Functional StatefulBlock

[aaronbuchwald]

StatefulBlock and Avalanche consensus engine guarantee that a block is only verified when its parent (and all ancestors) have been verified and accepted when its parent (and all ancestors have been accepted.

Switch StatefulBlock to support a functional flow that the chain/DSMR package can implement of: ExecutionBlock -> ExecutedBlock -> AcceptedBlock.

The chain then takes responsibility for committing its own state and the VM is responsible for passing in the required input types and maintaining a chain index that guarantees the last accepted block stored on disk is ahead of the last accepted block committed by the chain. This ensures that when writing to two different databases, if the chain is behind ie. merkle root is at block N-2, the VM has the blocks required to re-execute and re-compute the last accepted state.