Initial Contribution
This commit is contained in:
The Android Open Source Project
151
libc/stdio/setvbuf.c
Normal file
151
libc/stdio/setvbuf.c
Normal file
@@ -0,0 +1,151 @@
|
||||
/* $OpenBSD: setvbuf.c,v 1.8 2005/08/08 08:05:36 espie Exp $ */
|
||||
/*-
|
||||
* Copyright (c) 1990, 1993
|
||||
* The Regents of the University of California. All rights reserved.
|
||||
*
|
||||
* This code is derived from software contributed to Berkeley by
|
||||
* Chris Torek.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
* 3. Neither the name of the University nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this software
|
||||
* without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
||||
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||||
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
||||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||||
* SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include "local.h"
|
||||
|
||||
/*
|
||||
* Set one of the three kinds of buffering, optionally including
|
||||
* a buffer.
|
||||
*/
|
||||
int
|
||||
setvbuf(FILE *fp, char *buf, int mode, size_t size)
|
||||
{
|
||||
int ret, flags;
|
||||
size_t iosize;
|
||||
int ttyflag;
|
||||
|
||||
/*
|
||||
* Verify arguments. The `int' limit on `size' is due to this
|
||||
* particular implementation. Note, buf and size are ignored
|
||||
* when setting _IONBF.
|
||||
*/
|
||||
if (mode != _IONBF)
|
||||
if ((mode != _IOFBF && mode != _IOLBF) || (int)size < 0)
|
||||
return (EOF);
|
||||
|
||||
/*
|
||||
* Write current buffer, if any. Discard unread input (including
|
||||
* ungetc data), cancel line buffering, and free old buffer if
|
||||
* malloc()ed. We also clear any eof condition, as if this were
|
||||
* a seek.
|
||||
*/
|
||||
ret = 0;
|
||||
(void)__sflush(fp);
|
||||
if (HASUB(fp))
|
||||
FREEUB(fp);
|
||||
WCIO_FREE(fp);
|
||||
fp->_r = fp->_lbfsize = 0;
|
||||
flags = fp->_flags;
|
||||
if (flags & __SMBF)
|
||||
free((void *)fp->_bf._base);
|
||||
flags &= ~(__SLBF | __SNBF | __SMBF | __SOPT | __SNPT | __SEOF);
|
||||
|
||||
/* If setting unbuffered mode, skip all the hard work. */
|
||||
if (mode == _IONBF)
|
||||
goto nbf;
|
||||
|
||||
/*
|
||||
* Find optimal I/O size for seek optimization. This also returns
|
||||
* a `tty flag' to suggest that we check isatty(fd), but we do not
|
||||
* care since our caller told us how to buffer.
|
||||
*/
|
||||
flags |= __swhatbuf(fp, &iosize, &ttyflag);
|
||||
if (size == 0) {
|
||||
buf = NULL; /* force local allocation */
|
||||
size = iosize;
|
||||
}
|
||||
|
||||
/* Allocate buffer if needed. */
|
||||
if (buf == NULL) {
|
||||
if ((buf = malloc(size)) == NULL) {
|
||||
/*
|
||||
* Unable to honor user's request. We will return
|
||||
* failure, but try again with file system size.
|
||||
*/
|
||||
ret = EOF;
|
||||
if (size != iosize) {
|
||||
size = iosize;
|
||||
buf = malloc(size);
|
||||
}
|
||||
}
|
||||
if (buf == NULL) {
|
||||
/* No luck; switch to unbuffered I/O. */
|
||||
nbf:
|
||||
fp->_flags = flags | __SNBF;
|
||||
fp->_w = 0;
|
||||
fp->_bf._base = fp->_p = fp->_nbuf;
|
||||
fp->_bf._size = 1;
|
||||
return (ret);
|
||||
}
|
||||
flags |= __SMBF;
|
||||
}
|
||||
|
||||
/*
|
||||
* Kill any seek optimization if the buffer is not the
|
||||
* right size.
|
||||
*
|
||||
* SHOULD WE ALLOW MULTIPLES HERE (i.e., ok iff (size % iosize) == 0)?
|
||||
*/
|
||||
if (size != iosize)
|
||||
flags |= __SNPT;
|
||||
|
||||
/*
|
||||
* Fix up the FILE fields, and set __cleanup for output flush on
|
||||
* exit (since we are buffered in some way).
|
||||
*/
|
||||
if (mode == _IOLBF)
|
||||
flags |= __SLBF;
|
||||
fp->_flags = flags;
|
||||
fp->_bf._base = fp->_p = (unsigned char *)buf;
|
||||
fp->_bf._size = size;
|
||||
/* fp->_lbfsize is still 0 */
|
||||
if (flags & __SWR) {
|
||||
/*
|
||||
* Begin or continue writing: see __swsetup(). Note
|
||||
* that __SNBF is impossible (it was handled earlier).
|
||||
*/
|
||||
if (flags & __SLBF) {
|
||||
fp->_w = 0;
|
||||
fp->_lbfsize = -fp->_bf._size;
|
||||
} else
|
||||
fp->_w = size;
|
||||
} else {
|
||||
/* begin/continue reading, or stay in intermediate state */
|
||||
fp->_w = 0;
|
||||
}
|
||||
__atexit_register_cleanup(_cleanup);
|
||||
|
||||
return (ret);
|
||||
}
|
||||
Reference in New Issue
Block a user