Civi/Core/Lock/LockManager.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 5                                                  |
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   6  | Copyright CiviCRM LLC (c) 2004-2019                                |
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   8  | This file is a part of CiviCRM.                                    |
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  10  | CiviCRM is free software; you can copy, modify, and distribute it  |
  11  | under the terms of the GNU Affero General Public License           |
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  17  | See the GNU Affero General Public License for more details.        |
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  26  */
  27 namespace Civi\Core\Lock;
  28
  29 use Civi\Core\Resolver;
  30
  31 /**
  32  * Class LockManager
  33  * @package Civi\Core\Lock
  34  *
  35  * The lock-manager allows one to define the lock policy -- i.e. given a
  36  * specific lock, how does one acquire the lock?
  37  */
  38 class LockManager {
  39
  40   private $rules = array();
  41
  42   /**
  43    * @param string $name
  44    *   Symbolic name for the lock. Names generally look like
  45    *   "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}").
  46    *
  47    *   Categories: worker|data|cache|...
  48    *   Component: core|mailing|member|contribute|...
  49    * @return LockInterface
  50    * @throws \CRM_Core_Exception
  51    */
  52   public function create($name) {
  53     $factory = $this->getFactory($name);
  54     if ($factory) {
  55       /** @var LockInterface $lock */
  56       $lock = call_user_func_array($factory, array($name));
  57       return $lock;
  58     }
  59     else {
  60       throw new \CRM_Core_Exception("Lock \"$name\" does not match any rules. Use register() to add more rules.");
  61     }
  62   }
  63
  64   /**
  65    * Create and attempt to acquire a lock.
  66    *
  67    * Note: Be sure to check $lock->isAcquired() to determine whether
  68    * acquisition was successful.
  69    *
  70    * @param string $name
  71    *   Symbolic name for the lock. Names generally look like
  72    *   "worker.mailing.EmailProcessor" ("{category}.{component}.{AdhocName}").
  73    *
  74    *   Categories: worker|data|cache|...
  75    *   Component: core|mailing|member|contribute|...
  76    * @param int|NULL $timeout
  77    *   The number of seconds to wait to get the lock.
  78    *   For a default value, use NULL.
  79    * @return LockInterface
  80    * @throws \CRM_Core_Exception
  81    */
  82   public function acquire($name, $timeout = NULL) {
  83     $lock = $this->create($name);
  84     $lock->acquire($timeout);
  85     return $lock;
  86   }
  87
  88   /**
  89    * @param string $name
  90    *   Symbolic name for the lock.
  91    * @return callable|NULL
  92    */
  93   public function getFactory($name) {
  94     foreach ($this->rules as $rule) {
  95       if (preg_match($rule['pattern'], $name)) {
  96         return Resolver::singleton()->get($rule['factory']);
  97       }
  98     }
  99     return NULL;
 100   }
 101
 102   /**
 103    * Register the lock-factory to use for specific lock-names.
 104    *
 105    * @param string $pattern
 106    *   A regex to match against the lock name.
 107    * @param string|array $factory
 108    *   A callback. The callback should accept a $name parameter.
 109    *   Callbacks will be located using the resolver.
 110    * @return LockManager
 111    * @see Resolver
 112    */
 113   public function register($pattern, $factory) {
 114     $this->rules[] = array(
 115       'pattern' => $pattern,
 116       'factory' => $factory,
 117     );
 118     return $this;
 119   }
 120
 121 }