LifeProject/LifeCore/IMemoryStream.h

#ifndef I_MEMORY_STREAM_H__
#define I_MEMORY_STREAM_H__

#include "IDataStream.h"

namespace LifeCore
{
	class IMemoryStream : public LifeCore::IDataStream
	{
	private:
		char* pData;
		size_t position;
		size_t stmLength;
		bool userData;
	public:
		IMemoryStream()
		{
			userData = true;
			pData = 0;
			stmLength = 0;
			position = 0;
		}
		IMemoryStream(size_t size)
		{
			userData = false;
			pData = new char[size];
			stmLength = size;
			position = 0;
		}
		IMemoryStream(char* _pData, size_t dataSize)
		{
			userData = true;
			pData = _pData;
			stmLength = dataSize;
			position = 0;
		}
		~IMemoryStream()
		{
			if(!userData && pData !=0)
			{
				delete[] pData;
			}
		}
		int stride;
		int vertexCount;

		char* GetData()
		{
			return pData;
		}
		void Clear(int val)
		{
			memset(pData, val, stmLength);
		}
		void Close()
		{
		}
		void Reset(char* _pData, size_t dataSize)
		{
			pData = _pData;
			stmLength = dataSize;
			position = 0;
		}
		size_t Read(void* pBuffer, size_t countBytes)
		{
			size_t diff = stmLength - position;
			if(diff <=0 || !countBytes)return 0;
			if(countBytes > diff)
				countBytes = diff;
			memcpy(pBuffer, pData + position, countBytes);
			position+=countBytes;

			return countBytes;
		}

		size_t ReadInt8(char& data)
		{
			return Read(&data, sizeof(char));
		}
		size_t ReadInt16(short& data)
		{
			return Read(&data, sizeof(short));
		}
		size_t ReadInt32(int& data)
		{
			return Read(&data, sizeof(int));
		}

#define DEF_WRITE(type_name)\
	size_t Write(type_name val) \
		{ return Write(&val, sizeof(type_name)); } \

		DEF_WRITE(short);
		DEF_WRITE(int);
		DEF_WRITE(char);
		DEF_WRITE(float);
		DEF_WRITE(double);
		DEF_WRITE(long long);
		DEF_WRITE(unsigned short);
		DEF_WRITE(unsigned int);
		DEF_WRITE(unsigned char);

		size_t Write(const void* pBuffer, size_t countBytes)
		{
			size_t diff = stmLength - position;
			if(diff <=0)return 0;
			//if(countBytes > diff)
			//	countBytes = diff;
			memcpy(pData + position, pBuffer, countBytes);
			position+=countBytes;
			return countBytes;
		}
		void Seek(size_t _position)
		{
			position = _position;
			if(position < 0) position = 0;
			if(position >= stmLength && stmLength !=0) position = stmLength - 1;
		}

		size_t Tell()
		{
			return position;
		}
		size_t Length()
		{
			return stmLength;
		}
		bool CanRead()
		{
			return true;
		}
		bool CanWrite()
		{
			return true;
		}
	};
}

#endif