Function TupleHashTableHash

src/backend/executor/execGrouping.c:348–365

* Compute the hash value for a tuple */

 * Compute the hash value for a tuple
 */
uint32
TupleHashTableHash(TupleHashTable hashtable, TupleTableSlot *slot)
{
	MemoryContext oldContext;
	uint32		hash;

	hashtable->inputslot = slot;
	hashtable->in_hash_funcs = hashtable->tab_hash_funcs;

	/* Need to run the hash functions in short-lived context */
	oldContext = MemoryContextSwitchTo(hashtable->tempcxt);

	hash = TupleHashTableHash_internal(hashtable->hashtab, NULL);

	MemoryContextSwitchTo(oldContext);

	return hash;
}

/*
 * A variant of LookupTupleHashEntry for callers that have already computed