Deliver/include/Stream.hpp

#pragma once


#ifndef _SerialPortServer_DLL
#define SERIALPORTSERVER_API	_declspec(dllimport)
#else
#define SERIALPORTSERVER_API	_declspec(dllexport)
#endif


struct StreamData
{
	long	nRefs;				// reference count
	int		nDataLength;		// length of data (including terminator)
	int		nAllocLength;		// length of allocation
	// char data[nAllocLength]

	char *	data ()				// char* to managed data
		{ return (char*) (this+1); }
};


class SERIALPORTSERVER_API Stream
{
public:
	Stream ();

	// copy constructor
	Stream (const Stream & stream);

	// from characters
	Stream (const char * lpsz, int length);

	// from characters
	Stream (const char * lpsz);

	// from unsigned characters
	Stream (const unsigned char * lpsz) { Init(); *this = (const char *) lpsz; }

	// alloc
	Stream (int length);

// Attributes & Operations

	// get data length
	int GetLength () const { return GetData ()->nDataLength; }

	// TRUE if zero length
	BOOL IsEmpty () const { return (GetData ()->nDataLength == 0); }

	// clear contents to empty
	void Empty ();

	// return single character at zero-based index
	char GetAt (int nIndex) const
	{
		return m_pchData[nIndex];
	}

	// return single character at zero-based index
	char operator [] (int nIndex) const { return GetAt (nIndex); }

	// set a single character at zero-based index
	void SetAt (int nIndex, char ch);

	// return pointer to const string
	operator const char * () const { return m_pchData; }

	const char * constBuffer (void) const { return m_pchData; }

	// overloaded assignment

	// ref-counted copy from another Stream
	Stream & operator = (const Stream & stringSrc);

	// copy string content from ANSI string (converts to char)
	Stream & operator = (const char * lpsz);

	// copy string content from unsigned chars
	Stream & operator = (const unsigned char * lpsz) { *this = (const char *) lpsz; return *this; }

	// get pointer to modifiable buffer at least as long as nMinBufLength
	char * GetBuffer (int nMinBufLength);

	// get pointer to modifiable buffer exactly as long as nNewLength
	char * GetBufferSetLength (int nNewLength);

	// Use LockBuffer/UnlockBuffer to turn refcounting off

	// turn refcounting back on
	char * LockBuffer ();
	// turn refcounting off
	void UnlockBuffer ();

// Implementation
public:
	~Stream ();
	int GetAllocLength () const  { return GetData ()->nAllocLength; }

protected:
	char * m_pchData;   // pointer to ref counted string data

protected:
	// implementation helpers
	StreamData * Stream::GetData() const
	{
		return ((StreamData *) m_pchData)-1; 
	}

	void Init ();

	void AllocCopy (Stream & dest, int nCopyLen, int nCopyIndex, int nExtraLen) const;
	void AllocBuffer (int nLen);
	void AssignCopy (int nSrcLen, const char * lpszSrcData);
	void ConcatCopy (int nSrc1Len, const char * lpszSrc1Data, int nSrc2Len, const char * lpszSrc2Data);
	void ConcatInPlace (int nSrcLen, const char * lpszSrcData);
	void CopyBeforeWrite ();
	void AllocBeforeWrite (int nLen);
	void Release ();

	static void Release  (StreamData * pData);
	static void FreeData (StreamData * pData);

};