1 /** @file 2 Implementation of setvbuf as declared in <stdio.h>. 3 4 Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR> 5 This program and the accompanying materials are licensed and made available 6 under the terms and conditions of the BSD License that accompanies this 7 distribution. The full text of the license may be found at 8 http://opensource.org/licenses/bsd-license. 9 10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 12 13 Copyright (c) 1990, 1993 14 The Regents of the University of California. All rights reserved. 15 16 This code is derived from software contributed to Berkeley by 17 Chris Torek. 18 19 Redistribution and use in source and binary forms, with or without 20 modification, are permitted provided that the following conditions 21 are met: 22 - Redistributions of source code must retain the above copyright 23 notice, this list of conditions and the following disclaimer. 24 - Redistributions in binary form must reproduce the above copyright 25 notice, this list of conditions and the following disclaimer in the 26 documentation and/or other materials provided with the distribution. 27 - Neither the name of the University nor the names of its contributors 28 may be used to endorse or promote products derived from this software 29 without specific prior written permission. 30 31 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 32 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 33 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 34 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE 35 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 36 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 37 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 38 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 39 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 40 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41 POSSIBILITY OF SUCH DAMAGE. 42 43 NetBSD: setvbuf.c,v 1.17 2003/08/07 16:43:31 agc Exp 44 setvbuf.c 8.2 (Berkeley) 11/16/93 45 **/ 46 #include <LibConfig.h> 47 48 #include <assert.h> 49 #include <errno.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <wchar.h> 53 #include "reentrant.h" 54 #include "local.h" 55 #include <MainData.h> 56 57 /* 58 * Set one of the three kinds of buffering, optionally including 59 * a buffer. 60 */ 61 int 62 setvbuf(FILE *fp, char *buf, int mode, size_t size) 63 { 64 int ret, flags; 65 size_t iosize; 66 int ttyflag; 67 68 _DIAGASSERT(fp != NULL); 69 /* buf may be NULL */ 70 if(fp == NULL) { 71 errno = EINVAL; 72 return (EOF); 73 } 74 75 /* 76 * Verify arguments. The `int' limit on `size' is due to this 77 * particular implementation. Note, buf and size are ignored 78 * when setting _IONBF. 79 */ 80 if (mode != _IONBF) 81 if ((mode != _IOFBF && mode != _IOLBF) || (int)size < 0) 82 return (-1); 83 84 FLOCKFILE(fp); 85 /* 86 * Write current buffer, if any. Discard unread input (including 87 * ungetc data), cancel line buffering, and free old buffer if 88 * malloc()ed. We also clear any eof condition, as if this were 89 * a seek. 90 */ 91 ret = 0; 92 (void)__sflush(fp); 93 if (HASUB(fp)) 94 FREEUB(fp); 95 WCIO_FREE(fp); 96 fp->_r = fp->_lbfsize = 0; 97 flags = fp->_flags; 98 if (flags & __SMBF) 99 free((void *)fp->_bf._base); 100 flags &= ~(__SLBF | __SNBF | __SMBF | __SOPT | __SNPT | __SEOF); 101 102 /* If setting unbuffered mode, skip all the hard work. */ 103 if (mode == _IONBF) 104 goto nbf; 105 106 /* 107 * Find optimal I/O size for seek optimization. This also returns 108 * a `tty flag' to suggest that we check isatty(fd), but we do not 109 * care since our caller told us how to buffer. 110 */ 111 flags |= __swhatbuf(fp, &iosize, &ttyflag); 112 if (size == 0) { 113 buf = NULL; /* force local allocation */ 114 size = iosize; 115 } 116 117 /* Allocate buffer if needed. */ 118 if (buf == NULL) { 119 if ((buf = malloc(size)) == NULL) { 120 /* 121 * Unable to honor user's request. We will return 122 * failure, but try again with file system size. 123 */ 124 ret = -1; 125 if (size != iosize) { 126 size = iosize; 127 buf = malloc(size); 128 } 129 } 130 if (buf == NULL) { 131 /* No luck; switch to unbuffered I/O. */ 132 nbf: 133 fp->_flags = (unsigned short)(flags | __SNBF); 134 fp->_w = 0; 135 fp->_bf._base = fp->_p = fp->_nbuf; 136 fp->_bf._size = 1; 137 FUNLOCKFILE(fp); 138 return (ret); 139 } 140 flags |= __SMBF; 141 } 142 143 /* 144 * Kill any seek optimization if the buffer is not the 145 * right size. 146 * 147 * SHOULD WE ALLOW MULTIPLES HERE (i.e., ok iff (size % iosize) == 0)? 148 */ 149 if (size != iosize) 150 flags |= __SNPT; 151 152 /* 153 * Fix up the FILE fields, and set gMD->cleanup for output flush on 154 * exit (since we are buffered in some way). 155 */ 156 if (mode == _IOLBF) 157 flags |= __SLBF; 158 fp->_flags = (unsigned short)flags; 159 fp->_bf._base = fp->_p = (unsigned char *)buf; 160 fp->_bf._size = (int)size; 161 /* fp->_lbfsize is still 0 */ 162 if (flags & __SWR) { 163 /* 164 * Begin or continue writing: see __swsetup(). Note 165 * that __SNBF is impossible (it was handled earlier). 166 */ 167 if (flags & __SLBF) { 168 fp->_w = 0; 169 fp->_lbfsize = -fp->_bf._size; 170 } else 171 fp->_w = (int)size; 172 } else { 173 /* begin/continue reading, or stay in intermediate state */ 174 fp->_w = 0; 175 } 176 gMD->cleanup = _cleanup; 177 178 FUNLOCKFILE(fp); 179 return (ret); 180 } 181
