// ============================================================================
//  Copyright (C) 2001-2011 by Jozef Starosczyk
//  ixen@copyhandler.com
//
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Library General Public License
//  (version 2) as published by the Free Software Foundation;
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU Library General Public
//  License along with this program; if not, write to the
//  Free Software Foundation, Inc.,
//  59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
// ============================================================================
/// @file  TSharedMemory.h
/// @date  2011/05/03
/// @brief Contains shared memory support classes.
// ============================================================================
#ifndef __TSHAREDMEMORY_H__
#define __TSHAREDMEMORY_H__

#include "../libstring/TString.h"
#include "TIpcMutex.h"

namespace chcore
{
	class LIBCHCORE_API TSharedMemory
	{
	public:
		typedef unsigned int shm_size_t;

	public:
		TSharedMemory();
		TSharedMemory(const TSharedMemory&) = delete;
		~TSharedMemory();

		TSharedMemory& operator=(const TSharedMemory&) = delete;

		void Create(const wchar_t* pszName, shm_size_t stSize);
		void Create(const wchar_t* pszName, const string::TString& wstrData);
		void Create(const wchar_t* pszName, const BYTE* pbyData, shm_size_t stSize);

		void Open(const wchar_t* pszName);
		void Close() throw();

		void Read(string::TString& wstrData) const;
		void Write(const string::TString& wstrData);
		void Write(const BYTE* pbyData, shm_size_t stSize);

		// below are the unsafe functions (i.e. not protected with mutex)
		const BYTE* GetData() const;
		BYTE* GetData();
		const BYTE* GetFullData() const;

		shm_size_t GetSharedMemorySize() const;
		shm_size_t GetDataSize() const;

	private:
		HANDLE m_hFileMapping;
		BYTE* m_pMappedMemory;
		shm_size_t m_stSize;     // contains full size of the allocated shared memory (in case we created the memory), size of occupied memory in case we opened the memory.

		mutable TIpcMutex m_mutex;
	};
}

#endif