Trait raft_engine::internals::ReplayMachine

pub trait ReplayMachine: Send {
    // Required methods
    fn replay(
        &mut self,
        item_batch: LogItemBatch,
        file_id: FileId
    ) -> Result<()>;
    fn merge(&mut self, rhs: Self, queue: LogQueue) -> Result<()>;
}

ReplayMachine is a type of deterministic state machine that obeys associative law.

Sequentially arranged log items can be divided and replayed to several ReplayMachines, and their merged state will be the same as when replayed to one single ReplayMachine.

This abstraction is useful for recovery in parallel: a set of log files can be replayed in a divide-and-conquer fashion.

Required Methods

fn replay(&mut self, item_batch: LogItemBatch, file_id: FileId) -> Result<()>

Inputs a batch of log items from the given file to this machine. Returns whether the input sequence up till now is accepted.

fn merge(&mut self, rhs: Self, queue: LogQueue) -> Result<()>

Merges with another ReplayMachine that has consumed newer log items in the same input sequence.

Implementors

impl<A: AllocatorTrait> ReplayMachine for MemTableRecoverContext<A>