Reduce complexity in determining the cycle

[JustinPrivitera]

The cycle comes from different places:

For the viewer it comes from the database. For the time slider in the main window it comes from the filename. Why do we do it this way? This leads to issues like #20080, but also can lead to issues whenever the filename cycle doesn't match the database cycle.

If you add print statements to the Silo Database everywhere that cycle comes up you will see that the plugin is being asked for the cycle in different ways.

[markcmiller86]

The stuff related to handling of cycles and times from databases is massively complex and involves optimizations for whether a file is actually to be opened by a plugin or just the string of the filename itself is processed. So, the GUI does as little work as possible to get cycle information and will therefore always guess from a filename. The value displayed in the viewer is always better in that it is derived most frequently from data actually stored in the file. Why? Because by the time something is being displayed in the viewer, the file has to have already been opened.

Next, we tend to gather cycles (and times when/if available) for all states when we open any state. That means opening and getting data from each and every file in a time series (expensive) or opening only the current state (wherever the user decided to open) and guessing from a filename for everything else.

[JustinPrivitera]

I see, that makes sense. Thanks for the detailed answer. Do we want to change anything or should we just close this?

[markcmiller86]

Do we want to change anything or should we just close this?

I think the logic for all this could be substantially simplified and if that is what this ticket is about, I think it's worth keeping open. There may be other issues related to this too. The complexity I mentioned is partly my own doing and partly other developer's doing. But, I also think it is unnecessary.

[JustinPrivitera]

Ok. Let's leave it open then and have the action item be to reduce complexity for determining the cycle.

[JustinPrivitera]

VisIt tries hard to not open files unless it is making plots from those files, leading to confusion like what was shown above. Cycle optimizations should be examined and simplified, if possible.