/*
* Add bits of given value to the signature.
*/
void
signValue(BloomState *state, BloomSignatureWord *sign, Datum value, int attno)
{
uint32 hashVal;
int nBit,
j;
/*
* init generator with "column's" number to get "hashed" seed for new
* value. We don't want to map the same numbers from different columns
* into the same bits!
*/
mySrand(attno);
/*
* Init hash sequence to map our value into bits. the same values in
* different columns will be mapped into different bits because of step
* above
*/
hashVal = DatumGetInt32(FunctionCall1Coll(&state->hashFn[attno], state->collations[attno], value));
mySrand(hashVal ^ myRand());
for (j = 0; j < state->opts.bitSize[attno]; j++)
{
/* prevent multiple evaluation in SETBIT macro */
nBit = myRand() % (state->opts.bloomLength * SIGNWORDBITS);
SETBIT(sign, nBit);
}
}
/*
* initialize a GiST entry with a decompressed version of key
*/
void
gistdentryinit(GISTSTATE *giststate, int nkey, GISTENTRY *e,
Datum k, Relation r, Page pg, OffsetNumber o,
bool l, bool isNull)
{
if (!isNull)
{
GISTENTRY *dep;
gistentryinit(*e, k, r, pg, o, l);
/* there may not be a decompress function in opclass */
if (!OidIsValid(giststate->decompressFn[nkey].fn_oid))
return;
dep = (GISTENTRY *)
DatumGetPointer(FunctionCall1Coll(&giststate->decompressFn[nkey],
giststate->supportCollation[nkey],
PointerGetDatum(e)));
/* decompressFn may just return the given pointer */
if (dep != e)
gistentryinit(*e, dep->key, dep->rel, dep->page, dep->offset,
dep->leafkey);
}
else
gistentryinit(*e, (Datum) 0, r, pg, o, l);
}
/*
* Hash function for elements.
*
* We use the element type's default hash opclass, and the default collation
* if the type is collation-sensitive.
*/
static uint32
element_hash(const void *key, Size keysize)
{
Datum d = *((const Datum *) key);
Datum h;
h = FunctionCall1Coll(array_extra_data->hash, DEFAULT_COLLATION_OID, d);
return DatumGetUInt32(h);
}
/*
* _hash_datum2hashkey -- given a Datum, call the index's hash procedure
*
* The Datum is assumed to be of the index's column type, so we can use the
* "primary" hash procedure that's tracked for us by the generic index code.
*/
uint32
_hash_datum2hashkey(Relation rel, Datum key)
{
FmgrInfo *procinfo;
Oid collation;
/* XXX assumes index has only one attribute */
procinfo = index_getprocinfo(rel, 1, HASHPROC);
collation = rel->rd_indcollation[0];
return DatumGetUInt32(FunctionCall1Coll(procinfo, collation, key));
}
/*
* initialize a GiST entry with fetched value in key field
*/
static Datum
gistFetchAtt(GISTSTATE *giststate, int nkey, Datum k, Relation r)
{
GISTENTRY fentry;
GISTENTRY *fep;
gistentryinit(fentry, k, r, NULL, (OffsetNumber) 0, false);
fep = (GISTENTRY *)
DatumGetPointer(FunctionCall1Coll(&giststate->fetchFn[nkey],
giststate->supportCollation[nkey],
PointerGetDatum(&fentry)));
/* fetchFn set 'key', return it to the caller */
return fep->key;
}
IndexTuple
gistFormTuple(GISTSTATE *giststate, Relation r,
Datum attdata[], bool isnull[], bool isleaf)
{
Datum compatt[INDEX_MAX_KEYS];
int i;
IndexTuple res;
/*
* Call the compress method on each attribute.
*/
for (i = 0; i < r->rd_att->natts; i++)
{
if (isnull[i])
compatt[i] = (Datum) 0;
else
{
GISTENTRY centry;
GISTENTRY *cep;
gistentryinit(centry, attdata[i], r, NULL, (OffsetNumber) 0,
isleaf);
/* there may not be a compress function in opclass */
if (OidIsValid(giststate->compressFn[i].fn_oid))
cep = (GISTENTRY *)
DatumGetPointer(FunctionCall1Coll(&giststate->compressFn[i],
giststate->supportCollation[i],
PointerGetDatum(¢ry)));
else
cep = ¢ry;
compatt[i] = cep->key;
}
}
res = index_form_tuple(giststate->tupdesc, compatt, isnull);
/*
* The offset number on tuples on internal pages is unused. For historical
* reasons, it is set to 0xffff.
*/
ItemPointerSetOffsetNumber(&(res->t_tid), 0xffff);
return res;
}
/*
* initialize a GiST entry with a compressed version of key
*/
void
gistcentryinit(GISTSTATE *giststate, int nkey,
GISTENTRY *e, Datum k, Relation r,
Page pg, OffsetNumber o, bool l, bool isNull)
{
if (!isNull)
{
GISTENTRY *cep;
gistentryinit(*e, k, r, pg, o, l);
cep = (GISTENTRY *)
DatumGetPointer(FunctionCall1Coll(&giststate->compressFn[nkey],
giststate->supportCollation[nkey],
PointerGetDatum(e)));
/* compressFn may just return the given pointer */
if (cep != e)
gistentryinit(*e, cep->key, cep->rel, cep->page, cep->offset,
cep->leafkey);
}
else
gistentryinit(*e, (Datum) 0, r, pg, o, l);
}
