gcc/libstdc++-v3/bits/std_fstream.h

387 lines
11 KiB
C++

// File based streams -*- C++ -*-
// Copyright (C) 1997-1999 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, 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 General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
//
// ISO C++ 14882: 27.8 File-based streams
//
#ifndef _CPP_FSTREAM
#define _CPP_FSTREAM 1
#include <bits/std_istream.h>
#include <bits/std_ostream.h>
#include <bits/basic_file.h>
#include <bits/std_locale.h> // For codecvt
#include <bits/c++threads.h> // For __mutext_type
namespace std {
template<typename _CharT, typename _Traits>
class basic_filebuf : public basic_streambuf<_CharT, _Traits>
{
public:
// 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;
// Non-standard Types:
typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
typedef basic_filebuf<_CharT, _Traits> __filebuf_type;
typedef __basic_file __file_type;
typedef typename _Traits::state_type __state_type;
typedef codecvt<_CharT, char, __state_type> __codecvt_type;
typedef typename __codecvt_type::result __res_type;
friend ios_base; // For sync_with_stdio.
private:
// Data Members:
__file_type* _M_file;
bool _M_last_overflowed; // XXX Needed?
__state_type _M_state_cur;// Current state type for codecvt.
__state_type _M_state_beg;
const __codecvt_type* _M_fcvt; // Cached value from use_facet.
__mutext_type _M_lock;
public:
// Constructors/destructor:
basic_filebuf();
// Non-standard ctor:
basic_filebuf(int __fd, const char* __name = "unknown",
ios_base::openmode __mode = ios_base::in | ios_base::out);
virtual
~basic_filebuf()
{
this->close();
_M_fcvt = NULL;
delete _M_file;
_M_file = NULL;
_M_last_overflowed = false;
}
// Members:
bool
is_open(void) const { return _M_file ? _M_file->is_open() : false; }
__filebuf_type*
open(const char* __s, ios_base::openmode __mode);
__filebuf_type*
close(void);
protected:
// Common initialization code for both ctors goes here.
void
_M_init_filebuf(void);
// Overridden virtual functions:
virtual streamsize
showmanyc(void);
// Stroustrup, 1998, p. 628
// underflow() and uflow() functions are called to get the next
// charater from the real input source when the buffer is empty.
// Buffered input uses underflow()
virtual int_type
underflow(void);
virtual int_type
pbackfail(int_type __c = _Traits::eof());
// NB: For what the standard expects of the overflow function,
// see _M_really_overflow(), below. Because basic_streambuf's
// sputc/sputn call overflow directly, and the complications of
// this implementation's setting of the initial pointers all
// equal to _M_buf when initializing, it seems essential to have
// this in actuality be a helper function that checks for the
// eccentricities of this implementation, and then call
// overflow() if indeed the buffer is full.
virtual int_type
overflow(int_type __c = _Traits::eof());
// Stroustrup, 1998, p 648
// The overflow() function is called to transfer characters to the
// real output destination when the buffer is full. A call to
// overflow(c) outputs the contents of the buffer plus the
// character c.
// 27.5.2.4.5
// Consume some sequence of the characters in the pending sequence.
int_type
_M_really_overflow(int_type __c = _Traits::eof());
virtual __streambuf_type*
setbuf(char_type* __s, streamsize __n)
{
if (!this->is_open() && __s == 0 && __n == 0)
_M_buf_size = 0;
_M_last_overflowed = false;
return this;
}
virtual pos_type
seekoff(off_type __off, ios_base::seekdir __way,
ios_base::openmode __mode = ios_base::in | ios_base::out);
virtual pos_type
seekpos(pos_type __pos,
ios_base::openmode __mode = ios_base::in | ios_base::out);
virtual int
sync(void)
{
bool __testput = _M_out_cur && _M_out_beg < _M_out_end;
if (__testput)
{
// Make sure that libio resyncs its idea of the file position
// with the external file.
