If you are using the checkpointLocationoption you can read all the files that were processed by reading the rocksDB logs. Some example code to achieve that, note that you need to point to the path on the checkpoint location that you want to retrieve the loaded files list.
from glob import glob
import codecs
directory = "<YOUR_PATH_GOES_HERE>/sources/*/rocksdb/logs/"
for file in glob(f"{directory}/*.log"):
with codecs.open(file, encoding='utf-8', errors='ignore') as f:
f = f.readlines()
print(f)