1b364683ea65e24070c77f1673a8c155665eb894eElliott Hughes/* $OpenBSD: setvbuf.c,v 1.14 2016/09/21 04:38:56 guenther Exp $ */ 21dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/*- 31dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Copyright (c) 1990, 1993 41dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * The Regents of the University of California. All rights reserved. 51dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 61dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * This code is derived from software contributed to Berkeley by 71dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Chris Torek. 81dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 91dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Redistribution and use in source and binary forms, with or without 101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * modification, are permitted provided that the following conditions 111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * are met: 121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 1. Redistributions of source code must retain the above copyright 131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer. 141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 2. Redistributions in binary form must reproduce the above copyright 151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * notice, this list of conditions and the following disclaimer in the 161dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * documentation and/or other materials provided with the distribution. 171dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 3. Neither the name of the University nor the names of its contributors 181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * may be used to endorse or promote products derived from this software 191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * without specific prior written permission. 201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * SUCH DAMAGE. 321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <stdio.h> 351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <stdlib.h> 361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "local.h" 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* 391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Set one of the three kinds of buffering, optionally including 401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * a buffer. 411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 421dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectint 43623b0d05bd924e7fa3c155492695123c87c3a2b1Dmitriy Ivanovsetvbuf(FILE *fp, char *buf, int mode, size_t size) 441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project int ret, flags; 461dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project size_t iosize; 471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project int ttyflag; 481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Verify arguments. The `int' limit on `size' is due to this 511dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * particular implementation. Note, buf and size are ignored 521dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * when setting _IONBF. 531dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 541dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (mode != _IONBF) 551dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if ((mode != _IOFBF && mode != _IOLBF) || (int)size < 0) 561dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (EOF); 571dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 581dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 591dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Write current buffer, if any. Discard unread input (including 601dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * ungetc data), cancel line buffering, and free old buffer if 611dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * malloc()ed. We also clear any eof condition, as if this were 621dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * a seek. 631dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 64623b0d05bd924e7fa3c155492695123c87c3a2b1Dmitriy Ivanov FLOCKFILE(fp); 651dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project ret = 0; 661dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (void)__sflush(fp); 671dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (HASUB(fp)) 681dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project FREEUB(fp); 69623b0d05bd924e7fa3c155492695123c87c3a2b1Dmitriy Ivanov WCIO_FREE(fp); 701dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_r = fp->_lbfsize = 0; 711dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project flags = fp->_flags; 721dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (flags & __SMBF) 73b364683ea65e24070c77f1673a8c155665eb894eElliott Hughes free(fp->_bf._base); 74623b0d05bd924e7fa3c155492695123c87c3a2b1Dmitriy Ivanov flags &= ~(__SLBF | __SNBF | __SMBF | __SOPT | __SNPT | __SEOF); 751dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 761dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* If setting unbuffered mode, skip all the hard work. */ 771dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (mode == _IONBF) 781dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project goto nbf; 791dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 801dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 811dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Find optimal I/O size for seek optimization. This also returns 821dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * a `tty flag' to suggest that we check isatty(fd), but we do not 831dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * care since our caller told us how to buffer. 841dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 851dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project flags |= __swhatbuf(fp, &iosize, &ttyflag); 861dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (size == 0) { 871dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project buf = NULL; /* force local allocation */ 881dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project size = iosize; 891dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 901dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 911dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* Allocate buffer if needed. */ 921dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (buf == NULL) { 931dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if ((buf = malloc(size)) == NULL) { 941dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 951dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Unable to honor user's request. We will return 961dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * failure, but try again with file system size. 971dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 981dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project ret = EOF; 991dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (size != iosize) { 1001dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project size = iosize; 1011dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project buf = malloc(size); 1021dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1031dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1041dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (buf == NULL) { 1051dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* No luck; switch to unbuffered I/O. */ 1061dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectnbf: 1071dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags = flags | __SNBF; 1081dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_w = 0; 1091dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._base = fp->_p = fp->_nbuf; 1101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._size = 1; 111f582340a6a48588aa50da17e1620e8f91b146941Kenny Root FUNLOCKFILE(fp); 1121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (ret); 1131dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1141dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project flags |= __SMBF; 1151dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1161dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 1171dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 11801abeacded873dd835d2115d7c9a9b0b47e75254Elliott Hughes * We're committed to buffering from here, so make sure we've 11901abeacded873dd835d2115d7c9a9b0b47e75254Elliott Hughes * registered to flush buffers on exit. 12001abeacded873dd835d2115d7c9a9b0b47e75254Elliott Hughes */ 12101abeacded873dd835d2115d7c9a9b0b47e75254Elliott Hughes if (!__sdidinit) 12201abeacded873dd835d2115d7c9a9b0b47e75254Elliott Hughes __sinit(); 12301abeacded873dd835d2115d7c9a9b0b47e75254Elliott Hughes 12401abeacded873dd835d2115d7c9a9b0b47e75254Elliott Hughes /* 1251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Kill any seek optimization if the buffer is not the 1261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * right size. 1271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * 1281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * SHOULD WE ALLOW MULTIPLES HERE (i.e., ok iff (size % iosize) == 0)? 1291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 1301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (size != iosize) 1311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project flags |= __SNPT; 1321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 1331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 13401abeacded873dd835d2115d7c9a9b0b47e75254Elliott Hughes * Fix up the FILE fields. 1351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 1361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (mode == _IOLBF) 1371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project flags |= __SLBF; 1381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags = flags; 1391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._base = fp->_p = (unsigned char *)buf; 1401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_bf._size = size; 1411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* fp->_lbfsize is still 0 */ 1421dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (flags & __SWR) { 1431dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* 1441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * Begin or continue writing: see __swsetup(). Note 1451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project * that __SNBF is impossible (it was handled earlier). 1461dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project */ 1471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (flags & __SLBF) { 1481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_w = 0; 1491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_lbfsize = -fp->_bf._size; 1501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } else 1511dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_w = size; 1521dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } else { 1531dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* begin/continue reading, or stay in intermediate state */ 1541dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_w = 0; 1551dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 156677ee5647721df22f13909375d5d0e770a1a80bfElliott Hughes FUNLOCKFILE(fp); 157623b0d05bd924e7fa3c155492695123c87c3a2b1Dmitriy Ivanov 1581dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (ret); 1591dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 160b364683ea65e24070c77f1673a8c155665eb894eElliott HughesDEF_STRONG(setvbuf); 161