text: /*
   *  Copyright (c) 2017, The OpenThread Authors.
   *  All rights reserved.
   *
   *  Redistribution and use in source and binary forms, with or without
   *  modification, are permitted provided that the following conditions are met:
   *  1. Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   *  2. Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution.
   *  3. Neither the name of the copyright holder nor the
   *     names of its contributors may be used to endorse or promote products
   *     derived from this software without specific prior written permission.
   *
   *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
   *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   *  POSSIBILITY OF SUCH DAMAGE.
   */
  
  /**
   * @file
   *   This file includes definitions for locator class for OpenThread objects.
   */
  
  #ifndef LOCATOR_HPP_
  #define LOCATOR_HPP_
  
  #include <openthread/config.h>
  
  #include <openthread/types.h>
  
  #include "openthread-core-config.h"
  #include "openthread-single-instance.h"
  
  namespace ot {
  
  class ThreadNetif;
  class MeshForwarder;
  class TaskletScheduler;
  namespace Ip6 { class Ip6; }
  
  /**
   * @addtogroup core-locator
   *
   * @brief
   *   This module includes definitions for locator base class for OpenThread objects.
   *
   * @{
   *
   */
  
  /**
   * This template class implements the base locator for OpenThread objects.
   *
   */
  template <typename Type>
  class Locator
  {
  protected:
      /**
       * This constructor initializes the locator.
       *
       * @param[in]  aObject  A reference to the object.
       *
       */
      Locator(Type &aObject)
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
          : mLocatorObject(aObject)
  #endif
      {
          OT_UNUSED_VARIABLE(aObject);
      }
  
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
      Type &mLocatorObject;
  #endif
  };
  
  /**
   * This class implements a locator for ThreadNetif object.
   *
   */
  class ThreadNetifLocator: private Locator<ThreadNetif>
  {
  public:
      /**
       * This method returns a reference to the thread network interface.
       *
       * @returns   A reference to the thread network interface.
       *
       */
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
      ThreadNetif &GetNetif(void) const { return mLocatorObject; }
  #else
      ThreadNetif &GetNetif(void) const { return otGetThreadNetif(); }
  #endif
  
      /**
       * This method returns the pointer to the parent otInstance structure.
       *
       * @returns The pointer to the parent otInstance structure, or NULL if the instance has been finalized.
       *
       */
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
      otInstance *GetInstance(void) const;
  #else
      otInstance *GetInstance(void) const { return otGetInstance(); }
  #endif
  
  protected:
      /**
       * This constructor initializes the object.
       *
       * @param[in]  aThreadNetif  A reference to the thread network interface.
       *
       */
      ThreadNetifLocator(ThreadNetif &aThreadNetif): Locator(aThreadNetif) { }
  };
  
  /**
   * This class implements a locator for MeshForwarder object.
   *
   */
  class MeshForwarderLocator: private Locator<MeshForwarder>
  {
  public:
      /**
       * This method returns a reference to the MeshForwarder.
       *
       * @returns   A reference to the MeshForwarder.
       *
       */
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
      MeshForwarder &GetMeshForwarder(void) const { return mLocatorObject; }
  #else
      MeshForwarder &GetMeshForwarder(void) const { return otGetMeshForwarder(); }
  #endif
  
      /**
       * This method returns the pointer to the parent otInstance structure.
       *
       * @returns The pointer to the parent otInstance structure, or NULL if the instance has been finalized.
       *
       */
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
      otInstance *GetInstance(void) const;
  #else
      otInstance *GetInstance(void) const { return otGetInstance(); }
  #endif
  
  protected:
      /**
       * This constructor initializes the object.
       *
       * @param[in]  aMeshForwarder  A reference to the MeshForwarder.
       *
       */
      MeshForwarderLocator(MeshForwarder &aMeshForwarder): Locator(aMeshForwarder) { }
  };
  
  /**
   * This class implements a locator for Ip6 object.
   *
   */
  class Ip6Locator: private Locator<Ip6::Ip6>
  {
  public:
      /**
       * This method returns a reference to the Ip6.
       *
       * @returns   A reference to the Ip6.
       *
       */
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
      Ip6::Ip6 &GetIp6(void) const { return mLocatorObject; }
  #else
      Ip6::Ip6 &GetIp6(void) const { return otGetIp6(); }
  #endif
  
      /**
       * This method returns the pointer to the parent otInstance structure.
       *
       * @returns The pointer to the parent otInstance structure, or NULL if the instance has been finalized.
       *
       */
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
      otInstance *GetInstance(void) const;
  #else
      otInstance *GetInstance(void) const { return otGetInstance(); }
  #endif
  
  protected:
      /**
       * This constructor initializes the object.
       *
       * @param[in]  aIp6  A reference to the Ip6.
       *
       */
      Ip6Locator(Ip6::Ip6 &aIp6): Locator(aIp6) { }
  };
  
  /**
   * This class implements locator for  otInstance object
   *
   */
  class InstanceLocator
  {
  public:
      /**
       * This method returns the pointer to the parent otInstance structure.
       *
       * @returns The pointer to the parent otInstance structure, or NULL if the instance has been finalized.
       *
       */
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
      otInstance *GetInstance(void) const { return mInstance; }
  #else
      otInstance *GetInstance(void) const { return otGetInstance(); }
  #endif
  
  protected:
      /**
       * This constructor initializes the object.
       *
       * @param[in]  aInstance  A pointer to the otInstance.
       *
       */
      InstanceLocator(otInstance *aInstance)
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
          : mInstance(aInstance)
  #endif
      {
          OT_UNUSED_VARIABLE(aInstance);
      }
  
  private:
  #if OPENTHREAD_ENABLE_MULTIPLE_INSTANCES
      otInstance *mInstance;
  #endif
  };
  
  /**
   * @}
   *
   */
  
  }  // namespace ot
  
  #endif  // LOCATOR_HPP_
  