How to upload by slice

[iewnfod]

I tried to upload a large file by slice and combine them after uploaded. After upload, there should be some functions like move to combine those segments, but I cannot find it.

Here is part of my code to upload.

Future<void> _uploadByChunk(Client davClient) async {
  final fileSize = getFileSize(localPath);
  final sliceCount = (fileSize / UPLOAD_SLICE_SIZE).ceil();

  final f = io.File(localPath);

  setStatus(.inProgress);

  for (int i = _uploadedSlice ?? 0; i < sliceCount; i++) {
    if (_cancelToken?.isCancelled == true) {
      print("Upload $id cancelled, stopping chunked upload");
      return;
    }
    final offset = i * UPLOAD_SLICE_SIZE;
    final currentChunkSize = (i == sliceCount - 1)
        ? fileSize - offset
        : UPLOAD_SLICE_SIZE;
    final sliceStream = await f
        .openRead(offset, offset + currentChunkSize)
        .toList();
    final sliceData = sliceStream.expand((x) => x).toList();

    await davClient.write(
      "$remotePath.part$i",
      Uint8List.fromList(sliceData),
      onProgress: (count, total) {
        final overallProgress = ((i * UPLOAD_SLICE_SIZE) + count) / fileSize;
        setProgress((overallProgress * fileSize).toInt(), fileSize);
      },
      cancelToken: _cancelToken,
    );

    _uploadedSlice = i + 1;
  }
}