Method GetColumnIndex

cpp/src/parquet/page_index.cc:232–270

Read column index of a column chunk.

  /// Read column index of a column chunk.
  std::shared_ptr<ColumnIndex> GetColumnIndex(int32_t i) override {
    if (i < 0 || i >= row_group_metadata_->num_columns()) {
      throw ParquetException("Invalid column index at column ordinal ", i);
    }

    auto col_chunk = row_group_metadata_->ColumnChunk(i);
    auto column_index_location = col_chunk->GetColumnIndexLocation();
    if (!column_index_location.has_value()) {
      return nullptr;
    }

    CheckReadRangeOrThrow(*column_index_location, index_read_range_.column_index,
                          row_group_ordinal_);

    if (column_index_buffer_ == nullptr) {
      column_index_buffer_ =
          ReadIndexBuffer(index_read_range_.column_index->offset,
                          index_read_range_.column_index->length, "ColumnIndex");
    }

    int64_t buffer_offset =
        column_index_location->offset - index_read_range_.column_index->offset;
    // ColumnIndex::Make() requires the type of serialized thrift message to be
    // uint32_t
    uint32_t length = static_cast<uint32_t>(column_index_location->length);
    auto descr = row_group_metadata_->schema()->Column(i);

    // Get decryptor of column index if encrypted.
    std::unique_ptr<Decryptor> decryptor =
        InternalFileDecryptor::GetColumnMetaDecryptorFactory(
            file_decryptor_, col_chunk->crypto_metadata().get())();
    if (decryptor != nullptr) {
      UpdateDecryptor(decryptor.get(), row_group_ordinal_, /*column_ordinal=*/i,
                      encryption::kColumnIndex);
    }

    return ColumnIndex::Make(*descr, column_index_buffer_->data() + buffer_offset, length,
                             properties_, decryptor.get());
  }

  /// Read offset index of a column chunk.
  std::shared_ptr<OffsetIndex> GetOffsetIndex(int32_t i) override {