/*
* Find or create a hashtable entry for the tuple group containing the
* given tuple. The tuple must be the same type as the hashtable entries.
*
* If isnew is NULL, we do not create new entries; we return NULL if no
* match is found.
*
* If isnew isn't NULL, then a new entry is created if no existing entry
* matches. On return, *isnew is true if the entry is newly created,
* false if it existed already. ->additional_data in the new entry has
* been zeroed.
*/
TupleHashEntry
LookupTupleHashEntry(TupleHashTable hashtable, TupleTableSlot *slot,
bool *isnew)
{
TupleHashEntryData *entry;
MemoryContext oldContext;
bool found;
MinimalTuple key;
/* Need to run the hash functions in short-lived context */
oldContext = MemoryContextSwitchTo(hashtable->tempcxt);
/* set up data needed by hash and match functions */
hashtable->inputslot = slot;
hashtable->in_hash_funcs = hashtable->tab_hash_funcs;
hashtable->cur_eq_func = hashtable->tab_eq_func;
key = NULL; /* flag to reference inputslot */
if (isnew)
{
entry = tuplehash_insert(hashtable->hashtab, key, &found);
if (found)
{
/* found pre-existing entry */
*isnew = false;
}
else
{
/* created new entry */
*isnew = true;
/* zero caller data */
entry->additional = NULL;
MemoryContextSwitchTo(hashtable->tablecxt);
/* Copy the first tuple into the table context */
entry->firstTuple = ExecCopySlotMinimalTuple(slot);
}
}
else
{
entry = tuplehash_lookup(hashtable->hashtab, key);
}
MemoryContextSwitchTo(oldContext);
return entry;
}
/*
* Find or create a hashtable entry for the tuple group containing the
* given tuple. The tuple must be the same type as the hashtable entries.
*
* If isnew is NULL, we do not create new entries; we return NULL if no
* match is found.
*
* If isnew isn't NULL, then a new entry is created if no existing entry
* matches. On return, *isnew is true if the entry is newly created,
* false if it existed already. ->additional_data in the new entry has
* been zeroed.
*/
TupleHashEntry
LookupTupleHashEntry(TupleHashTable hashtable, TupleTableSlot *slot,
bool *isnew)
{
TupleHashEntryData *entry;
MemoryContext oldContext;
bool found;
MinimalTuple key;
/* If first time through, clone the input slot to make table slot */
if (hashtable->tableslot == NULL)
{
TupleDesc tupdesc;
oldContext = MemoryContextSwitchTo(hashtable->tablecxt);
/*
* We copy the input tuple descriptor just for safety --- we assume
* all input tuples will have equivalent descriptors.
*/
tupdesc = CreateTupleDescCopy(slot->tts_tupleDescriptor);
hashtable->tableslot = MakeSingleTupleTableSlot(tupdesc);
MemoryContextSwitchTo(oldContext);
}
/* Need to run the hash functions in short-lived context */
oldContext = MemoryContextSwitchTo(hashtable->tempcxt);
/* set up data needed by hash and match functions */
hashtable->inputslot = slot;
hashtable->in_hash_funcs = hashtable->tab_hash_funcs;
hashtable->cur_eq_funcs = hashtable->tab_eq_funcs;
key = NULL; /* flag to reference inputslot */
if (isnew)
{
entry = tuplehash_insert(hashtable->hashtab, key, &found);
if (found)
{
/* found pre-existing entry */
*isnew = false;
}
else
{
/* created new entry */
*isnew = true;
/* zero caller data */
entry->additional = NULL;
MemoryContextSwitchTo(hashtable->tablecxt);
/* Copy the first tuple into the table context */
entry->firstTuple = ExecCopySlotMinimalTuple(slot);
}
}
else
{
entry = tuplehash_lookup(hashtable->hashtab, key);
}
MemoryContextSwitchTo(oldContext);
return entry;
}
