windows-xp/Source/XPSP1/NT/base/crts/libw32/include/streambuf

// streambuf standard header
#pragma once
#ifndef _STREAMBUF_
#define _STREAMBUF_
#include <xiosbase>

#pragma pack(push,8)
#pragma warning(push,3)
_STD_BEGIN

		// TEMPLATE CLASS basic_streambuf
template<class _Elem, class _Traits>
	class basic_streambuf
	{	// control read/write buffers
	basic_streambuf(const basic_streambuf<_Elem, _Traits>&);	// not defined
	basic_streambuf<_Elem, _Traits>&
		operator=(const basic_streambuf<_Elem, _Traits>&);	// not defined

protected:
	basic_streambuf()
		: _Plocale(_NEW_CRT locale)
		{	// construct with no buffers
		_Init();
		}

	basic_streambuf(_Uninitialized)
		{	// construct uninitialized
		}

public:
	typedef basic_streambuf<_Elem, _Traits> _Myt;
	typedef _Elem char_type;
	typedef _Traits traits_type;

	virtual ~basic_streambuf()
		{	// destroy the object
		_DELETE_CRT(_Plocale);
		}

	typedef typename _Traits::int_type int_type;
	typedef typename _Traits::pos_type pos_type;
	typedef typename _Traits::off_type off_type;

	pos_type pubseekoff(off_type _Off, ios_base::seekdir _Way,
		ios_base::openmode _Mode = ios_base::in | ios_base::out)
		{	// change position by _Off, according to _Way, _Mode
		return (seekoff(_Off, _Way, _Mode));
		}

	pos_type pubseekoff(off_type _Off, ios_base::seek_dir _Way,
		ios_base::open_mode _Mode)
		{	// change position by _Off, according to _Way, _Mode (old style) 
		return (pubseekoff(_Off, (ios_base::seekdir)_Way,
			(ios_base::openmode)_Mode));
		}

	pos_type pubseekpos(pos_type _Pos,
		ios_base::openmode _Mode = ios_base::in | ios_base::out)
		{	// change position to _Pos, according to _Mode
		return (seekpos(_Pos, _Mode));
		}

	pos_type pubseekpos(pos_type _Pos, ios_base::open_mode _Mode)
		{	// change position to _Pos, according to _Mode (old style)
		return (seekpos(_Pos, (ios_base::openmode)_Mode));
		}

	_Myt *pubsetbuf(_Elem *_Buffer, streamsize _Count)
		{	// offer _Buffer to external agent
		return (setbuf(_Buffer, _Count));
		}

	locale pubimbue(const locale &_Newlocale)
		{	// set locale to argument
		locale _Oldlocale = *_Plocale;
		imbue(_Newlocale);
		*_Plocale = _Newlocale;
		return (_Oldlocale);
		}

	locale getloc() const
		{	// get locale
		return (*_Plocale);
		}

	streamsize in_avail()
		{	// return count of buffered input characters
		return (gptr() != 0 && gptr() < egptr()
			? (streamsize)(egptr() - gptr()) : showmanyc());
		}

	int pubsync()
		{	// synchronize with external agent
		return (sync());
		}

	int_type sbumpc()
		{	// get a character and point past it
		return (gptr() != 0 && gptr() < egptr()
			? _Traits::to_int_type(*_Gninc()) : uflow());
		}

	int_type sgetc()
		{	// get a character and don't point past it
		return (gptr() != 0 && gptr() < egptr()
			? _Traits::to_int_type(*gptr()) : underflow());
		}

	streamsize sgetn(_Elem *_Ptr, streamsize _Count)
		{	// get up to _Count characters into array beginning at _Ptr
		return (xsgetn(_Ptr, _Count));
		}

	int_type snextc()
		{	// point to next character and return it
		return (_Traits::eq_int_type(_Traits::eof(), sbumpc())
			? _Traits::eof() : sgetc());
		}

	int_type sputbackc(_Elem _Ch)
		{	// put back _Ch
		return (gptr() != 0 && eback() < gptr()
			&& _Traits::eq(_Ch, gptr()[-1])
			? _Traits::to_int_type(*_Gndec())
			: pbackfail(_Traits::to_int_type(_Ch)));
		}

