streambuf

/*	Copyright (C) 2004 Garrett A. Kajmowicz

	This file is part of the uClibc++ Library.

	This library is free software; you can redistribute it and/or
	modify it under the terms of the GNU Lesser General Public
	License as published by the Free Software Foundation; either
	version 2.1 of the License, or (at your option) any later version.

	This library 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
	Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public
	License along with this library; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <basic_definitions>
#include <locale>
#include <string>
#include <iosfwd>

#ifndef HEADER_STD_STREAMBUF
#define HEADER_STD_STREAMBUF 1

#include <ios>

#pragma GCC visibility push(default)

namespace std{

	template <class charT, class traits> class _UCXXEXPORT basic_streambuf{
	public:
#ifdef __UCLIBCXX_SUPPORT_CDIR__
		friend ios_base::Init::Init();
#endif
	// Types:
		typedef charT				char_type;
		typedef typename traits::int_type	int_type;
		typedef typename traits::pos_type	pos_type;
		typedef typename traits::off_type	off_type;
		typedef traits				traits_type;

		virtual ~basic_streambuf();

		locale pubimbue(const locale &loc);

		locale getloc() const{
			return myLocale;
		}

		basic_streambuf<char_type,traits>* pubsetbuf(char_type* s, streamsize n){
			return setbuf(s,n);
		}
		pos_type pubseekoff(off_type off, 
			typename ios_base::seekdir way, 
			ios_base::openmode which = ios_base::in |
			ios_base::out
			)
		{
			return seekoff(off,way,which);
		}
		pos_type pubseekpos(pos_type sp, ios_base::openmode which = ios_base::in | ios_base::out){
			return seekpos(sp,which);
		}
		int pubsync(){
			return sync();
		}

		streamsize in_avail();

		int_type snextc();

		int_type sbumpc();

		int_type sgetc();

		streamsize sgetn(char_type* s, streamsize n){
			return xsgetn(s,n);
		}

		int_type sputbackc(char_type c);

		int_type sungetc();

		int_type sputc(char_type c);

		streamsize sputn(const char_type* s, streamsize n){
			if(openedFor & ios_base::app){
				seekoff(0, ios_base::end, ios_base::out);
			}
			return xsputn(s, n);
		}

	protected:
		locale myLocale;
		//Pointers for the "get" buffers
		charT * mgbeg;
		charT * mgnext;
		charT * mgend;

		//Pointers for the "put" buffers	
		charT * mpbeg;
		charT * mpnext;
		charT * mpend;

		//In the event of null buffers Lets us know what the buffer is opened for
		ios_base::openmode openedFor;
		
		basic_streambuf();

		basic_streambuf(const basic_streambuf<char, char_traits<char> > &)
			: myLocale(),
			mgbeg(0), mgnext(0), mgend(0), mpbeg(0), mpnext(0), mpend(0),
			openedFor(0)
		{ }
		basic_streambuf<char, char_traits<char> > & operator=(const basic_streambuf<char, char_traits<char> > &){
			return *this;
		}
		
		char_type* eback() const{
			return mgbeg;
		}
		char_type* gptr()  const{
			return mgnext;
		}
		char_type* egptr() const{
			return mgend;
		}
		void gbump(int n){
			mgnext+=n;
		}
		void setg(char_type* gbeg, char_type* gnext, char_type* gend){
			mgbeg = gbeg;
			mgnext = gnext;
			mgend = gend;
		}

		char_type* pbase() const{
			return mpbeg;
		}
		char_type* pptr() const{
			return mpnext;
		}
		char_type* epptr() const{
			return mpend;
		}
		void pbump(int n){
			mpnext+=n;
		}
		void setp(char_type* pbeg, char_type* pend){
			mpbeg = pbeg;
			mpnext  = pbeg;
			mpend = pend;
		}

		virtual void imbue(const locale &loc){
			myLocale = loc;
		}

		//Virtual functions which we will not implement

		virtual basic_streambuf<char_type,traits>* setbuf(char_type* , streamsize){
			return 0;
		}
		virtual pos_type seekoff(off_type , ios_base::seekdir, 
			ios_base::openmode = ios_base::in | ios_base::out)
		{
			return 0;
		}
		virtual pos_type seekpos(pos_type , ios_base::openmode = ios_base::in | ios_base::out){
			return 0;
		}
		virtual int sync(){
			return 0;
		}

		virtual int showmanyc(){
			return 0;
		}
		virtual streamsize xsgetn(char_type* , streamsize ){
			return 0;
		}
		virtual int_type underflow(){
			return traits_type::eof();
		}
		virtual int_type uflow(){
			int_type ret = underflow();
			if (!traits_type::eq_int_type(ret, traits_type::eof()))
				gbump(1);
			return ret;
		}

