Method prepareForGroupProbe

bolt/exec/HashTable.cpp:2303–2349

}

void BaseHashTable::prepareForGroupProbe(
    HashLookup& lookup,
    const RowVectorPtr& input,
    SelectivityVector& rows,
    bool ignoreNullKeys,
    int8_t spillInputStartPartitionBit) {
  checkHashBitsOverlap(spillInputStartPartitionBit);
  auto& hashers = lookup.hashers;

  for (auto& hasher : hashers) {
    auto key = input->childAt(hasher->channel())->loadedVector();
    hasher->decode(*key, rows);
  }

  if (ignoreNullKeys) {
    // A null in any of the keys disables the row.
    deselectRowsWithNulls(hashers, rows);
  }

  lookup.reset(rows.end());

  bool rehash = false;
  const auto mode = hashMode();
  for (auto i = 0; i < hashers.size(); ++i) {
    auto& hasher = hashers[i];
    if (mode != BaseHashTable::HashMode::kHash) {
      if (!hasher->computeValueIds(rows, lookup.hashes)) {
        rehash = true;
      }
    } else {
      hasher->hash(rows, i > 0, lookup.hashes);
    }
  }

  if (rehash || capacity() == 0) {
    if (mode != BaseHashTable::HashMode::kHash) {
      decideHashMode(input->size());
      // Do not forward 'ignoreNullKeys' to avoid redundant evaluation of
      // deselectRowsWithNulls.
      prepareForGroupProbe(
          lookup, input, rows, false, spillInputStartPartitionBit);
      return;
    }
  }

  populateLookupRows(rows, lookup.rows);
}

void BaseHashTable::prepareForJoinProbe(
    HashLookup& lookup,