static int callback(rect_t r, void *data, void *arg)
{
callback_m_t x;
x = (callback_m_t) arg;
return Yap_ClauseListExtend(x->cl,data,x->pred);
}
/* index, called from absmi.c
*
* Returns:
* NULL (yap fallback) No usable indexing available
*
* Yap_FAILCODE() (fail) No result found
* Yap_CauseListToClause(cl) 1 solution found
* Yap_ClauseListCode(cl) 2+ solutions found
*/
yamop *
Yap_udi_search(PredEntry *p)
{
int r;
struct ClauseList clauselist;
UdiPArg parg;
UdiInfo info;
/* find our structure*/
HASH_FIND_UdiInfo(UdiControlBlocks,p,info);
if (!info || utarray_len(info->args) == 0)
return NULL;
if (utarray_len(info->args) == 1){ //simple case no intersection needed
struct si_callback_h c;
c.cl = Yap_ClauseListInit(&clauselist);
c.clauselist = info->clauselist;
c.pred = info->p;
if (!c.cl)
return NULL;
parg = (UdiPArg) utarray_eltptr(info->args,0);
r = parg->control->search(parg->idxstr, parg->arg, si_callback, (void *) &c);
Yap_ClauseListClose(c.cl);
if (r == -1) {
Yap_ClauseListDestroy(c.cl);
return NULL;
}
if (Yap_ClauseListCount(c.cl) == 0) {
Yap_ClauseListDestroy(c.cl);
return Yap_FAILCODE();
}
} else {//intersection needed using Judy1
#ifdef USE_JUDY
/*TODO: do more tests to this algorithm*/
int i;
Pvoid_t tmp = (Pvoid_t) NULL;
Pvoid_t result = (Pvoid_t) NULL;
Word_t count = 0L;
Word_t idx_r = 0L;
Word_t idx_tmp = 0L;
int rc = 0;
yamop **x;
/*
* I will start with the simplest approach
* for each index create a set and intersect it with the
* next
*
* In the future it could pay to sort according to index type
* to improve intersection part
*/
for (i = 0; i < utarray_len(info->args) ; i++) {
parg = (UdiPArg) utarray_eltptr(info->args,i);
r = parg->control->search(parg->idxstr, parg->arg, j1_callback, &tmp);
if (r == -1) /*this arg does not prune search*/
continue;
rc ++;
J1C(count, result, 0, -1);
if (r == 0) /* this arg gave 0 results -> FAIL*/
{
if (count > 0) // clear previous result if they exists
J1FA(count, result);
return Yap_FAILCODE();
}
if (count == 0) // first result_set
{
result = tmp;
tmp = (Pvoid_t) NULL;
}
else /*intersection*/
{
idx_tmp = 0L;
idx_r = 0L;
J1F(count, result, idx_r); //succeeds one time at least
assert(count > 0);
J1F(count, tmp, idx_tmp); //succeeds one time at least
assert(count > 0);
while (count)
{
while (idx_r < idx_tmp)
{
J1U(count, result, idx_r); //does not belong
J1N(count, result, idx_r); //next
if (! count) break; //end result set
}
if(idx_r == idx_tmp)
{
J1N(count, result, idx_r); //next
if (! count) break; //end result set
J1N(count, tmp, idx_tmp); //next tmp
//if (! count) break; //end tmp set will break while
}
else // (idx_r > idx_tmp)
{
idx_tmp = idx_r; // fast forward
J1F(count, tmp, idx_tmp); // first starting in idx_r
//if (! count) break; //end tmp set will break while
}
}
J1F(count, result, idx_r); // first starting in idx_r
//clear up the rest
while (idx_r > idx_tmp && count) //result has more setted values
{
J1U(count, result, idx_r); //does not belong
J1N(count, result, idx_r); //next
}
J1FA(count, tmp); //free tmp
}
}
if (rc == 0) /*no search performed*/
return NULL;
J1C(count, result, 0, -1);
if (count == 0) { /*result set empty -> FAIL */
J1FA(count, result);
return Yap_FAILCODE();
}
/*convert Juddy1 to clauselist*/
Yap_ClauseListInit(&clauselist);
idx_r = 0L;
J1F(count, result, idx_r);
while (count)
{
x = (yamop **) utarray_eltptr(info->clauselist, idx_r - 1);
Yap_ClauseListExtend(
&clauselist,
*x,
info->p);
J1N(count, result, idx_r);
}
J1FA(count,result);
fprintf(stderr,"J1 used space %ld bytes for %d clausules\n",
count, Yap_ClauseListCount(&clauselist));
Yap_ClauseListClose(&clauselist);
#else
fprintf(stderr,"Without libJudy only one argument indexed is allowed."
"Falling back to Yap Indexing\n");
return NULL; //NO Judy Available
#endif
}
if (Yap_ClauseListCount(&clauselist) == 1)
return Yap_ClauseListToClause(&clauselist);
return Yap_ClauseListCode(&clauselist);
}
