Method makeEncodingPreservedCopy

bolt/vector/fuzzer/VectorFuzzer.cpp:1558–1614

}

VectorPtr VectorLoaderWrap::makeEncodingPreservedCopy(
    SelectivityVector& rows,
    vector_size_t vectorSize) {
  DecodedVector decoded;
  decoded.decode(*vector_, rows, false);

  if (decoded.isConstantMapping() || decoded.isIdentityMapping()) {
    VectorPtr result;
    BaseVector::ensureWritable(rows, vector_->type(), vector_->pool(), result);
    result->resize(vectorSize);
    result->copy(vector_.get(), rows, nullptr, false);
    return result;
  }

  SelectivityVector baseRows;
  auto baseVector = decoded.base();

  baseRows.resize(baseVector->size(), false);
  rows.applyToSelected([&](auto row) {
    if (!decoded.isNullAt(row)) {
      baseRows.setValid(decoded.index(row), true);
    }
  });
  baseRows.updateBounds();

  VectorPtr baseResult;
  BaseVector::ensureWritable(
      baseRows, baseVector->type(), vector_->pool(), baseResult);
  baseResult->copy(baseVector, baseRows, nullptr, false);

  BufferPtr indices = allocateIndices(vectorSize, vector_->pool());
  auto rawIndices = indices->asMutable<vector_size_t>();
  auto decodedIndices = decoded.indices();
  rows.applyToSelected(
      [&](auto row) { rawIndices[row] = decodedIndices[row]; });

  BufferPtr nulls = nullptr;
  if (decoded.nulls(&rows) || vectorSize > rows.end()) {
    // We fill [rows.end(), vectorSize) with nulls then copy nulls for selected
    // baseRows.
    nulls = allocateNulls(vectorSize, vector_->pool(), bits::kNull);
    if (baseRows.hasSelections()) {
      if (decoded.nulls(&rows)) {
        std::memcpy(
            nulls->asMutable<uint64_t>(),
            decoded.nulls(&rows),
            bits::nbytes(rows.end()));
      } else {
        bits::fillBits(
            nulls->asMutable<uint64_t>(), 0, rows.end(), bits::kNotNull);
      }
    }
  }

  return BaseVector::wrapInDictionary(
      std::move(nulls), std::move(indices), vectorSize, baseResult);
}