11dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project/* $OpenBSD: fread.c,v 1.6 2005/08/08 08:05:36 espie 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 <string.h> 361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include <errno.h> 371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#include "local.h" 381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectstatic int 401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectlflush(FILE *fp) 411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 421dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 431dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR)) 441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (__sflush(fp)); 451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (0); 461dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectsize_t 491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Projectfread(void *buf, size_t size, size_t count, FILE *fp) 501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project{ 51a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa size_t resid; 52a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa char *p; 53a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa int r; 54a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa size_t total; 551dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 56a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa /* 57a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * The ANSI standard requires a return value of 0 for a count 58a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * or a size of 0. Peculiarily, it imposes no such requirements 59a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * on fwrite; it only requires fread to be broken. 60a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa */ 61a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa if ((resid = count * size) == 0) 62a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa return (0); 63a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa if (fp->_r < 0) 64a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa fp->_r = 0; 65a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa total = resid; 66a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa p = buf; 671dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 681dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#if 1 /* BIONIC: optimize unbuffered reads */ 691dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (fp->_flags & __SNBF && fp->_ur == 0) 701dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project { 71a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa /* the following comes mainly from __srefill(), with slight 72a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * modifications 73a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa */ 741dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 751dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* make sure stdio is set up */ 761dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (!__sdidinit) 771dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project __sinit(); 781dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 791dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_r = 0; /* largely a convenience for callers */ 801dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 811dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* SysV does not make this test; take it out for compatibility */ 821dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (fp->_flags & __SEOF) 831dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (EOF); 841dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 851dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* if not already reading, have to be reading and writing */ 861dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if ((fp->_flags & __SRD) == 0) { 871dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if ((fp->_flags & __SRW) == 0) { 881dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project errno = EBADF; 891dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags |= __SERR; 901dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (EOF); 911dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 921dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* switch to reading */ 931dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (fp->_flags & __SWR) { 941dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (__sflush(fp)) 951dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (EOF); 961dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags &= ~__SWR; 971dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_w = 0; 981dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_lbfsize = 0; 991dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1001dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags |= __SRD; 1011dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } else { 102a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa /* 103a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * We were reading. If there is an ungetc buffer, 104a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * we must have been reading from that. Drop it, 105a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * restoring the previous buffer (if any). If there 106a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * is anything in that buffer, return. 107a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa */ 1081dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (HASUB(fp)) { 1091dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project FREEUB(fp); 1101dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1111dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1121dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 113a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa /* 114a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * Before reading from a line buffered or unbuffered file, 115a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * flush all line buffered output files, per the ANSI C 116a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa * standard. 117a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa */ 1181dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 1191dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (fp->_flags & (__SLBF|__SNBF)) 1201dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (void) _fwalk(lflush); 1211dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 1221dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project while (resid > 0) { 1231dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project int len = (*fp->_read)(fp->_cookie, p, resid ); 1241dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags &= ~__SMOD; 1251dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (len <= 0) { 1261dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (len == 0) 1271dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags |= __SEOF; 1281dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project else { 1291dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_flags |= __SERR; 1301dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1311dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return ((total - resid) / size); 1321dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1331dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p += len; 1341dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project resid -= len; 1351dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1361dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return (count); 1371dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1381dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project else 1391dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project#endif 1401dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project { 1411dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project while (resid > (size_t)(r = fp->_r)) { 1421dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project (void)memcpy((void *)p, (void *)fp->_p, (size_t)r); 1431dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project fp->_p += r; 1441dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* fp->_r = 0 ... done in __srefill */ 1451dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project p += r; 1461dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project resid -= r; 1471dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project if (__srefill(fp)) { 1481dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project /* no more input: return partial result */ 1491dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project return ((total - resid) / size); 1501dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1511dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1521dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project } 1531dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project 154a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa (void)memcpy((void *)p, (void *)fp->_p, resid); 155a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa fp->_r -= resid; 156a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa fp->_p += resid; 157a910abcd194830d2d113b3e183eb7df4d36cd92eAndré Goddard Rosa return (count); 1581dc9e472e19acfe6dc7f41e429236e7eef7ceda1The Android Open Source Project} 159