	void stossc()
		{	// point past a character
		if (gptr() != 0 && gptr() < egptr())
			_Gninc();
		else
			uflow();
		}

	int_type sungetc()
		{	// back up one position
		return (gptr() != 0 && eback() < gptr()
			? _Traits::to_int_type(*_Gndec()) : pbackfail());
		}

	int_type sputc(_Elem _Ch)
		{	// put a character
		return (pptr() != 0 && pptr() < epptr()
			? _Traits::to_int_type(*_Pninc() = _Ch)
			: overflow(_Traits::to_int_type(_Ch)));
		}

	streamsize sputn(const _Elem *_Ptr, streamsize _Count)
		{	// put _Count characters from array beginning at _Ptr
		return (xsputn(_Ptr, _Count));
		}

	void _Lock()
		{	// set the thread lock
		_Mylock._Lock();
		}

	void _Unlock()
		{	// clear the thread lock
		_Mylock._Unlock();
		}

protected:
	_Elem *eback() const
		{	// return beginning of read buffer
		return (*_IGfirst);
		}

	_Elem *gptr() const
		{	// return current position in read buffer
		return (*_IGnext);
		}

	_Elem *pbase() const
		{	// return beginning of write buffer
		return (*_IPfirst);
		}

	_Elem *pptr() const
		{	// return current position in write buffer
		return (*_IPnext);
		}

	_Elem *egptr() const
		{	// return end of read buffer
		return (*_IGnext + *_IGcount);
		}

	void gbump(int _Off)
		{	// alter current position in read buffer by _Off
		*_IGcount -= _Off;
		*_IGnext += _Off;
		}

	void setg(_Elem *_First, _Elem *_Next, _Elem *_Last)
		{	// set pointers for read buffer
		*_IGfirst = _First;
		*_IGnext = _Next;
		*_IGcount = (int)(_Last - _Next);
		}

	_Elem *epptr() const
		{	// return end of write buffer
		return (*_IPnext + *_IPcount);
		}

	_Elem *_Gndec()
		{	// decrement current position in read buffer
		++*_IGcount;
		return (--*_IGnext);
		}

	_Elem *_Gninc()
		{	// increment current position in read buffer
		--*_IGcount;
		return ((*_IGnext)++);
		}

	void pbump(int _Off)
		{	// alter current position in write buffer by _Off
		*_IPcount -= _Off;
		*_IPnext += _Off;
		}

	void setp(_Elem *_First, _Elem *_Last)
		{	// set pointers for write buffer
		*_IPfirst = _First;
		*_IPnext = _First;
		*_IPcount = (int)(_Last - _First);
		}

	void setp(_Elem *_First, _Elem *_Next, _Elem *_Last)
		{	// set pointers for write buffer, extended version
		*_IPfirst = _First;
		*_IPnext = _Next;
		*_IPcount = (int)(_Last - _Next);
		}

	_Elem *_Pninc()
		{	// decrement current position in write buffer
		--*_IPcount;
		return ((*_IPnext)++);
		}

	void _Init()
		{	// initialize buffer parameters for no buffers
		_IGfirst = &_Gfirst, _IPfirst = &_Pfirst;
		_IGnext = &_Gnext, _IPnext = &_Pnext;
		_IGcount = &_Gcount, _IPcount = &_Pcount;
		setp(0, 0), setg(0, 0, 0);
		}

	void _Init(_Elem **_Gf, _Elem **_Gn, int *_Gc,
		_Elem **_Pf, _Elem **_Pn, int *_Pc)
		{	// initialize buffer parameters as specified
		_IGfirst = _Gf, _IPfirst = _Pf;
		_IGnext = _Gn, _IPnext = _Pn;
		_IGcount = _Gc, _IPcount = _Pc;
		}

	virtual int_type overflow(int_type = _Traits::eof())
		{	// put a character to stream (always fail)
		return (_Traits::eof());
		}

	virtual int_type pbackfail(int_type = _Traits::eof())
		{	// put a character back to stream (always fail)
		return (_Traits::eof());
		}

	virtual streamsize showmanyc()
		{	// return count of input characters
		return (0);
		}

	virtual int_type underflow()
		{	// get a character from stream, but don't point past it
		return (_Traits::eof());
		}

