Fast path for importing locally-authored or consensus-checked blocks

[rphmeier]

Right now, we have a block-authoring pattern in Aura where we a) build the block and b) re-execute and import.

In Rhododendron, we either build a proposal or evaluate someone else's and then re-execute and import.

In both situations, there should be a shortcut-path through BlockImport for blocks which already have been executed.

[gnunicorn]

and b) re-execute and import.

You sure? Because the importer does commit the changes (even from the proposer) for said block to the database and the next time execute_and_import is triggered with the same block, it should stop early with the success-code AlreadyInChain, no?

What conditions would lead to us executing the block twice? Which code path even allows for that to happen?

[rphmeier]

As far as i know, we don't pass the state changes generated by building the block to the client. And execute_and_import_block calls the execute_block api, which, if this was a locally authored block, is a re-execution.

[rphmeier]

This will require altering the Proposer trait so some kind of "execution result" is returned as opposed to just the block.