13.aria2_download_dir VS. aria2_candidate_dirs

What is the difference between `aria2_download_dir` and `aria2_candidate_dirs` parameters and how to set them correctly?

In the latest v2.2.0-rc1,

• aria2_download_dir is the only path where CAR files can be downloaded

• aria2_candidate_dirs is the path where CAR files can pre-exist, and files downloaded through Swan Provider will not be saved under this path

If the CAR files of the storage provider's deals are all downloaded through Swan Provider, aria2_download_dirand aria2_candidate_dirs can be set to the same.

If the CAR files of storage providers' deals are stored in local paths before the deals are sent, these paths can be configured in aria2_candidate_dirs, and multiple directories are supported.

After the deals are sent, Swan Provider will give priority to matching the CAR files corresponding to the deals from the aria2_candidate_dirs directory.

Note: To make full use of the data reading performance of a single path, Swan Provider only supports one file to be imported in one single path.