int
__uflow (_IO_FILE *fp)
{
#if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T
if (_IO_vtable_offset (fp) == 0 && _IO_fwide (fp, -1) != -1)
return EOF;
#endif
if (fp->_mode == 0)
_IO_fwide (fp, -1);
if (_IO_in_put_mode (fp))
if (_IO_switch_to_get_mode (fp) == EOF)
return EOF;
if (fp->_IO_read_ptr < fp->_IO_read_end)
return *(unsigned char *) fp->_IO_read_ptr++;
if (_IO_in_backup (fp))
{
_IO_switch_to_main_get_area (fp);
if (fp->_IO_read_ptr < fp->_IO_read_end)
return *(unsigned char *) fp->_IO_read_ptr++;
}
if (_IO_have_markers (fp))
{
if (save_for_backup (fp, fp->_IO_read_end))
return EOF;
}
else if (_IO_have_backup (fp))
_IO_free_backup_area (fp);
return _IO_UFLOW (fp);
}
void
_IO_free_backup_area (_IO_FILE *fp)
{
if (_IO_in_backup (fp))
_IO_switch_to_main_get_area (fp); /* Just in case. */
free (fp->_IO_save_base);
fp->_IO_save_base = NULL;
fp->_IO_save_end = NULL;
fp->_IO_backup_base = NULL;
}
static _IO_size_t
_IO_file_xsgetn_mmap (_IO_FILE *fp, void *data, _IO_size_t n)
{
_IO_size_t have;
char *read_ptr = fp->_IO_read_ptr;
char *s = (char *) data;
have = fp->_IO_read_end - fp->_IO_read_ptr;
if (have < n)
{
if (__glibc_unlikely (_IO_in_backup (fp)))
{
#ifdef _LIBC
s = __mempcpy (s, read_ptr, have);
#else
memcpy (s, read_ptr, have);
s += have;
#endif
n -= have;
_IO_switch_to_main_get_area (fp);
read_ptr = fp->_IO_read_ptr;
have = fp->_IO_read_end - fp->_IO_read_ptr;
}
if (have < n)
{
/* Check that we are mapping all of the file, in case it grew. */
if (__glibc_unlikely (mmap_remap_check (fp)))
/* We punted mmap, so complete with the vanilla code. */
return s - (char *) data + _IO_XSGETN (fp, data, n);
read_ptr = fp->_IO_read_ptr;
have = fp->_IO_read_end - read_ptr;
}
}
if (have < n)
fp->_flags |= _IO_EOF_SEEN;
if (have != 0)
{
have = MIN (have, n);
#ifdef _LIBC
s = __mempcpy (s, read_ptr, have);
#else
memcpy (s, read_ptr, have);
s += have;
#endif
fp->_IO_read_ptr = read_ptr + have;
}
return s - (char *) data;
}
int
_IO_seekmark (_IO_FILE *fp, struct _IO_marker *mark, int delta)
{
if (mark->_sbuf != fp)
return EOF;
if (mark->_pos >= 0)
{
if (_IO_in_backup (fp))
_IO_switch_to_main_get_area (fp);
fp->_IO_read_ptr = fp->_IO_read_base + mark->_pos;
}
else
{
if (!_IO_in_backup (fp))
_IO_switch_to_backup_area (fp);
fp->_IO_read_ptr = fp->_IO_read_end + mark->_pos;
}
return 0;
}
_IO_off64_t
attribute_compat_text_section
_IO_old_file_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
{
_IO_off_t result;
_IO_off64_t delta, new_offset;
long count;
/* POSIX.1 8.2.3.7 says that after a call the fflush() the file
offset of the underlying file must be exact. */
int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end
&& fp->_IO_write_base == fp->_IO_write_ptr);
if (mode == 0)
dir = _IO_seek_cur, offset = 0; /* Don't move any pointers. */
/* Flush unwritten characters.
(This may do an unneeded write if we seek within the buffer.
But to be able to switch to reading, we would need to set
egptr to pptr. That can't be done in the current design,
which assumes file_ptr() is eGptr. Anyway, since we probably
end up flushing when we close(), it doesn't make much difference.)
