Function WriteFeatherV1

cpp/src/arrow/ipc/feather.cc:671–705

}

Status WriteFeatherV1(const Table& table, io::OutputStream* dst) {
  // Preamble
  int64_t bytes_written;
  RETURN_NOT_OK(WritePadded(dst, reinterpret_cast<const uint8_t*>(kFeatherV1MagicBytes),
                            strlen(kFeatherV1MagicBytes), &bytes_written));

  // Write columns
  flatbuffers::FlatBufferBuilder fbb;
  std::vector<flatbuffers::Offset<fbs::Column>> fb_columns;
  for (int i = 0; i < table.num_columns(); ++i) {
    ColumnMetadata col;
    RETURN_NOT_OK(WriteColumnV1(*table.column(i), dst, &col));
    auto fb_column = fbs::CreateColumn(
        fbb, fbb.CreateString(table.field(i)->name()), GetPrimitiveArray(fbb, col.values),
        ToFlatbufferEnum(col.meta_type), col.WriteMetadata(fbb),
        /*user_metadata=*/0);
    fb_columns.push_back(fb_column);
  }

  // Finalize file footer
  auto root = fbs::CreateCTable(fbb, /*description=*/0, table.num_rows(),
                                fbb.CreateVector(fb_columns), kFeatherV1Version,
                                /*metadata=*/0);
  fbb.Finish(root);
  auto buffer = std::make_shared<Buffer>(fbb.GetBufferPointer(),
                                         static_cast<int64_t>(fbb.GetSize()));

  // Writer metadata
  RETURN_NOT_OK(WritePadded(dst, buffer->data(), buffer->size(), &bytes_written));
  uint32_t metadata_size = static_cast<uint32_t>(bytes_written);

  // Footer: metadata length, magic bytes
  RETURN_NOT_OK(dst->Write(&metadata_size, sizeof(uint32_t)));
  return dst->Write(kFeatherV1MagicBytes, strlen(kFeatherV1MagicBytes));
}

// ----------------------------------------------------------------------
// Reader V2