Querying the cache

[whitequark]

Especially for larger applications, the cold startup time can be quite long. As a result people end up unsure whether the application is compiling or just hung. It would be nice if there was some way to check if I'm about to hit the cache, so that if I'm going to miss, I could print a message of some sort to stderr.

[alexcrichton]

Makes sense to me! I think with a feature like bytecodealliance/wasmtime#1779 we may be able to support this well where caching will be first-class at that point rather than hidden behind the scenes. In any case this'll need to be implemented upstream in Wasmtime first.

[whitequark]

Cool, looking forward to it. I'm very happy with wasmtime managing the caching for me though.

[alexcrichton]

With Module.deserialize and Module.serialize I think that this is "effectively done" in that it enables building the cache externally if this is desired. I don't think we're going to add more intrusive support for the built-in cache in Wasmtime itself given this feature as well.

[whitequark]

With Module.deserialize and Module.serialize I think that this is "effectively done" in that it enables building the cache externally if this is desired.

I've already done this so closing this is completely reasonable.