/*
* OperatorGet
*
* finds an operator given an exact specification (name, namespace,
* left and right type IDs).
*
* *defined is set TRUE if defined (not a shell)
*/
static Oid
OperatorGet(const char *operatorName,
Oid operatorNamespace,
Oid leftObjectId,
Oid rightObjectId,
bool *defined)
{
HeapTuple tup;
Oid operatorObjectId;
tup = SearchSysCache4(OPERNAMENSP,
PointerGetDatum(operatorName),
ObjectIdGetDatum(leftObjectId),
ObjectIdGetDatum(rightObjectId),
ObjectIdGetDatum(operatorNamespace));
if (HeapTupleIsValid(tup))
{
RegProcedure oprcode = ((Form_pg_operator) GETSTRUCT(tup))->oprcode;
operatorObjectId = HeapTupleGetOid(tup);
*defined = RegProcedureIsValid(oprcode);
ReleaseSysCache(tup);
}
else
{
operatorObjectId = InvalidOid;
*defined = false;
}
return operatorObjectId;
}
/*
* Cache and return the procedure for the given strategy.
*/
FmgrInfo *
minmax_get_strategy_procinfo(BrinDesc *bdesc, uint16 attno, Oid subtype,
uint16 strategynum)
{
MinmaxOpaque *opaque;
Assert(strategynum >= 1 &&
strategynum <= BTMaxStrategyNumber);
opaque = (MinmaxOpaque *) bdesc->bd_info[attno - 1]->oi_opaque;
/*
* We cache the procedures for the previous subtype in the opaque struct,
* to avoid repetitive syscache lookups. If the subtype changed,
* invalidate all the cached entries.
*/
if (opaque->cached_subtype != subtype)
{
uint16 i;
for (i = 1; i <= BTMaxStrategyNumber; i++)
opaque->strategy_procinfos[i - 1].fn_oid = InvalidOid;
opaque->cached_subtype = subtype;
}
if (opaque->strategy_procinfos[strategynum - 1].fn_oid == InvalidOid)
{
Form_pg_attribute attr;
HeapTuple tuple;
Oid opfamily,
oprid;
bool isNull;
opfamily = bdesc->bd_index->rd_opfamily[attno - 1];
attr = bdesc->bd_tupdesc->attrs[attno - 1];
tuple = SearchSysCache4(AMOPSTRATEGY, ObjectIdGetDatum(opfamily),
ObjectIdGetDatum(attr->atttypid),
ObjectIdGetDatum(subtype),
Int16GetDatum(strategynum));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
strategynum, attr->atttypid, subtype, opfamily);
oprid = DatumGetObjectId(SysCacheGetAttr(AMOPSTRATEGY, tuple,
Anum_pg_amop_amopopr, &isNull));
ReleaseSysCache(tuple);
Assert(!isNull && RegProcedureIsValid(oprid));
fmgr_info_cxt(get_opcode(oprid),
&opaque->strategy_procinfos[strategynum - 1],
bdesc->bd_context);
}
return &opaque->strategy_procinfos[strategynum - 1];
}