Function ARROW_ASSIGN_OR_RAISE

cpp/src/arrow/flight/serialization_internal.cc:704–763

  // Allocate and initialize buffers
  arrow::BufferVector buffers;
  ARROW_ASSIGN_OR_RAISE(auto header_buf, arrow::AllocateBuffer(header_size));

  // Force the header_stream to be destructed, which actually flushes
  // the data into the slice.
  {
    ArrayOutputStream header_writer(const_cast<uint8_t*>(header_buf->mutable_data()),
                                    static_cast<int>(header_size));
    CodedOutputStream header_stream(&header_writer);

    // Write descriptor
    if (msg.descriptor != nullptr) {
      WireFormatLite::WriteTag(pb::FlightData::kFlightDescriptorFieldNumber,
                               WireFormatLite::WIRETYPE_LENGTH_DELIMITED, &header_stream);
      header_stream.WriteVarint32(descriptor_size);
      header_stream.WriteRawMaybeAliased(msg.descriptor->data(),
                                         static_cast<int>(msg.descriptor->size()));
    }

    // Write header
    if (has_ipc) {
      WireFormatLite::WriteTag(pb::FlightData::kDataHeaderFieldNumber,
                               WireFormatLite::WIRETYPE_LENGTH_DELIMITED, &header_stream);
      header_stream.WriteVarint32(metadata_size);
      header_stream.WriteRawMaybeAliased(ipc_msg.metadata->data(),
                                         static_cast<int>(ipc_msg.metadata->size()));
    }

    // Write app metadata
    if (app_metadata_size > 0) {
      WireFormatLite::WriteTag(pb::FlightData::kAppMetadataFieldNumber,
                               WireFormatLite::WIRETYPE_LENGTH_DELIMITED, &header_stream);
      header_stream.WriteVarint32(app_metadata_size);
      header_stream.WriteRawMaybeAliased(msg.app_metadata->data(),
                                         static_cast<int>(msg.app_metadata->size()));
    }

    if (has_body) {
      // Write body tag
      WireFormatLite::WriteTag(pb::FlightData::kDataBodyFieldNumber,
                               WireFormatLite::WIRETYPE_LENGTH_DELIMITED, &header_stream);
      header_stream.WriteVarint32(static_cast<uint32_t>(body_size));

      // Enqueue body buffers for writing, without copying
      for (const auto& buffer : ipc_msg.body_buffers) {
        // Buffer may be null when the row length is zero, or when all
        // entries are invalid.
        if (!buffer || buffer->size() == 0) continue;
        buffers.push_back(buffer);

        // Write padding if not multiple of 8
        const auto remainder = static_cast<int>(
            bit_util::RoundUpToMultipleOf8(buffer->size()) - buffer->size());
        if (remainder) {
          buffers.push_back(std::make_shared<arrow::Buffer>(kPaddingBytes, remainder));
        }
      }
    }