NetBSD/gnu/lib/libg++/iostream/indstream.C

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// This is part of the iostream library, providing -*- C++ -*- input/output.
// Copyright (C) 1992 Per Bothner.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 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
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free
// Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#ifdef __GNUG__
#pragma implementation
#endif
#include <indstream.h>
indirectbuf::indirectbuf(streambuf *get, streambuf *put, int delete_mode)
: streambuf()
{
_get_stream = get;
_put_stream = put == NULL ? get : put;
_delete_flags = delete_mode;
}
indirectbuf::~indirectbuf()
{
if (_delete_flags & ios::in) delete get_stream();
if (_delete_flags & ios::out) delete put_stream();
}
int indirectbuf::xsputn(const char* s, int n)
{
return put_stream()->sputn(s, n);
}
int indirectbuf::xsgetn(char* s, int n)
{
return get_stream()->sgetn(s, n);
}
int indirectbuf::overflow(int c /* = EOF */)
{
if (c == EOF)
return put_stream()->overflow(c);
else
return put_stream()->sputc(c);
}
int indirectbuf::underflow()
{
return get_stream()->sbumpc();
}
streampos indirectbuf::seekoff(streamoff off, _seek_dir dir, int mode)
{
int ret_val = 0;
int select = mode == 0 ? (ios::in|ios::out) : mode;
streambuf *gbuf = (select & ios::in) ? get_stream() : NULL;
streambuf *pbuf = (select & ios::out) ? put_stream() : NULL;
if (gbuf == pbuf)
ret_val = gbuf->seekoff(off, dir, mode);
else {
if (gbuf)
ret_val = gbuf->seekoff(off, dir, ios::in);
if (pbuf && ret_val != EOF)
ret_val = pbuf->seekoff(off, dir, ios::out);
}
return ret_val;
}
streampos indirectbuf::seekpos(streampos pos, int mode)
{
int ret_val = EOF;
int select = mode == 0 ? (ios::in|ios::out) : mode;
streambuf *gbuf = (select & ios::in) ? get_stream() : NULL;
streambuf *pbuf = (select & ios::out) ? put_stream() : NULL;
if (gbuf == pbuf)
ret_val = gbuf->seekpos(pos, mode);
else {
if (gbuf)
ret_val = gbuf->seekpos(pos, ios::in);
if (pbuf && ret_val != EOF)
ret_val = pbuf->seekpos(pos, ios::out);
}
return ret_val;
}
int indirectbuf::sync()
{
streambuf *gbuf = get_stream();
int ret_val = gbuf->sync();
if (ret_val == EOF) return ret_val;
streambuf *pbuf = put_stream();
if (pbuf != gbuf) return pbuf->sync();
else return ret_val;
}
int indirectbuf::pbackfail(int c)
{
return get_stream()->sputbackc(c);
}