type Checkpoint interface {
	MarshalCheckpoint() ([]byte, error)
	UnmarshalCheckpoint(blob []byte) error
	VerifyChecksum() error
}

type CheckpointManager interface {
	// CreateCheckpoint persists checkpoint in CheckpointStore. checkpointKey is the key for utilstore to locate checkpoint.
	// For file backed utilstore, checkpointKey is the file name to write the checkpoint data.
	CreateCheckpoint(checkpointKey string, checkpoint Checkpoint) error
	// GetCheckpoint retrieves checkpoint from CheckpointStore.
	GetCheckpoint(checkpointKey string, checkpoint Checkpoint) error
	// WARNING: RemoveCheckpoint will not return error if checkpoint does not exist.
	RemoveCheckpoint(checkpointKey string) error
	// ListCheckpoint returns the list of existing checkpoints.
	ListCheckpoints() ([]string, error)
}