/*

* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:  Implementation of CCamBufferShare class.

*                Wrapper around to store and handle sharing of buffer

*                implementing MCameraBuffer interface. Counts references

*                and frees the stored buffer, when no client uses it.

*                

*

*/

// ===========================================================================

// Includes

#include <ecam.h> // MCameraBuffer

#include "camlogging.h"

#include "cambuffershare.h"

// ===========================================================================

// Static data initialisation

#ifdef _DEBUG

  TInt CCamBufferShare::isTotalBufferCount = 0;

#endif // _DEBUG

// ===========================================================================

// Class methods

// ---------------------------------------------------------------------------

// Constructor

// ---------------------------------------------------------------------------

//

CCamBufferShare::CCamBufferShare( MCameraBuffer* aSharedBuffer )

  : iSharedBuffer( aSharedBuffer ),

    iReferenceCount( 0 )

  {

#ifdef _DEBUG

  ++isTotalBufferCount;

#endif // _DEBUG

  }

// ---------------------------------------------------------------------------

// Destructor

//   Private, Release is to be used by clients.

// ---------------------------------------------------------------------------

//

CCamBufferShare::~CCamBufferShare()

  {

  PRINT( _L("Camera => ~CCamBufferShare") );  

  if( iSharedBuffer )

    {

    iSharedBuffer->Release();

    iSharedBuffer = NULL;

    }

#ifdef _DEBUG

  --isTotalBufferCount;

#endif

  PRINT( _L("Camera <= ~CCamBufferShare") );  

  }

// ---------------------------------------------------------------------------

// Return the shared buffer.

// Ownership never transferred to caller.

// ---------------------------------------------------------------------------

//

MCameraBuffer* 

CCamBufferShare::SharedBuffer()

  {

  return iSharedBuffer;

  }

// ---------------------------------------------------------------------------

// Signal, that new client uses this buffer.

// ---------------------------------------------------------------------------

//

void 

CCamBufferShare::Reserve()

  {

  ++iReferenceCount;

  }

// ---------------------------------------------------------------------------

// Signal that one client has stopped using this buffer.

// ---------------------------------------------------------------------------

//

void 

CCamBufferShare::Release()

  {

  --iReferenceCount;

  if( iReferenceCount <= 0 )

    {

    delete this;

    }

  }

#ifdef _DEBUG

// ---------------------------------------------------------------------------

// TotalBufferShareCount <<static>>

//

// Debug method to follow the total amount of shared buffers in use.

// ---------------------------------------------------------------------------

//

TInt 

CCamBufferShare::TotalBufferShareCount()

  {

  return isTotalBufferCount;

  }

#endif // _DEBUG

// end of file