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path: root/newlib/libc/stdio/fseek.c
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Diffstat (limited to 'newlib/libc/stdio/fseek.c')
-rw-r--r--newlib/libc/stdio/fseek.c271
1 files changed, 1 insertions, 270 deletions
diff --git a/newlib/libc/stdio/fseek.c b/newlib/libc/stdio/fseek.c
index 099a95892..34147faff 100644
--- a/newlib/libc/stdio/fseek.c
+++ b/newlib/libc/stdio/fseek.c
@@ -101,21 +101,9 @@ Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
#include <_ansi.h>
#include <reent.h>
#include <stdio.h>
-#include <string.h>
-#include <time.h>
-#include <fcntl.h>
-#include <stdlib.h>
#include <errno.h>
-#include <sys/stat.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.
- */
-
int
_DEFUN(_fseek_r, (ptr, fp, offset, whence),
struct _reent *ptr _AND
@@ -123,264 +111,7 @@ _DEFUN(_fseek_r, (ptr, fp, offset, whence),
long offset _AND
int whence)
{
- _fpos_t _EXFNPTR(seekfn, (struct _reent *, _PTR, _fpos_t, int));
- _fpos_t target;
- _fpos_t curoff = 0;
- size_t n;
-#ifdef __USE_INTERNAL_STAT64
- struct stat64 st;
-#else
- struct stat st;
-#endif
- int havepos;
-
- /* Make sure stdio is set up. */
-
- CHECK_INIT (ptr, fp);
-
- _newlib_flockfile_start (fp);
-
- /* If we've been doing some writing, and we're in append mode
- then we don't really know where the filepos is. */
-
- if (fp->_flags & __SAPP && fp->_flags & __SWR)
- {
- /* So flush the buffer and seek to the end. */
- _fflush_r (ptr, fp);
- }
-
- /* Have to be able to seek. */
-
- if ((seekfn = fp->_seek) == NULL)
- {
- ptr->_errno = ESPIPE; /* ??? */
- _newlib_flockfile_exit (fp);
- return EOF;
- }
-
- /*
- * 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).
- */
- _fflush_r (ptr, fp); /* may adjust seek offset on append stream */
- if (fp->_flags & __SOFF)
- curoff = fp->_offset;
- else
- {
- curoff = seekfn (ptr, fp->_cookie, (_fpos_t) 0, SEEK_CUR);
- if (curoff == -1L)
- {
- _newlib_flockfile_exit (fp);
- return EOF;
- }
- }
- 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 += curoff;
- whence = SEEK_SET;
- havepos = 1;
- break;
-
- case SEEK_SET:
- case SEEK_END:
- havepos = 0;
- break;
-
- default:
- ptr->_errno = EINVAL;
- _newlib_flockfile_exit (fp);
- return (EOF);
- }
-
- /*
- * 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_r (ptr, fp);
- if (fp->_flags & (__SWR | __SRW | __SNBF | __SNPT))
- goto dumb;
- if ((fp->_flags & __SOPT) == 0)
- {
- if (seekfn != __sseek
- || fp->_file < 0
-#ifdef __USE_INTERNAL_STAT64
- || _fstat64_r (ptr, fp->_file, &st)
-#else
- || _fstat_r (ptr, fp->_file, &st)
-#endif
- || (st.st_mode & S_IFMT) != S_IFREG)
- {
- fp->_flags |= __SNPT;
- goto dumb;
- }
-#ifdef HAVE_BLKSIZE
- fp->_blksize = st.st_blksize;
-#else
- fp->_blksize = 1024;
-#endif
- 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
- {
-#ifdef __USE_INTERNAL_STAT64
- if (_fstat64_r (ptr, fp->_file, &st))
-#else
- if (_fstat_r (ptr, fp->_file, &st))
-#endif
- goto dumb;
- target = st.st_size + offset;
- }
- if ((long)target != target)
- {
- ptr->_errno = EOVERFLOW;
- _newlib_flockfile_exit (fp);
- return EOF;
- }
-
- if (!havepos)
- {
- if (fp->_flags & __SOFF)
- curoff = fp->_offset;
- else
- {
- curoff = seekfn (ptr, fp->_cookie, 0L, 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 (target >= curoff && target < curoff + n)
- {
- register int o = target - curoff;
-
- fp->_p = fp->_bf._base + o;
- fp->_r = n - o;
- if (HASUB (fp))
- FREEUB (ptr, fp);
- fp->_flags &= ~__SEOF;
- memset (&fp->_mbstate, 0, sizeof (_mbstate_t));
- _newlib_flockfile_exit (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 (ptr, fp->_cookie, curoff, SEEK_SET) == POS_ERR)
- goto dumb;
- fp->_r = 0;
- fp->_p = fp->_bf._base;
- if (HASUB (fp))
- FREEUB (ptr, fp);
- fp->_flags &= ~__SEOF;
- n = target - curoff;
- if (n)
- {
- if (__srefill_r (ptr, fp) || fp->_r < n)
- goto dumb;
- fp->_p += n;
- fp->_r -= n;
- }
- memset (&fp->_mbstate, 0, sizeof (_mbstate_t));
- _newlib_flockfile_exit (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 (_fflush_r (ptr, fp)
- || seekfn (ptr, fp->_cookie, offset, whence) == POS_ERR)
- {
- _newlib_flockfile_exit (fp);
- return EOF;
- }
- /* success: clear EOF indicator and discard ungetc() data */
- if (HASUB (fp))
- FREEUB (ptr, fp);
- fp->_p = fp->_bf._base;
- fp->_r = 0;
- /* fp->_w = 0; *//* unnecessary (I think...) */
- fp->_flags &= ~__SEOF;
- /* Reset no-optimization flag after successful seek. The
- no-optimization flag may be set in the case of a read
- stream that is flushed which by POSIX/SUSv3 standards,
- means that a corresponding seek must not optimize. The
- optimization is then allowed if no subsequent flush
- is performed. */
- fp->_flags &= ~__SNPT;
- memset (&fp->_mbstate, 0, sizeof (_mbstate_t));
- _newlib_flockfile_end (fp);
- return 0;
+ return _fseeko_r (ptr, fp, offset, whence);
}
#ifndef _REENT_ONLY
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