SemaphoreLock();
  97                                         break;
  98
  99                                 default:
 100                                         return self::useAutoDriver();
 101                         }
 102                 } catch (\Exception $exception) {
 103                         $this->logger->alert('Driver \'' . $lock_type . '\' failed - Fallback to \'useAutoDriver()\'', ['exception' => $exception]);
 104                         return self::useAutoDriver();
 105                 }
 106         }
 107
 108         /**
 109          * This method tries to find the best - local - locking method for Friendica
 110          *
 111          * The following sequence will be tried:
 112          * 1. Semaphore Locking
 113          * 2. Cache Locking
 114          * 3. Database Locking
 115          *
 116          * @return Lock\ILock
 117          */
 118         private function useAutoDriver()
 119         {
 120                 // 1. Try to use Semaphores for - local - locking
 121                 if (function_exists('sem_get')) {
 122                         try {
 123                                 return new Lock\SemaphoreLock();
 124                         } catch (\Exception $exception) {
 125                                 $this->logger->warning('Using Semaphore driver for locking failed.', ['exception' => $exception]);
 126                         }
 127                 }
 128
 129                 // 2. Try to use Cache Locking (don't use the DB-Cache Locking because it works different!)
 130                 $cache_type = $this->config->get('system', 'cache_driver', 'database');
 131                 if ($cache_type != Type::DATABASE) {
 132                         try {
 133                                 $cache = $this->cacheFactory->create($cache_type);
 134                                 if ($cache instanceof IMemoryCache) {
 135                                         return new Lock\CacheLock($cache);
 136                                 }
 137                         } catch (\Exception $exception) {
 138                                 $this->logger->warning('Using Cache driver for locking failed.', ['exception' => $exception]);
 139                         }
 140                 }
 141
 142                 // 3. Use Database Locking as a Fallback
 143                 return new Lock\DatabaseLock($this->dba);
 144         }
 145 }