Feature request: to add a pause and restart, and a ddrescue alike map file

[jyzhang918]

This program works. It is great. However, the software decryption is very slow. On my computer it take about an hour to decrypt 1GB data. For a 1TB drive, that will take about 1000hrs or about 50 days.

The software does not have a pause/stop and restart feature, that means to run a computer non-stop for 50 days. A lot can happen in a 50 days period, without a restart from where it left off, that means if anything happens, it has to restart the 50 day circle again from the very beginning.

Beyond a multi-thread feature to increase the decryption speed, if we can at least implement a pause/stop, restart from where it last stopped would significantly improve the usability of the program. If there is a map file feature like ddrescue, it will become a powerful tool.

Can this feature be implement? Thank you very much for making this software available. It is a great tool.