static _IO_size_t
_IO_file_xsgetn_maybe_mmap (_IO_FILE *fp, void *data, _IO_size_t n)
{
/* We only get here if this is the first attempt to read something.
Decide which operations to use and then punt to the chosen one. */
decide_maybe_mmap (fp);
return _IO_XSGETN (fp, data, n);
}
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;
}
_IO_size_t
_IO_sgetn (_IO_FILE *fp, void *data, _IO_size_t n)
{
/* FIXME handle putback buffer here! */
return _IO_XSGETN (fp, data, n);
}