FIXME: simulate mem-mapped files. */
if (fp->_IO_write_ptr > fp->_IO_write_base || _IO_in_put_mode (fp))
if (_IO_switch_to_get_mode (fp))
return EOF;
if (fp->_IO_buf_base == NULL)
{
/* It could be that we already have a pushback buffer. */
if (fp->_IO_read_base != NULL)
{
free (fp->_IO_read_base);
fp->_flags &= ~_IO_IN_BACKUP;
}
_IO_doallocbuf (fp);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
}
switch (dir)
{
case _IO_seek_cur:
/* Adjust for read-ahead (bytes is buffer). */
offset -= fp->_IO_read_end - fp->_IO_read_ptr;
if (fp->_old_offset == _IO_pos_BAD)
goto dumb;
/* Make offset absolute, assuming current pointer is file_ptr(). */
offset += fp->_old_offset;
dir = _IO_seek_set;
break;
case _IO_seek_set:
break;
case _IO_seek_end:
{
struct stat64 st;
if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode))
{
offset += st.st_size;
dir = _IO_seek_set;
}
else
goto dumb;
}
}
/* At this point, dir==_IO_seek_set. */
/* If we are only interested in the current position we've found it now. */
if (mode == 0)
return offset;
/* If destination is within current buffer, optimize: */
if (fp->_old_offset != _IO_pos_BAD && fp->_IO_read_base != NULL
&& !_IO_in_backup (fp))
{
/* Offset relative to start of main get area. */
_IO_off_t rel_offset = (offset - fp->_old_offset
+ (fp->_IO_read_end - fp->_IO_read_base));
if (rel_offset >= 0)
{
#if 0
if (_IO_in_backup (fp))
_IO_switch_to_main_get_area (fp);
#endif
if (rel_offset <= fp->_IO_read_end - fp->_IO_read_base)
{
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + rel_offset,
fp->_IO_read_end);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
{
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
goto resync;
}
}
#ifdef TODO
/* If we have streammarkers, seek forward by reading ahead. */
if (_IO_have_markers (fp))
{
int to_skip = rel_offset
- (fp->_IO_read_ptr - fp->_IO_read_base);
if (ignore (to_skip) != to_skip)
goto dumb;
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
goto resync;
}
#endif
}
#ifdef TODO
if (rel_offset < 0 && rel_offset >= Bbase () - Bptr ())
{
if (!_IO_in_backup (fp))
_IO_switch_to_backup_area (fp);
gbump (fp->_IO_read_end + rel_offset - fp->_IO_read_ptr);
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
goto resync;
}
#endif
}
#ifdef TODO
_IO_unsave_markers (fp);
#endif
if (fp->_flags & _IO_NO_READS)
goto dumb;
/* Try to seek to a block boundary, to improve kernel page management. */
new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1);
delta = offset - new_offset;
if (delta > fp->_IO_buf_end - fp->_IO_buf_base)
{
new_offset = offset;
delta = 0;
}
result = _IO_SYSSEEK (fp, new_offset, 0);
if (result < 0)
return EOF;
if (delta == 0)
count = 0;
else
{
count = _IO_SYSREAD (fp, fp->_IO_buf_base,
(must_be_exact
? delta : fp->_IO_buf_end - fp->_IO_buf_base));
if (count < delta)
{
/* We weren't allowed to read, but try to seek the remainder. */
offset = count == EOF ? delta : delta-count;
dir = _IO_seek_cur;
goto dumb;
}
}
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta,
fp->_IO_buf_base + count);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
fp->_old_offset = result + count;
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
return offset;
dumb:
_IO_unsave_markers (fp);
result = _IO_SYSSEEK (fp, offset, dir);
if (result != EOF)
{
_IO_mask_flags (fp, 0, _IO_EOF_SEEN);
fp->_old_offset = result;
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
}
return result;
resync:
/* We need to do it since it is possible that the file offset in
the kernel may be changed behind our back. It may happen when
we fopen a file and then do a fork. One process may access the
file and the kernel file offset will be changed. */
if (fp->_old_offset >= 0)
_IO_SYSSEEK (fp, fp->_old_offset, 0);
return offset;
}
_IO_size_t
_IO_file_xsgetn (_IO_FILE *fp, void *data, _IO_size_t n)
{
_IO_size_t want, have;
_IO_ssize_t count;
char *s = data;
want = n;
if (fp->_IO_buf_base == NULL)
{
/* Maybe we already have a push back pointer. */
if (fp->_IO_save_base != NULL)
{
free (fp->_IO_save_base);
fp->_flags &= ~_IO_IN_BACKUP;
}
_IO_doallocbuf (fp);
}
while (want > 0)
{
have = fp->_IO_read_end - fp->_IO_read_ptr;
if (want <= have)
{
memcpy (s, fp->_IO_read_ptr, want);
fp->_IO_read_ptr += want;
want = 0;
}
else
{
if (have > 0)
{
#ifdef _LIBC
s = __mempcpy (s, fp->_IO_read_ptr, have);
#else
memcpy (s, fp->_IO_read_ptr, have);
s += have;
#endif
want -= have;
fp->_IO_read_ptr += have;
}
/* Check for backup and repeat */
if (_IO_in_backup (fp))
{
_IO_switch_to_main_get_area (fp);
continue;
}
/* If we now want less than a buffer, underflow and repeat
the copy. Otherwise, _IO_SYSREAD directly to
the user buffer. */
if (fp->_IO_buf_base
&& want < (size_t) (fp->_IO_buf_end - fp->_IO_buf_base))
{
if (__underflow (fp) == EOF)
break;
continue;
}
/* These must be set before the sysread as we might longjmp out
waiting for input. */
_IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base);
_IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base);
/* Try to maintain alignment: read a whole number of blocks. */
count = want;
if (fp->_IO_buf_base)
{
_IO_size_t block_size = fp->_IO_buf_end - fp->_IO_buf_base;
if (block_size >= 128)
count -= want % block_size;
}
count = _IO_SYSREAD (fp, s, count);
if (count <= 0)
{
if (count == 0)
fp->_flags |= _IO_EOF_SEEN;
else
fp->_flags |= _IO_ERR_SEEN;
break;
}
s += count;
want -= count;
if (fp->_offset != _IO_pos_BAD)
_IO_pos_adjust (fp->_offset, count);
}
}
return n - want;
}
