diff options
Diffstat (limited to 'gnu/lib/libg++/iostream/makebuf.C')
| -rw-r--r-- | gnu/lib/libg++/iostream/makebuf.C | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/gnu/lib/libg++/iostream/makebuf.C b/gnu/lib/libg++/iostream/makebuf.C new file mode 100644 index 000000000000..592f59ec396a --- /dev/null +++ b/gnu/lib/libg++/iostream/makebuf.C @@ -0,0 +1,71 @@ +/* + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by the University of California, Berkeley. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ + +// Modified for GNU iostream by Per Bothner 1991. + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "%W% (Berkeley) %G%"; +#endif /* LIBC_SCCS and not lint */ + +#include "ioprivate.h" +#include "fstream.h" +#include <sys/types.h> +#include <sys/stat.h> + +/* + * Allocate a file buffer, or switch to unbuffered I/O. + * Per the ANSI C standard, ALL tty devices default to line buffered. + * + * As a side effect, we set __SOPT or __SNPT (en/dis-able fseek + * optimisation) right after the _fstat() that finds the buffer size. + */ +int filebuf::doallocate() +{ + register size_t size, couldbetty; + register char *p; + struct stat st; + + if (fd() < 0 || _fstat(fd(), &st) < 0) { + couldbetty = 0; + size = _G_BUFSIZ; +#if 0 + /* do not try to optimise fseek() */ + fp->_flags |= __SNPT; +#endif + } else { + couldbetty = S_ISCHR(st.st_mode); +#if _G_HAVE_ST_BLKSIZE + size = st.st_blksize <= 0 ? _G_BUFSIZ : st.st_blksize; +#else + size = _G_BUFSIZ; +#endif + } +#ifdef USE_MALLOC_BUF + if ((p = malloc(size)) == NULL) { + unbuffered(1); +// fp->_bf._base = fp->_p = fp->_nbuf; +// fp->_bf._size = 1; + return EOF; + } +#else + p = ALLOC_BUF(size); +#endif + setb(p, p+size, 1); + if (couldbetty && _isatty(fd())) + _flags |= _S_LINE_BUF; + return 1; +} |