		virtual int_type pbackfail(int_type c = traits::eof()){
			return c;
		}
		virtual streamsize xsputn(const char_type* c, streamsize n){
			//This function is designed to be replaced by subclasses
			for(streamsize i = 0; i< n; ++i){
				if(sputc(c[i]) == traits::eof()){
					return i;
				}
			}
			return n;
		}
		virtual int_type overflow (int_type c = traits::eof()){
			return c;
		}
	};

	typedef basic_streambuf<char>     streambuf;
#ifdef __UCLIBCXX_HAS_WCHAR__
	typedef basic_streambuf<wchar_t> wstreambuf;
#endif


//Definitions put below to allow for easy expansion of code

	template <class C, class T> basic_streambuf<C, T>::~basic_streambuf(){  }

	template <class C, class T> locale basic_streambuf<C, T>::pubimbue(const locale &loc){
		locale temp = myLocale;
		myLocale = loc;
		return temp;
	}

	template <class C, class T> streamsize basic_streambuf<C, T>::in_avail(){
		if(mgend !=0 && mgnext !=0){
			return mgend - mgnext;
		}
		return showmanyc();
	}

	template <class C, class T> typename basic_streambuf<C, T>::int_type basic_streambuf<C, T>::sbumpc(){
		if(mgbeg == 0 || mgnext == mgend){
			return uflow();
		}
		int_type retval = T::to_int_type(*gptr());
		gbump(1);
		return retval;
	}

	template <class C, class T> typename basic_streambuf<C, T>::int_type basic_streambuf<C, T>::snextc(){
		if(sbumpc() == T::eof() ){
			return T::eof() ;
		}
		return sgetc();
	}

	template <class C, class T> typename basic_streambuf<C, T>::int_type basic_streambuf<C, T>::sgetc(){
		if(mgbeg == 0 || mgnext == mgend){
			return underflow();
		}
		return T::to_int_type(*gptr());
	}

	template <class C, class T> typename basic_streambuf<C, T>::int_type basic_streambuf<C, T>::sputbackc(char_type c){
		if(mgbeg == 0 || mgnext == mgbeg || !T::eq(c, gptr()[-1] )){
			return pbackfail(T::to_int_type(c));
		}
		gbump(-1);
		return T::to_int_type(*gptr());
	}

	template <class C, class T> typename basic_streambuf<C, T>::int_type basic_streambuf<C, T>::sungetc(){
		if(mgbeg == 0 || mgnext == mgbeg){
			return ios_base::failbit;
		}
		gbump(-1);
		return T::to_int_type(*gptr());
	}

	template <class C, class T> typename basic_streambuf<C, T>::int_type basic_streambuf<C, T>::sputc(char_type c){
		if(openedFor & ios_base::app){
			seekoff(0, ios_base::end, ios_base::out);
		}
		if(mpnext < mpend){
			*mpnext = c;
			++mpnext;
		}else{
			return overflow( T::to_int_type(c) );
		}
		return T::to_int_type(c);
	}

	template <class C, class T> basic_streambuf<C, T>::basic_streambuf() 
		: myLocale(),
		mgbeg(0), mgnext(0), mgend(0), mpbeg(0), mpnext(0), mpend(0),
		openedFor(0)
	{ }






#ifdef __UCLIBCXX_EXPAND_STREAMBUF_CHAR__
#ifndef __UCLIBCXX_COMPILE_STREAMBUF__

#ifdef __UCLIBCXX_EXPAND_CONSTRUCTORS_DESTRUCTORS__

	template <> _UCXXEXPORT streambuf::basic_streambuf();
	template <> _UCXXEXPORT streambuf::~basic_streambuf();

#endif //__UCLIBCXX_EXPAND_CONSTRUCTORS_DESTRUCTORS__

	template <> _UCXXEXPORT locale streambuf::pubimbue(const locale &loc);
	template <> _UCXXEXPORT streamsize streambuf::in_avail();
	template <> _UCXXEXPORT streambuf::int_type streambuf::sbumpc();
	template <> _UCXXEXPORT streambuf::int_type streambuf::snextc();
	template <> _UCXXEXPORT streambuf::int_type streambuf::sgetc();
	template <> _UCXXEXPORT streambuf::int_type streambuf::sputbackc(char_type c);
	template <> _UCXXEXPORT streambuf::int_type streambuf::sungetc();
	template <> _UCXXEXPORT streambuf::int_type streambuf::sputc(char_type c);

#endif
#endif





}

#pragma GCC visibility pop

#endif