pub trait DurablePersistence { }Expand description
Assumption (Durable persistence). A correct validator persists its
ChainManager state before releasing a vote to the network,
and that state survives a crash.
The implementation is structured to make this hold: every path in
linera_core::chain_worker::state that mutates the manager calls self.save() before
returning the chain info response that carries the vote — try_handle_block_proposal after
create_vote, process_validated_block after create_final_vote,
vote_for_leader_timeout after create_timeout_vote, and vote_for_fallback after
vote_fallback. The response projection is ChainManagerInfo.
Without this, a crash could lose the record of a vote and let the validator vote again,
breaking OneValidationVotePerRound and OneConfirmationVotePerRound, which are the
only places where the assumption is consumed. It is one half of a discipline whose other half
— that an effect already persisted is never lost — is linera_core::proof::availability. A
validator that violates it is faulty in the sense of CorrectValidator, and is counted
against MaxByzantineWeight.