Function readDictionaryVector

bolt/serializers/PrestoSerializer.cpp:502–537

}

void readDictionaryVector(
    ByteInputStream* source,
    const TypePtr& type,
    bolt::memory::MemoryPool* pool,
    VectorPtr& result,
    vector_size_t resultOffset,
    bool useLosslessTimestamp) {
  const auto size = source->read<int32_t>();

  std::vector<TypePtr> childTypes = {type};
  std::vector<VectorPtr> children{BaseVector::create(type, 0, pool)};
  readColumns(source, pool, childTypes, children, 0, useLosslessTimestamp);

  // Read indices.
  BufferPtr indices = allocateIndices(size, pool);
  source->readBytes(indices->asMutable<char>(), size * sizeof(int32_t));

  // Skip 3 * 8 bytes of 'instance id'. Bolt doesn't use 'instance id' for
  // dictionary vectors.
  source->skip(24);

  auto dictionaryVector =
      BaseVector::wrapInDictionary(nullptr, indices, size, children[0]);
  if (resultOffset == 0) {
    result = std::move(dictionaryVector);
  } else {
    result->resize(resultOffset + size);

    SelectivityVector rows(resultOffset + size, false);
    rows.setValidRange(resultOffset, resultOffset + size, true);
    rows.updateBounds();

    BaseVector::ensureWritable(rows, type, pool, result);
    result->copy(dictionaryVector.get(), resultOffset, 0, size);
  }
}

void readArrayVector(
    ByteInputStream* source,