/** Transform data to smallest possible of (int32, int16, int8).
* For example, we may have generated an int32 array due to user options
* (e.g., %option align), but if the maximum value in that array
* is 80 (for example), then we can serialize it with only 1 byte per int.
* This is NOT the same as compressed DFA tables. We're just trying
* to save storage space here.
*
* @param tbl the table to be compressed
*/
void yytbl_data_compress (struct yytbl_data *tbl)
{
flex_int32_t i, total_len;
size_t newsz;
struct yytbl_data newtbl;
yytbl_data_init (&newtbl, tbl->td_id);
newtbl.td_hilen = tbl->td_hilen;
newtbl.td_lolen = tbl->td_lolen;
newtbl.td_flags = tbl->td_flags;
newsz = min_int_size (tbl);
if (newsz == YYTDFLAGS2BYTES (tbl->td_flags))
/* No change in this table needed. */
return;
if (newsz > YYTDFLAGS2BYTES (tbl->td_flags)) {
flex_die (_("detected negative compression"));
return;
}
total_len = yytbl_calc_total_len (tbl);
newtbl.td_data = calloc ((size_t) total_len, newsz);
newtbl.td_flags = (flex_uint16_t)
(TFLAGS_CLRDATA (newtbl.td_flags) | BYTES2TFLAG (newsz));
for (i = 0; i < total_len; i++) {
flex_int32_t g;
g = yytbl_data_geti (tbl, i);
yytbl_data_seti (&newtbl, i, g);
}
/* Now copy over the old table */
free (tbl->td_data);
*tbl = newtbl;
}
/** Calculate the number of bytes needed to hold the largest
* absolute value in this data array.
* @param tbl the data table
* @return sizeof(n) where n in {flex_int8_t, flex_int16_t, flex_int32_t}
*/
static size_t min_int_size (struct yytbl_data *tbl)
{
flex_uint32_t i, total_len;
flex_int32_t max = 0;
total_len = yytbl_calc_total_len (tbl);
for (i = 0; i < total_len; i++) {
flex_int32_t n;
n = abs (yytbl_data_geti (tbl, i));
if (n > max)
max = n;
}
if (max <= INT8_MAX)
return sizeof (flex_int8_t);
else if (max <= INT16_MAX)
return sizeof (flex_int16_t);
else
return sizeof (flex_int32_t);
}
/** Write this table.
* @param out the file writer
* @param td table data to be written
* @return -1 on error, or bytes written on success.
*/
int yytbl_data_fwrite (struct yytbl_writer *wr, struct yytbl_data *td)
{
int rv;
flex_int32_t bwritten = 0;
flex_int32_t i, total_len;
fpos_t pos;
if ((rv = yytbl_write16 (wr, td->td_id)) < 0)
return -1;
bwritten += rv;
if ((rv = yytbl_write16 (wr, td->td_flags)) < 0)
return -1;
bwritten += rv;
if ((rv = yytbl_write32 (wr, td->td_hilen)) < 0)
return -1;
bwritten += rv;
if ((rv = yytbl_write32 (wr, td->td_lolen)) < 0)
return -1;
bwritten += rv;
total_len = yytbl_calc_total_len (td);
for (i = 0; i < total_len; i++) {
switch (YYTDFLAGS2BYTES (td->td_flags)) {
case sizeof (flex_int8_t):
rv = yytbl_write8 (wr, yytbl_data_geti (td, i));
break;
case sizeof (flex_int16_t):
rv = yytbl_write16 (wr, yytbl_data_geti (td, i));
break;
case sizeof (flex_int32_t):
rv = yytbl_write32 (wr, yytbl_data_geti (td, i));
break;
default:
flex_die (_("invalid td_flags detected"));
}
if (rv < 0) {
flex_die (_("error while writing tables"));
return -1;
}
bwritten += rv;
}
/* Sanity check */
if (bwritten != (int) (12 + total_len * YYTDFLAGS2BYTES (td->td_flags))) {
flex_die (_("insanity detected"));
return -1;
}
/* add padding */
if ((rv = yytbl_write_pad64 (wr)) < 0) {
flex_die (_("pad64 failed"));
return -1;
}
bwritten += rv;
/* Now go back and update the th_hsize member */
if (fgetpos (wr->out, &pos) != 0
|| fsetpos (wr->out, &(wr->th_ssize_pos)) != 0
|| yytbl_write32 (wr, wr->total_written) < 0
|| fsetpos (wr->out, &pos)) {
flex_die (_("get|set|fwrite32 failed"));
return -1;
}
else
/* Don't count the int we just wrote. */
wr->total_written -= sizeof (flex_int32_t);
return bwritten;
}
