Introduced in #11695 .
The tryResizeHashTables function gets stuck on the last non-empty slot
while iterating through dictionaries. It does not restart from the
beginning. The reason for this issue is a problem with the usage of
dbIteratorNextDict:
/* Returns next dictionary from the iterator, or NULL if iteration is complete. */
dict *dbIteratorNextDict(dbIterator *dbit) {
if (dbit->next_slot == -1) return NULL;
dbit->slot = dbit->next_slot;
dbit->next_slot = dbGetNextNonEmptySlot(dbit->db, dbit->slot, dbit->keyType);
return dbGetDictFromIterator(dbit);
}
When iterating to the last non-empty slot, next_slot is set to -1,
causing it to loop indefinitely on that slot. We need to modify the code
to ensure that after iterating to the last non-empty slot, it returns to
the first non-empty slot.
BTW, function tryResizeHashTables is actually iterating over slots
that have keys. However, in its implementation, it leverages the
dbIterator (which is a key iterator) to obtain slot and dictionary
information. While this approach works fine, but it is not very
intuitive. This PR also improves readability by changing the iteration
to directly iterate over slots, thereby enhancing clarity.
a1c5171c1d