Refactor Transaction through runtime & primitives about substrate

[rphmeier]

When new end-points are added, they are added not just to their native crate, but also to one if its dependencies, making no sense.

The rationale for this is based on the idea that the runtime implementation is a user of these transaction types as opposed to their owner. We can imagine a tree

                   ----- runtime
                 /
primitives <--- X
                 \
                   ----- stake-wallet-app

for example.

That said, I don't think it's terrible to have crates which are meant to interact with the runtime just link to it and import the types.

What I would really like to avoid is any kind of partial deserialization where we just pass bytes into submodules over and over again.

StartPublicReferendum(Box<Proposal>, Format)

IMO this is actually the correct way to express this relationship in Rust. The alternative is to replace the Box<Proposal> with a Vec<u8> and document that the member must be a correctly serialized proposal (note: this doesn't actually reduce allocations or overhead).

We should steer away from types which can't be resolved at deserialization time in general. Although in this specific case we might just want to consider splitting off StartPublicReferendum from the rest of the proposals: I don't think it's desired behavior to be able to create an unbounded chain of referenda to be started but rather just a single one.

It should be possible to create a generic solution that handles the sub-dispatch to modules.

[gavofyork]

The real dependency graph is actually this:

                         runtime
                         +-------------------------------------+
                         |                                     |
                         |  governance module ++               |
                         |                     |               |
                         |  staking module     |               |
   primitives <----------+                     +-+ dispatcher  |  <-------+ Transaction  <------+  Native Auxilliaries
                         |  system module      |               |
                         |                     |               |
                         |  other modules...  ++               |
                         |                                     |
                         +-------------------------------------+

By placing Transaction in primitives you're entirely disregarding the semantic dependencies and that's why everything is so broken.

[gavofyork]

I understand your reticence (as a good and loyal rustacean) to use serialised data any more than the strict minimum. However, I fear this attitude is rather throwing the rest of the design under the bus for the sake of a fuzzy feeling that you're doing things by the book.

Option 2 would result in one fewer allocation (since you'd never need to fart around with Boxes at all). It might also reduce the complexity of any automated dispatch system since there would be no special cases for functions that accept Proposal.

[gavofyork]

Although in this specific case we might just want to consider splitting off StartPublicReferendum from the rest of the proposals

This sentiment scares me a lot more than late deserialisation.