src/Core/Lock.php

   1 <?php
   2 /**
   3  * @file src/Core/Lock.php
   4  */
   5 namespace Friendica\Util;
   6
   7 /**
   8  * @file src/Core/Lock.php
   9  * @brief Functions for preventing parallel execution of functions
  10  */
  11
  12 use Friendica\Core\Config;
  13 use Friendica\Core\Lock;
  14
  15 require_once 'include/dba.php';
  16
  17 /**
  18  * @brief This class contain Functions for preventing parallel execution of functions
  19  */
  20 class Lock
  21 {
  22         /**
  23          * @var Lock\ILockDriver;
  24          */
  25         static $driver = null;
  26
  27         public static function init()
  28         {
  29                 switch(Config::get('system', 'lock_driver', 'default')) {
  30                         case 'memcache':
  31                                 self::$driver = new Lock\MemcacheLockDriver();
  32                                 break;
  33                         case 'database':
  34                                 self::$driver = new Lock\DatabaseLockDriver();
  35                                 break;
  36                         case 'semaphore':
  37                                 self::$driver = new Lock\SemaphoreLockDriver();
  38                                 break;
  39                         default:
  40                                 // Determine what's the best/fastest locking driver (default behavior in Friendica)
  41                                 if (function_exists('sem_get') && version_compare(PHP_VERSION, '5.6.1', '>=')) {
  42                                         self::$driver = new Lock\SemaphoreLockDriver();
  43                                 } elseif (Config::get('system', 'cache_driver', 'database') == 'memcache') {
  44                                         self::$driver = new Lock\MemcacheLockDriver();
  45                                 } else {
  46                                         self::$driver = new Lock\DatabaseLockDriver();
  47                                 }
  48                 }
  49         }
  50
  51         /**
  52          * Returns the current cache driver
  53          *
  54          * @return Lock\ILockDriver;
  55          */
  56         private static function getDriver()
  57         {
  58                 if (self::$driver === null) {
  59                         self::init();
  60                 }
  61
  62                 return self::$driver;
  63         }
  64
  65         /**
  66          * @brief Acquires a lock for a given name
  67          *
  68          * @param string  $key Name of the lock
  69          * @param integer $timeout Seconds until we give up
  70          *
  71          * @return boolean Was the lock successful?
  72          */
  73         public static function acquireLock($key, $timeout = 120)
  74         {
  75                 return self::getDriver()->acquireLock($key, $timeout);
  76         }
  77
  78         /**
  79          * @brief Releases a lock if it was set by us
  80          *
  81          * @param string $key Name of the lock
  82          * @return mixed
  83          */
  84         public static function releaseLock($key)
  85         {
  86                 return self::getDriver()->releaseLock($key);
  87         }
  88
  89         /**
  90          * @brief Releases all lock that were set by us
  91          * @return void
  92          */
  93         public static function releaseAll()
  94         {
  95                 self::getDriver()->releaseAll();
  96         }
  97 }