Add cache mechanism to node

[kandy]

No description provided.

[andrewtvuong]

Hi @kandy just curious how does cache help, can you give a usecase? Wondering because probably won't see the same image twice or am I mistaken

[kandy]

I use Tagger in img2img workflows and I often modified parameters at end of workflow, so I don't want that tags is recalculated for the same image and workflow start from start

[jkrauss82]

I think this is a valuable PR as currently often tags are re-calculated for the same images (not always, haven't been able to figure why).

I have worked on this node yesterday and figured some other things:

• moving the new parameter "cache" to property "optional" of the node's parameters will help to not break legacy workflows not having the new parameter in their JSON, yet
• I would recommend to only calculate the hash if cache is True.
• what about image batches? Does it work for them as well like it is currently implemented?

[OsmosisD]

Still waiting for this. It causes a lot of wasted overhead when re-running a workflow with other parameters changed, especially when using a larger model such as wd-eva02-large-tagger-v3.
As for recalculation of tags, it seems to be on some sort of timeout (maybe inadvertent?). i.e. if I wait more than a few minutes between each run (or if each run takes longer than that), it recalculates it again, even though it doesn't need to.

Also possibly relevant, if switching back and forth between open workflows, the output from WD14 Tagger vanishes from being displayed. Although this largely seems to be a bug in ComfyUI itself, not all nodes suffer from this problem.

[Dwanvea]

Please merge this

[EricBCoding]

As a heads up, the cache mechanism does not work when the node is in a subgraph. It will re-run every time, even if no inputs have changed.