#include <cstdlib>
#include <iostream>
#include <cstring>
using namespace std;

#ifdef WIN32
#include < windows.h>
#else
//UNIX/Linux version needs -lrt added to CC command
#include < sys/types.h>
#include < sys/mman.h>
#include < sys/fcntl.h>
#endif //WIN32

class SharedBuffer
{
public:
	SharedBuffer(const char*NameOfMyMapView, int SizeOfBuffer, bool Server = true)
		:m_NameOfMyMapView(new char[strlen(NameOfMyMapView)+1]),
		m_Buffer(NULL), m_SizeOfBuffer(SizeOfBuffer),m_MapHandle(0)
	{
		strcpy(m_NameOfMyMapView, NameOfMyMapView);
#ifdef WIN32
		if (Server)
		{
			m_MapHandle = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0, m_SizeOfBuffer, m_NameOfMyMapView);
			if (m_MapHandle != INVALID_HANDLE_VALUE)
				m_Buffer = (char*)MapViewOfFile(m_MapHandle, FILE_MAP_ALL_ACCESS, 0, 0, m_SizeOfBuffer);
			else m_MapHandle = NULL;
		}
		else
		{
			m_MapHandle = OpenFileMapping(FILE_MAP_ALL_ACCESS, TRUE, m_NameOfMyMapView);
			if (m_MapHandle != INVALID_HANDLE_VALUE)
				m_Buffer = (char*)MapViewOfFile(m_MapHandle, FILE_MAP_ALL_ACCESS, 0, 0, m_SizeOfBuffer);
			else m_MapHandle = NULL;
		}
#else
		m_MapHandle = shm_open(m_NameOfMyMapView, O_RDWR|O_CREAT, 0);
		if (m_MapHandle != -1)
		{
			ftruncate(m_MapHandle, m_SizeOfBuffer);
			m_Buffer = (char*)mmap(NULL, m_SizeOfBuffer, PROT_READ, MAP_SHARED, m_MapHandle , 0);
		}
		else m_MapHandle = 0;
#endif //WIN32
	}
	~SharedBuffer()
	{
		if (m_MapHandle)
		{
#ifdef WIN32
			UnmapViewOfFile(m_Buffer);
			CloseHandle(m_MapHandle);
#else
			munmap(m_Buffer, m_SizeOfBuffer);
			shm_unlink(m_NameOfMyMapView);
#endif //WIN32
		}
		delete m_NameOfMyMapView;
	}
	char* GetBuffer() {return m_Buffer;}
private:
	char* m_NameOfMyMapView;
	char* m_Buffer;
	const int m_SizeOfBuffer;
	bool m_Server;
#ifdef WIN32
	HANDLE m_MapHandle;
#else
	int m_MapHandle;
#endif //WIN32
};