Method Convert

cpp/src/arrow/csv/converter.cc:611–636

  }

  Result<std::shared_ptr<Array>> Convert(const BlockParser& parser,
                                         int32_t col_index) override {
    // We use a fixed index width so that all column chunks get the same index type
    using BuilderType = Dictionary32Builder<T>;
    using value_type = typename ValueDecoderType::value_type;

    BuilderType builder(value_type_, pool_);
    RETURN_NOT_OK(PresizeBuilder(parser, &builder));

    auto visit = [&](const uint8_t* data, uint32_t size, bool quoted) -> Status {
      if (decoder_.IsNull(data, size, quoted /* quoted */)) {
        return builder.AppendNull();
      }
      if (ARROW_PREDICT_FALSE(builder.dictionary_length() > max_cardinality_)) {
        return Status::IndexError("Dictionary length exceeded max cardinality");
      }
      value_type value{};
      RETURN_NOT_OK(decoder_.Decode(data, size, quoted, &value));
      return builder.Append(value);
    };
    RETURN_NOT_OK(parser.VisitColumn(col_index, visit));

    std::shared_ptr<Array> res;
    RETURN_NOT_OK(builder.Finish(&res));
    return res;
  }

  void SetMaxCardinality(int32_t max_length) override { max_cardinality_ = max_length; }