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   1  <?php
   2  /**
   3   * Part of the Joomla Framework DI Package
   4   *
   5   * @copyright  Copyright (C) 2013 - 2018 Open Source Matters, Inc. All rights reserved.
   6   * @license    GNU General Public License version 2 or later; see LICENSE
   7   */
   8  
   9  namespace Joomla\DI;
  10  
  11  /**
  12   * Defines the representation of a resource.
  13   *
  14   * @since  2.0.0
  15   * @internal
  16   */
  17  final class ContainerResource
  18  {
  19      /**
  20       * Defines the resource as non-shared
  21       *
  22       * @const  integer
  23       * @since  2.0.0
  24       */
  25      public const NO_SHARE = 0;
  26  
  27      /**
  28       * Defines the resource as shared
  29       *
  30       * @const  integer
  31       * @since  2.0.0
  32       */
  33      public const SHARE = 1;
  34  
  35      /**
  36       * Defines the resource as non-protected
  37       *
  38       * @const  integer
  39       * @since  2.0.0
  40       */
  41      public const NO_PROTECT = 0;
  42  
  43      /**
  44       * Defines the resource as protected
  45       *
  46       * @const  integer
  47       * @since  2.0.0
  48       */
  49      public const PROTECT = 2;
  50  
  51      /**
  52       * The container the resource is assigned to
  53       *
  54       * @var    Container
  55       * @since  2.0.0
  56       */
  57      private $container;
  58  
  59      /**
  60       * The object instance for a shared object
  61       *
  62       * @var    mixed
  63       * @since  2.0.0
  64       */
  65      private $instance;
  66  
  67      /**
  68       * The factory object
  69       *
  70       * @var    callable
  71       * @since  2.0.0
  72       */
  73      private $factory;
  74  
  75      /**
  76       * Flag if the resource is shared
  77       *
  78       * @var    boolean
  79       * @since  2.0.0
  80       */
  81      private $shared = false;
  82  
  83      /**
  84       * Flag if the resource is protected
  85       *
  86       * @var    boolean
  87       * @since  2.0.0
  88       */
  89      private $protected = false;
  90  
  91      /**
  92       * Create a resource representation
  93       *
  94       * @param   Container  $container  The container
  95       * @param   mixed      $value      The resource or its factory closure
  96       * @param   integer    $mode       Resource mode, defaults to Resource::NO_SHARE | Resource::NO_PROTECT
  97       *
  98       * @since   2.0.0
  99       */
 100  	public function __construct(Container $container, $value, int $mode = 0)
 101      {
 102          $this->container = $container;
 103          $this->shared    = ($mode & self::SHARE) === self::SHARE;
 104          $this->protected = ($mode & self::PROTECT) === self::PROTECT;
 105  
 106          if (\is_callable($value))
 107          {
 108              $this->factory = $value;
 109          }
 110          else
 111          {
 112              if ($this->shared)
 113              {
 114                  $this->instance = $value;
 115              }
 116  
 117              if (\is_object($value))
 118              {
 119                  $this->factory = function () use ($value)
 120                  {
 121                      return clone $value;
 122                  };
 123              }
 124              else
 125              {
 126                  $this->factory = function () use ($value)
 127                  {
 128                      return $value;
 129                  };
 130              }
 131          }
 132      }
 133  
 134      /**
 135       * Check whether the resource is shared
 136       *
 137       * @return  boolean
 138       *
 139       * @since   2.0.0
 140       */
 141  	public function isShared(): bool
 142      {
 143          return $this->shared;
 144      }
 145  
 146      /**
 147       * Check whether the resource is protected
 148       *
 149       * @return  boolean
 150       *
 151       * @since   2.0.0
 152       */
 153  	public function isProtected(): bool
 154      {
 155          return $this->protected;
 156      }
 157  
 158      /**
 159       * Get an instance of the resource
 160       *
 161       * If a factory was provided, the resource is created and - if it is a shared resource - cached internally.
 162       * If the resource was provided directly, that resource is returned.
 163       *
 164       * @return  mixed
 165       *
 166       * @since   2.0.0
 167       */
 168  	public function getInstance()
 169      {
 170          $callable = $this->factory;
 171  
 172          if ($this->isShared())
 173          {
 174              if ($this->instance === null)
 175              {
 176                  $this->instance = $callable($this->container);
 177              }
 178  
 179              return $this->instance;
 180          }
 181  
 182          return $callable($this->container);
 183      }
 184  
 185      /**
 186       * Get the factory
 187       *
 188       * @return  callable
 189       *
 190       * @since   2.0.0
 191       */
 192  	public function getFactory(): callable
 193      {
 194          return $this->factory;
 195      }
 196  
 197      /**
 198       * Reset the resource
 199       *
 200       * The instance cache is cleared, so that the next call to get() returns a new instance.
 201       * This has an effect on shared, non-protected resources only.
 202       *
 203       * @return  boolean  True if the resource was reset, false otherwise
 204       *
 205       * @since   2.0.0
 206       */
 207  	public function reset(): bool
 208      {
 209          if ($this->isShared() && !$this->isProtected())
 210          {
 211              $this->instance = null;
 212  
 213              return true;
 214          }
 215  
 216          return false;
 217      }
 218  }