Method partition

bolt/exec/HashPartitionFunction.cpp:73–107

}

std::optional<uint32_t> HashPartitionFunction::partition(
    const RowVector& input,
    std::vector<uint32_t>& partitions) {
  if (hashers_.empty()) {
    return 0u;
  }

  const auto size = input.size();
  rows_.resize(size);
  rows_.setAll();

  hashes_.resize(size);
  for (auto i = 0; i < hashers_.size(); ++i) {
    auto& hasher = hashers_[i];
    if (hasher->channel() != kConstantChannel) {
      hashers_[i]->decode(*input.childAt(hasher->channel()), rows_);
      hashers_[i]->hash(rows_, i > 0, hashes_);
    } else {
      hashers_[i]->hashPrecomputed(rows_, i > 0, hashes_);
    }
  }

  partitions.resize(size);
  if (hashBitRange_.has_value()) {
    for (auto i = 0; i < size; ++i) {
      partitions[i] = hashBitRange_->partition(hashes_[i]);
    }
  } else {
    for (auto i = 0; i < size; ++i) {
      partitions[i] = hashes_[i] % numPartitions_;
    }
  }

  return std::nullopt;
}

std::unique_ptr<core::PartitionFunction> HashPartitionFunctionSpec::create(
    int numPartitions) const {