ArrowErrorCode ArrowIpcDecoderDecodeHeader()

in extensions/nanoarrow_ipc/src/nanoarrow/nanoarrow_ipc_decoder.c [1018:1077]
53 lines of code
12 McCabe index (conditional complexity)

ArrowErrorCode ArrowIpcDecoderDecodeHeader(struct ArrowIpcDecoder* decoder,
                                           struct ArrowBufferView data,
                                           struct ArrowError* error) {
  struct ArrowIpcDecoderPrivate* private_data =
      (struct ArrowIpcDecoderPrivate*)decoder->private_data;

  ArrowIpcDecoderResetHeaderInfo(decoder);
  NANOARROW_RETURN_NOT_OK(
      ArrowIpcDecoderCheckHeader(decoder, &data, &decoder->header_size_bytes, error));

  ns(Message_table_t) message = ns(Message_as_root(data.data.as_uint8));
  if (!message) {
    return EINVAL;
  }

  // Read some basic information from the message
  int32_t metadata_version = ns(Message_version(message));
  decoder->message_type = ns(Message_header_type(message));
  decoder->body_size_bytes = ns(Message_bodyLength(message));

  switch (decoder->metadata_version) {
    case ns(MetadataVersion_V5):
      break;
    case ns(MetadataVersion_V1):
    case ns(MetadataVersion_V2):
    case ns(MetadataVersion_V3):
    case ns(MetadataVersion_V4):
      ArrowErrorSet(error, "Expected metadata version V5 but found %s",
                    ns(MetadataVersion_name(decoder->metadata_version)));
      break;
    default:
      ArrowErrorSet(error, "Unexpected value for Message metadata version (%d)",
                    decoder->metadata_version);
      return EINVAL;
  }

  flatbuffers_generic_t message_header = ns(Message_header_get(message));
  switch (decoder->message_type) {
    case ns(MessageHeader_Schema):
      NANOARROW_RETURN_NOT_OK(
          ArrowIpcDecoderDecodeSchemaHeader(decoder, message_header, error));
      break;
    case ns(MessageHeader_RecordBatch):
      NANOARROW_RETURN_NOT_OK(
          ArrowIpcDecoderDecodeRecordBatchHeader(decoder, message_header, error));
      break;
    case ns(MessageHeader_DictionaryBatch):
    case ns(MessageHeader_Tensor):
    case ns(MessageHeader_SparseTensor):
      ArrowErrorSet(error, "Unsupported message type: '%s'",
                    ns(MessageHeader_type_name(decoder->message_type)));
      return ENOTSUP;
    default:
      ArrowErrorSet(error, "Unnown message type: %d", (int)(decoder->message_type));
      return EINVAL;
  }

  private_data->last_message = message_header;
  return NANOARROW_OK;
}