absl::Status DecodeTopLevelFeatures()

in tfx_bsl/cc/coders/example_decoder.cc [594:649]
49 lines of code
13 McCabe index (conditional complexity)

absl::Status DecodeTopLevelFeatures(
    const google::protobuf::Map<std::string, tensorflow::Feature>& features,
    absl::flat_hash_set<std::string>& all_features_seen,
    const int num_examples_already_processed,
    absl::flat_hash_map<std::string, std::unique_ptr<FeatureDecoder>>&
        feature_decoders) {
  for (const auto& p : features) {
    const std::string& feature_name = p.first;
    const tensorflow::Feature& feature = p.second;
    const auto it = feature_decoders.find(feature_name);
    FeatureDecoder* feature_decoder = nullptr;
    if (it != feature_decoders.end()) {
      feature_decoder = it->second.get();
    } else {
      all_features_seen.insert(feature_name);
      switch (feature.kind_case()) {
        case tensorflow::Feature::kInt64List:
          feature_decoder = IntDecoder::Make();
          break;
        case tensorflow::Feature::kFloatList:
          feature_decoder = FloatDecoder::Make();
          break;
        case tensorflow::Feature::kBytesList:
          feature_decoder = BytesDecoder::Make();
          break;
        case tensorflow::Feature::KIND_NOT_SET:
          // Leave feature_decoder as nullptr.
          break;
      }
      if (feature_decoder) {
        // Handle the situation in which we see a feature for the first time
        // after already having processed some examples. In that case, append
        // a null for each example that has already been processed (in which
        // this feature was not seen), excluding the current example.
        for (int j = 0; j < num_examples_already_processed; ++j) {
          TFX_BSL_RETURN_IF_ERROR(feature_decoder->AppendNull());
        }
        feature_decoders[feature_name] = absl::WrapUnique(feature_decoder);
      }
    }
    if (feature_decoder) {
      absl::Status status = feature_decoder->DecodeFeature(feature);
      if (!status.ok()) {
        return absl::Status(status.code(),
                            absl::StrCat(status.message(), " for feature \"",
                                         feature_name, "\""));
      }
    }
  }

  for (const auto& p : feature_decoders) {
    TFX_BSL_RETURN_IF_ERROR(p.second->FinishFeature());
  }

  return absl::OkStatus();
}