Method Write

lib/mdflib/mdflib/src/at4block.cpp:166–228

}

uint64_t At4Block::Write(std::streambuf& buffer) {
  const bool update = FilePosition() > 0;
  if (update) {
    return block_size_;
  }
  ByteArray data_buffer;
  try {
    path filename = u8path(filename_);
    if (!fs::exists(filename) && IsEmbedded()) {
      MDF_ERROR() << "Attachment File doesn't exist. File: " << filename_;
    }
    if (fs::exists(filename)) {
      if (const auto md5 = CreateMd5FileChecksum(filename_, md5_); md5) {
        flags_ |= At4Flags::kUsingMd5;
      }
      original_size_ = file_size(filename);
      if (IsEmbedded() && IsCompressed()) {
        if (const bool compress = Deflate(filename_, data_buffer); !compress) {
          MDF_ERROR() << "Compress failure. File: " << filename;
          return 0;
        }
      } else if (IsEmbedded()) {
        if (const auto read = FileToBuffer(filename_, data_buffer); !read) {
          MDF_ERROR() << "File to buffer failure. File: " << filename;
          return 0;
        }
      }
    }
  } catch (const std::exception& err) {
    MDF_ERROR() << "Attachment File error. Error: " << err.what()
                << ", File: " << filename_;
    return 0;
  }

  nof_bytes_ = data_buffer.size();

  block_type_ = "##AT";
  block_length_ = 24 + (4 * 8) + 2 + 2 + 4 + 16 + 8 + 8 + nof_bytes_;
  link_list_.resize(4, 0);

  WriteTx4(buffer, kIndexFilename, filename_);
  WriteTx4(buffer, kIndexType, file_type_);
  WriteMdComment(buffer, kIndexMd);

  uint64_t bytes = MdfBlock::Write(buffer);
  bytes += WriteNumber(buffer, flags_);
  bytes += WriteNumber(buffer, creator_index_);
  bytes += WriteBytes(buffer, 4);
  if (md5_.size() == 16) {
    bytes += WriteByte(buffer, md5_);
  } else {
    bytes += WriteBytes(buffer, 16);
  }
  bytes += WriteNumber(buffer, original_size_);
  bytes += WriteNumber(buffer, nof_bytes_);
  data_position_ = FilePosition();
  if (nof_bytes_ > 0) {
    bytes += WriteByte(buffer, data_buffer);