_M_file->sync();
// Need to restore current position. This interpreted as
// the position of the external byte sequence (_M_file)
// plus the offset in the current internal buffer
// (_M_out_beg - _M_out_cur)
streamoff __cur = _M_file->seekoff(0, ios_base::cur);
off_type __off = _M_out_cur - _M_out_beg;
this->_M_really_overflow();
_M_file->seekpos(__cur + __off);
}
_M_last_overflowed = false;
return 0;
}
virtual void
imbue(const locale& __loc);
void
_M_output_unshift();
};
typedef basic_filebuf<char> filebuf;
typedef basic_filebuf<wchar_t> wfilebuf;
// 27.8.1.5 Template class basic_ifstream
template<typename _CharT, typename _Traits>
class basic_ifstream : public basic_istream<_CharT, _Traits>
{
public:
// 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;
// Non-standard types:
typedef basic_filebuf<_CharT, _Traits> __filebuf_type;
typedef basic_istream<_CharT, _Traits> __istream_type;
// Constructors/Destructors:
basic_ifstream()
: __istream_type(new __filebuf_type())
{ }
explicit
basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in)
: __istream_type(new __filebuf_type())
{ this->open(__s, __mode); }
~basic_ifstream()
{
delete _M_streambuf;
_M_streambuf = NULL;
}
// Members:
__filebuf_type*
rdbuf() const
{ return static_cast<__filebuf_type*>(_M_streambuf); }
bool
is_open(void) { return rdbuf()->is_open(); }
void
open(const char* __s, ios_base::openmode __mode = ios_base::in)
{
if (rdbuf()->open(__s, __mode | ios_base::in) == NULL)
this->setstate(ios_base::failbit);
}
void
close(void)
{
if (!rdbuf()->close())
this->setstate(ios_base::failbit);
}
};
// 27.8.1.8 Template class basic_ofstream
template<typename _CharT, typename _Traits>
class basic_ofstream : public basic_ostream<_CharT,_Traits>
{
public:
// 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;
// Non-standard types:
typedef basic_filebuf<_CharT, _Traits> __filebuf_type;
typedef basic_ostream<_CharT, _Traits> __ostream_type;
// Constructors:
basic_ofstream()
: __ostream_type(new __filebuf_type())
{ }
explicit
basic_ofstream(const char* __s,
ios_base::openmode __mode = ios_base::out|ios_base::trunc)
: __ostream_type(new __filebuf_type())
{ this->open(__s, __mode); }
~basic_ofstream()
{
delete _M_streambuf;
_M_streambuf = NULL;
}
// Members:
__filebuf_type*
rdbuf(void) const
{ return static_cast<__filebuf_type*>(_M_streambuf); }
bool
is_open(void) { return rdbuf()->is_open(); }
void
open(const char* __s,
ios_base::openmode __mode = ios_base::out | ios_base::trunc)
{
if (!rdbuf()->open(__s, __mode | ios_base::out))
this->setstate (ios_base::failbit);
}
void
close(void)
{
if (!rdbuf()->close())
setstate (ios_base::failbit);
}
};
typedef basic_ofstream<char> ofstream;
typedef basic_ofstream<wchar_t> wofstream;
// 27.8.1.11 Template class basic_fstream
template<typename _CharT, typename _Traits>
class basic_fstream : public basic_iostream<_CharT, _Traits>
{
public:
// 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;
// Non-standard types:
typedef basic_filebuf<_CharT, _Traits> __filebuf_type;
typedef basic_ios<_CharT, _Traits> __ios_type;
typedef basic_iostream<_CharT, _Traits> __iostream_type;
// Constructors/destructor:
basic_fstream()
: __iostream_type(new __filebuf_type())
{ }
explicit
basic_fstream(const char* __s,
ios_base::openmode __mode = ios_base::in | ios_base::out)
: __iostream_type(new __filebuf_type())
{ this->open(__s, __mode); }
~basic_fstream()
{
delete _M_streambuf;
_M_streambuf = NULL;
}
// Members:
__filebuf_type*
rdbuf(void) const
{ return static_cast<__filebuf_type*>(_M_streambuf); }
bool
is_open(void) { return rdbuf()->is_open(); }
void
open(const char* __s,
ios_base::openmode __mode = ios_base::in | ios_base::out)
{
if (!rdbuf()->open(__s, __mode))
setstate (ios_base::failbit);
}
void
close(void)
{
if (!rdbuf()->close())
setstate (ios_base::failbit);
}
};
typedef basic_fstream<char> fstream;
typedef basic_fstream<wchar_t> wfstream;
} // namespace std
#ifdef _GLIBCPP_NO_TEMPLATE_EXPORT
# define export
#ifdef _GLIBCPP_FULLY_COMPLIANT_HEADERS
# include <bits/fstream.tcc>
#endif
#endif
#endif /* _CPP_FSTREAM */