	virtual int_type uflow()
		{	// get a character from stream, point past it
		return (_Traits::eq_int_type(_Traits::eof(), underflow())
			? _Traits::eof() : _Traits::to_int_type(*_Gninc()));
		}

	virtual streamsize xsgetn(_Elem * _Ptr, streamsize _Count)
		{	// get _Count characters from stream
		int_type _Meta;
		streamsize _Size, _Copied;

		for (_Copied = 0; 0 < _Count; )
			if (gptr() != 0 && 0 < (_Size = (streamsize)(egptr() - gptr())))
				{	// copy from read buffer
				if (_Count < _Size)
					_Size = _Count;
				_Traits::copy(_Ptr, gptr(), _Size);
				_Ptr += _Size;
				_Copied += _Size;
				_Count -= _Size;
				gbump((int)_Size);
				}
			else if (_Traits::eq_int_type(_Traits::eof(), _Meta = uflow()))
				break;	// end of file, quit
			else
				{	// get a single character
				*_Ptr++ = _Traits::to_char_type(_Meta);
				++_Copied;
				--_Count;
				}

		return (_Copied);
		}

	virtual streamsize xsputn(const _Elem *_Ptr, streamsize _Count)
		{	// put _Count characters to stream
		streamsize _Size, _Copied;

		for (_Copied = 0; 0 < _Count; )
			if (pptr() != 0 && 0 < (_Size = (streamsize)(epptr() - pptr())))
				{	// copy to write buffer
				if (_Count < _Size)
					_Size = _Count;
				_Traits::copy(pptr(), _Ptr, _Size);
				_Ptr += _Size;
				_Copied += _Size;
				_Count -= _Size;
				pbump((int)_Size);
				}
			else if (_Traits::eq_int_type(_Traits::eof(),
				overflow(_Traits::to_int_type(*_Ptr))))
				break;	// single character put failed, quit
			else
				{	// count character successfully put
				++_Ptr;
				++_Copied;
				--_Count;
				}

		return (_Copied);
		}

	virtual pos_type seekoff(off_type, ios_base::seekdir,
		ios_base::openmode = ios_base::in | ios_base::out)
		{	// change position by offset, according to way and mode
		return (streampos(_BADOFF));
		}

	virtual pos_type seekpos(pos_type,
		ios_base::openmode = ios_base::in | ios_base::out)
		{	// change to specified position, according to mode
		return (streampos(_BADOFF));
		}

	virtual _Myt *setbuf(_Elem *, streamsize)
		{	// offer buffer to external agent (do nothing)
		return (this);
		}

	virtual int sync()
		{	// synchronize with external agent (do nothing)
		return (0);
		}

	virtual void imbue(const locale&)
		{	// set locale to argument (do nothing)
		}

private:
	_Mutex _Mylock;	// thread lock
	_Elem *_Gfirst;	// beginning of read buffer
	_Elem *_Pfirst;	// beginning of write buffer
	_Elem **_IGfirst;	// pointer to beginning of read buffer
	_Elem **_IPfirst;	// pointer to beginning of write buffer
	_Elem *_Gnext;	// current position in read buffer
	_Elem *_Pnext;	// current position in write buffer
	_Elem **_IGnext;	// pointer to current position in read buffer
	_Elem **_IPnext;	// pointer to current position in write buffer
	int _Gcount;	// length of read buffer
	int _Pcount;	// length of write buffer
	int *_IGcount;	// pointer to length of read buffer
	int *_IPcount;	// pointer to length of write buffer
	locale *_Plocale;	// pointer to imbued locale object
	};

 #ifdef _DLL_CPPLIB
template class _CRTIMP2 basic_streambuf<char, char_traits<char> >;
template class _CRTIMP2 basic_streambuf<wchar_t, char_traits<wchar_t> >;
 #endif	// _DLL_CPPLIB
_STD_END
#pragma warning(pop)
#pragma pack(pop)

#endif /* _STREAMBUF_ */

/*
* Copyright (c) 1992-2001 by P.J. Plauger.  ALL RIGHTS RESERVED.
 * Consult your license regarding permissions and restrictions.
 V3.10:0009 */