Option to keep or replace generated moment images when a new request is made (backend)

[pford]

Split from #1176 , now for PV images only. This is for moment images only.

[pford]

Created protobuf branch moment_keep_option

[pford]

@kswang1029 each moment can be requested individually and has a unique name, i.e. "image.moment.average", "image.moment.integrated", etc. We can append an index to these names, as in PV image, but are the frontend/backend required to keep track of which moments have been generated? Or is it indexed by generation?

For example, the user requests mom -1 keep=false ("image.average"), then mom 0 keep=true ("image.integrated" or "image.integrated1"?), then mom -1, 0, 1 keep=true ("image.averageX", "image.integratedX" , "image.weighted_coordX" - what is X for each?).

[pford]

I just pushed a branch for an initial implementation, where the index is incremented each time keep=true for all generated moment images, but this can be changed.

So in my previous example (assuming I got the names right for the moment numbers!) you would get:

• mom -1 keep=false: image.average
• mom 0 keep=true: image.integrated1
• mom -1, 0, 1 keep=true: image.average2, image.integrated2 , image.weighted_coord2

When keep=false, there is no index appended. When keep=true, the last-used index is incremented for the new images. If this is acceptable, I will open a draft PR.

[kswang1029]

I just pushed a branch for an initial implementation, where the index is incremented each time keep=true for all generated moment images, but this can be changed.

So in my previous example (assuming I got the names right for the moment numbers!) you would get:

• mom -1 keep=false: image.average
• mom 0 keep=true: image.integrated1
• mom -1, 0, 1 keep=true: image.average2, image.integrated2 , image.weighted_coord2

When keep=false, there is no index appended. When keep=true, the last-used index is incremented for the new images. If this is acceptable, I will open a draft PR.

Yes this sounds good.