/* return the pos in the file ; RETURN_FAILURE in case of error */
int
writec_ifile(file_desc_t *fd, char c)
{
unsigned int ibloc;
/* write the char in the buffer */
fd->fds_buf[ibloc_of_pos(fd->fds_pos)] = c;
/* first write in the bloc ? ensure the data bloc allocation */
if (! fd->fds_dirty) {
ibloc = vbloc_of_fbloc(fd->fds_inumber, bloc_of_pos(fd->fds_pos), TRUE);
if (! ibloc) {
return RETURN_FAILURE;
}
fd->fds_dirty = TRUE;
}
/* is the buffer full? */
if (ibloc_of_pos(fd->fds_pos) == BLOC_SIZE-1) {
/* write the buffer */
ibloc = vbloc_of_fbloc(fd->fds_inumber, bloc_of_pos(fd->fds_pos), FALSE);
write_bloc(current_vol, ibloc, fd->fds_buf);
/* read the new buffer */
ibloc = vbloc_of_fbloc(fd->fds_inumber,
bloc_of_pos(fd->fds_pos+1), FALSE);
if (! ibloc)
memset(fd->fds_buf, 0, BLOC_SIZE);
else
read_bloc(current_vol, ibloc, fd->fds_buf);
fd->fds_dirty = FALSE;
}
/* update the file cursor and size */
if (fd->fds_size < fd->fds_pos)
fd->fds_size = fd->fds_pos;
fd->fds_pos++;
/* the position of the written char */
return fd->fds_pos - 1;
}
/*------------------------------
Read a char in a file
------------------------------------------------------------*/
int
readc_ifile(file_desc_t *fd)
{
char c;
/* eof? */
if (fd->fds_pos > fd->fds_size)
return READ_EOF;
/* the data is in the buffer, just return it */
c = fd->fds_buf[ibloc_of_pos(fd->fds_pos)];
/* seek + 1 */
seek_ifile(fd, 1);
return c;
}
