Resume Run Functionality

[Modularius]

Summary of changes

Added behaviour for the Nexus Writer to resume a run if it was interrupted by the component going down.

• A file with extension ".partial_run" is added to the local path when a run_start is received. This file is removed when the nexus file is transferred to the archive (signalling a successful run).
• When the nexus writer starts, any ".partial_run" ".nxs" files in the local path are read and runs re-created (as .partial_run .nxs files indicate that a previous instance of nexus writer had failed).

Instruction for review/testing

General code review.

Tool was tested with simulated data.

[DanNixon]

Is there a reason the NeXus file itself cannot be used as the source of information for a restarted run if the currently written to file uses the .nxs.tmp extension? This may be cleaner than writing a separate file.

[Modularius]

I considered that, but thought it would couple the design of the file format with this functionality. I'd rather avoid that if possible.

[DanNixon]

I considered that, but thought it would couple the design of the file format with this functionality. I'd rather avoid that if possible.

But all the information is already recorded in the data file (and can be assumed to always be there, as it is all pretty basic information). I can't see why just using that is not the most straightforward.

[Modularius]

On second thoughts, you are right that this is the cleanest way to do it.