73 lines
2.4 KiB
C++
73 lines
2.4 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2013, 2014.
|
|
|
|
This file is part of the Sortix C Library.
|
|
|
|
The Sortix C 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 3 of the License, or (at your
|
|
option) any later version.
|
|
|
|
The Sortix C 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 the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
stdio/fsetdefaultbuf_unlocked.cpp
|
|
Sets up default buffering semantics for a FILE.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
|
|
extern "C" int fsetdefaultbuf_unlocked(FILE* fp)
|
|
{
|
|
char* buf = (char*) malloc(sizeof(char) * BUFSIZ);
|
|
if ( !buf )
|
|
{
|
|
// TODO: Determine whether this is truly what we would want and whether
|
|
// a buffer should be pre-allocated when the FILE is created such that
|
|
// this situation _cannot_ occur.
|
|
|
|
// Alright, we're in a bit of a situation here. Normally, we'd go
|
|
// buffered but we are out of memory. We could either fail, but that
|
|
// would mean subsequent calls such as fgetc and fputc would also fail -
|
|
// however that we are out of memory doesn't mean that IO would also
|
|
// fail. Therefore we'll revert to unbuffered semantics and hope that's
|
|
// good enough.
|
|
|
|
return setvbuf_unlocked(fp, NULL, _IONBF, 0);
|
|
}
|
|
|
|
// Determine the buffering semantics depending on whether the destination is
|
|
// an interactive device or not.
|
|
int mode = fp->buffer_mode;
|
|
if ( mode == -1 )
|
|
{
|
|
#if defined(__is_sortix_kernel)
|
|
mode = _IOLBF;
|
|
#else
|
|
mode = _IOFBF;
|
|
int saved_errno = errno;
|
|
if ( isatty(fileno_unlocked(fp)) )
|
|
mode = _IOLBF;
|
|
errno = saved_errno;
|
|
#endif
|
|
}
|
|
if ( setvbuf_unlocked(fp, buf, mode, BUFSIZ) )
|
|
return fp->flags |= _FILE_STATUS_ERROR, free(buf), -1;
|
|
|
|
// The buffer now belongs to the FILE.
|
|
fp->flags |= _FILE_BUFFER_OWNED;
|
|
fp->buffer_free_indirect = free;
|
|
|
|
return 0;
|
|
}
|