Struct CheckpointStateMachine 

pub struct CheckpointStateMachine<Clock: LogicalClock, A: ConcurrentAllocator = TursoAllocator> { /* private fields */ }

A state machine that performs a complete checkpoint operation on the MVCC store.

The checkpoint process:

1. Takes a blocking lock on the database so that no other transactions can run during the checkpoint.
2. Determines which row versions should be written to the B-tree.
3. Begins a pager transaction
4. Writes all the selected row versions to the B-tree.
5. Commits the pager transaction, effectively flushing to the WAL
6. Immediately does a TRUNCATE checkpoint from the WAL to the DB
7. Fsync the DB file
8. Truncate logical log to 0 (salt regenerated in memory), fsync, then truncate WAL
9. Releases the blocking_checkpoint_lock

Passive mode defers step 1 until publish and runs collection/write concurrently; the durable outcome (WAL backfill, log truncate, metadata) is the same.

Implementations

impl<Clock: LogicalClock, A: ConcurrentAllocator> CheckpointStateMachine<Clock, A>

pub fn new( pager: Arc<Pager>, mvstore: Arc<MvStore<Clock, A>>, connection: Arc<Connection>, update_transaction_state: bool, sync_mode: SyncMode, database_id: usize, mode: CheckpointMode, ) -> Self

pub fn cleanup_after_external_io_error(&mut self, err: LimboError) -> Result<()>

Cleanup path for I/O errors that happen while waiting on completions outside of step(). This mirrors step() error handling and also resets pager/WAL checkpoint bookkeeping.

Trait Implementations

impl<Clock: LogicalClock, A: ConcurrentAllocator> StateTransition for CheckpointStateMachine<Clock, A>

type Context = ()

type SMResult = CheckpointResult

fn step( &mut self, _context: &Self::Context, ) -> Result<TransitionResult<Self::SMResult>>

Transition the state machine to the next state.

fn finalize(&mut self, _context: &Self::Context) -> Result<()>

Finalize the state machine.

fn is_finalized(&self) -> bool

Check if the state machine is finalized.