Make new Weight struct #[codec(compact)]

[shawntabrizi]

The fields in the new weight struct should be #[codec(compact)], which will involve a storage migration for any places where weight is stored.

Makes sense to do this the same time we need to do a storage migration for the second field of Weight.

[bkchr]

You should be able to implement scale_codec::CompactAs and then you should not need any migration.

[shawntabrizi]

So the implementation will try compact decode, and if it fails, try u64 decode?

[bkchr]

No, then you can write #[compact] as before. So, nothing would change in the declaration of dispatchables. However, weight would still be stored by default without compaction.

[shawntabrizi]

okay, but actually i would like to also make the values compact by default in the future

[shawntabrizi]

@bkchr here is me using compact as for now, but should make it actually compact in the future as mentioned in this issue:

b6eb595

[bkchr]

@bkchr here is me using compact as for now, but should make it actually compact in the future as mentioned in this issue:

b6eb595

Okay :P Yeah, when we switch to the two dimensional we will need some migrations anyway.

[KiChjang]

After #12277, the new Weight struct has its fields all #[codec(compact)] by default, and so the struct itself does not need to be #[pallet::compact] anymore.