void simplify_astates() /* simplifies the alternating automaton */
{
ATrans *t;
int i, *acc = make_set(-1, 0); /* no state is accessible initially */
for (t = transition[0]; t; t = t->nxt, i = 0)
{
merge_sets(acc, t->to, 0); /* all initial states are accessible */
}
for (i = node_id - 1; i > 0; i--)
{
if (!in_set(acc, i)) /* frees unaccessible states */
{
label[i] = ZN;
free_atrans(transition[i], 1);
transition[i] = (ATrans *)0;
continue;
}
astate_count++;
simplify_atrans(&transition[i]);
for (t = transition[i]; t; t = t->nxt)
{
merge_sets(acc, t->to, 0);
}
}
tfree(acc);
}
Datum hll_sum(PG_FUNCTION_ARGS) {
MemoryContext aggctx;
MemoryContext tmpcontext;
MemoryContext oldcontext;
dmerge_state *state;
uint32_t *value;
uLongf dest_size = HLL_LEN * 4;
int unpack_res;
int count;
int i;
bytea *data = PG_GETARG_BYTEA_P(1);
if (!AggCheckCallContext(fcinfo, &aggctx))
ereport(ERROR,
(errcode(ERRCODE_DATA_EXCEPTION),
errmsg("hll_sum outside transition context")));
if ( PG_ARGISNULL(0) ) {
tmpcontext = AllocSetContextCreate(aggctx,
"hll_sum",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
oldcontext = MemoryContextSwitchTo(tmpcontext);
state = (dmerge_state *) palloc(sizeof(dmerge_state));
MemoryContextSwitchTo(oldcontext);
value = state->state;
} else {
state = (dmerge_state *) PG_GETARG_POINTER(0);
value = state->value;
}
unpack_res = uncompress((Bytef *) value, &dest_size, (Bytef *) VARDATA(data), VARSIZE(data));
if ( unpack_res != Z_OK ) {
ereport(ERROR, (errcode(ERRCODE_DATA_EXCEPTION), errmsg("can't decode value")));
}
count = dest_size / 4;
for(i = 0; i < count; i++) {
value[i] = ntohl(value[i]);
}
if ( !PG_ARGISNULL(0) ) {
merge_sets(1 << state->state[0], value + 2, state->state + 2);
}
PG_RETURN_POINTER(state);
}
Datum hll_merge(PG_FUNCTION_ARGS) {
bytea *state;
uint32_t *sdata;
bytea *value = PG_GETARG_BYTEA_P(1);
uint32_t *vdata = (uint32_t *) VARDATA(value);
if ( PG_ARGISNULL(0) ) {
PG_RETURN_BYTEA_P(value);
} else {
state = PG_GETARG_BYTEA_P(0);
sdata = (uint32_t *) VARDATA(state);
}
merge_sets(1 << sdata[0], vdata + 2, sdata + 2);
PG_RETURN_BYTEA_P(state);
}
