From 7f90294800cf3cb7ec661c36290c69c5ee4b9186 Mon Sep 17 00:00:00 2001 From: dsl Date: Fri, 4 Mar 2005 16:25:20 +0000 Subject: [PATCH] Re-implement in terms of fseek0() --- lib/libc/stdio/fseek.c | 259 +++++------------------------------------ 1 file changed, 27 insertions(+), 232 deletions(-) diff --git a/lib/libc/stdio/fseek.c b/lib/libc/stdio/fseek.c index 8f07ce58f24c..22fefc35ee22 100644 --- a/lib/libc/stdio/fseek.c +++ b/lib/libc/stdio/fseek.c @@ -1,11 +1,11 @@ -/* $NetBSD: fseek.c,v 1.20 2003/08/07 16:43:25 agc Exp $ */ +/* $NetBSD: fseek.c,v 1.21 2005/03/04 16:25:20 dsl Exp $ */ /*- - * Copyright (c) 1990, 1993 - * The Regents of the University of California. All rights reserved. + * Copyright (c) 2005 The NetBSD Foundation, Inc. + * All rights reserved. * - * This code is derived from software contributed to Berkeley by - * Chris Torek. + * This code is derived from software contributed to The NetBSD Foundation + * by David Laight. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -15,30 +15,26 @@ * 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. + * 3. Neither the name of The NetBSD Foundation 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. + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 #if defined(LIBC_SCCS) && !defined(lint) -#if 0 -static char sccsid[] = "@(#)fseek.c 8.3 (Berkeley) 1/2/94"; -#else -__RCSID("$NetBSD: fseek.c,v 1.20 2003/08/07 16:43:25 agc Exp $"); -#endif +__RCSID("$NetBSD: fseek.c,v 1.21 2005/03/04 16:25:20 dsl Exp $"); #endif /* LIBC_SCCS and not lint */ #include @@ -52,219 +48,18 @@ __RCSID("$NetBSD: fseek.c,v 1.20 2003/08/07 16:43:25 agc Exp $"); #include "reentrant.h" #include "local.h" -#define POS_ERR (-(fpos_t)1) - /* * Seek the given file to the given offset. - * `Whence' must be one of the three SEEK_* macros. + * Zero extend the offset if SEEK_SET to allow access to 4GB files */ int -fseek(fp, offset, whence) - FILE *fp; - long offset; - int whence; +fseek(FILE *fp, long l_offset, int whence) { - fpos_t (*seekfn) __P((void *, fpos_t, int)); - fpos_t target, curoff; - size_t n; - struct stat st; - int havepos; + off_t offset; - _DIAGASSERT(fp != NULL); - -#ifdef __GNUC__ - /* This outrageous construct just to shut up a GCC warning. */ - (void) &curoff; -#endif - - /* make sure stdio is set up */ - if (!__sdidinit) - __sinit(); - - FLOCKFILE(fp); - - /* - * Have to be able to seek. - */ - if ((seekfn = fp->_seek) == NULL) { - errno = ESPIPE; /* historic practice */ - FUNLOCKFILE(fp); - return (-1); - } - - /* - * Change any SEEK_CUR to SEEK_SET, and check `whence' argument. - * After this, whence is either SEEK_SET or SEEK_END. - */ - switch (whence) { - - case SEEK_CUR: - /* - * In order to seek relative to the current stream offset, - * we have to first find the current stream offset a la - * ftell (see ftell for details). - */ - __sflush(fp); /* may adjust seek offset on append stream */ - if (fp->_flags & __SOFF) - curoff = fp->_offset; - else { - curoff = (*seekfn)(fp->_cookie, (fpos_t)0, SEEK_CUR); - if (curoff == -1L) { - FUNLOCKFILE(fp); - return (-1); - } - } - if (fp->_flags & __SRD) { - curoff -= fp->_r; - if (HASUB(fp)) - curoff -= fp->_ur; - } else if (fp->_flags & __SWR && fp->_p != NULL) - curoff += fp->_p - fp->_bf._base; - - offset += (long)curoff; - whence = SEEK_SET; - havepos = 1; - break; - - case SEEK_SET: - case SEEK_END: - curoff = 0; /* XXX just to keep gcc quiet */ - havepos = 0; - break; - - default: - errno = EINVAL; - FUNLOCKFILE(fp); - return (-1); - } - - /* - * Can only optimise if: - * reading (and not reading-and-writing); - * not unbuffered; and - * this is a `regular' Unix file (and hence seekfn==__sseek). - * We must check __NBF first, because it is possible to have __NBF - * and __SOPT both set. - */ - if (fp->_bf._base == NULL) - __smakebuf(fp); - if (fp->_flags & (__SWR | __SRW | __SNBF | __SNPT)) - goto dumb; - if ((fp->_flags & __SOPT) == 0) { - if (seekfn != __sseek || - fp->_file < 0 || fstat(fp->_file, &st) || - !S_ISREG(st.st_mode)) { - fp->_flags |= __SNPT; - goto dumb; - } - fp->_blksize = st.st_blksize; - fp->_flags |= __SOPT; - } - - /* - * We are reading; we can try to optimise. - * Figure out where we are going and where we are now. - */ if (whence == SEEK_SET) - target = offset; - else { - if (fstat(fp->_file, &st)) - goto dumb; - target = st.st_size + offset; - } - - if (!havepos) { - if (fp->_flags & __SOFF) - curoff = fp->_offset; - else { - curoff = (*seekfn)(fp->_cookie, (fpos_t)0, SEEK_CUR); - if (curoff == POS_ERR) - goto dumb; - } - curoff -= fp->_r; - if (HASUB(fp)) - curoff -= fp->_ur; - } - - /* - * Compute the number of bytes in the input buffer (pretending - * that any ungetc() input has been discarded). Adjust current - * offset backwards by this count so that it represents the - * file offset for the first byte in the current input buffer. - */ - if (HASUB(fp)) { - curoff += fp->_r; /* kill off ungetc */ - n = fp->_up - fp->_bf._base; - curoff -= n; - n += fp->_ur; - } else { - n = fp->_p - fp->_bf._base; - curoff -= n; - n += fp->_r; - } - - /* - * If the target offset is within the current buffer, - * simply adjust the pointers, clear EOF, undo ungetc(), - * and return. (If the buffer was modified, we have to - * skip this; see fgetln.c.) - */ - if ((fp->_flags & __SMOD) == 0 && - target >= curoff && target < curoff + n) { - int o = (int)(target - curoff); - - fp->_p = fp->_bf._base + o; - fp->_r = n - o; - if (HASUB(fp)) - FREEUB(fp); - fp->_flags &= ~__SEOF; - FUNLOCKFILE(fp); - return (0); - } - - /* - * The place we want to get to is not within the current buffer, - * but we can still be kind to the kernel copyout mechanism. - * By aligning the file offset to a block boundary, we can let - * the kernel use the VM hardware to map pages instead of - * copying bytes laboriously. Using a block boundary also - * ensures that we only read one block, rather than two. - */ - curoff = target & ~(fp->_blksize - 1); - if ((*seekfn)(fp->_cookie, curoff, SEEK_SET) == POS_ERR) - goto dumb; - fp->_r = 0; - fp->_p = fp->_bf._base; - if (HASUB(fp)) - FREEUB(fp); - fp->_flags &= ~__SEOF; - n = (int)(target - curoff); - if (n) { - if (__srefill(fp) || fp->_r < n) - goto dumb; - fp->_p += n; - fp->_r -= n; - } - FUNLOCKFILE(fp); - return (0); - - /* - * We get here if we cannot optimise the seek ... just - * do it. Allow the seek function to change fp->_bf._base. - */ -dumb: - if (__sflush(fp) || - (*seekfn)(fp->_cookie, (fpos_t)offset, whence) == POS_ERR) { - FUNLOCKFILE(fp); - return (-1); - } - /* success: clear EOF indicator and discard ungetc() data */ - if (HASUB(fp)) - FREEUB(fp); - fp->_p = fp->_bf._base; - fp->_r = 0; - /* fp->_w = 0; */ /* unnecessary (I think...) */ - fp->_flags &= ~__SEOF; - FUNLOCKFILE(fp); - return (0); + offset = (unsigned long)l_offset; + else + offset = l_offset; + return fseeko(fp, offset, whence); }