org.neo4j.causalclustering.core.state.machines.locks

Class ReplicatedLockTokenStateMachine

java.lang.Object

org.neo4j.causalclustering.core.state.machines.locks.ReplicatedLockTokenStateMachine

All Implemented Interfaces:

StateMachine<ReplicatedLockTokenRequest>

public class ReplicatedLockTokenStateMachine
extends Object
implements StateMachine<ReplicatedLockTokenRequest>

Listens for ReplicatedLockTokenRequest. Keeps track of the current holder of the replicated token, which is identified by a monotonically increasing id, and an owning member.

Constructor Summary

Constructors

Constructor and Description
ReplicatedLockTokenStateMachine(StateStorage<ReplicatedLockTokenState> storage)

Method Summary

Modifier and Type	Method and Description
void	applyCommand(ReplicatedLockTokenRequest tokenRequest, long commandIndex, Consumer<Result> callback) Apply command to state machine, modifying its internal state.
ReplicatedLockTokenRequest	currentToken()
void	flush() Flushes state to durable storage.
void	installSnapshot(ReplicatedLockTokenState snapshot)
long	lastAppliedIndex() Return the index of the last applied command by this state machine.
ReplicatedLockTokenState	snapshot()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReplicatedLockTokenStateMachine

public ReplicatedLockTokenStateMachine(StateStorage<ReplicatedLockTokenState> storage)

Method Detail

applyCommand

public void applyCommand(ReplicatedLockTokenRequest tokenRequest,
                         long commandIndex,
                         Consumer<Result> callback)

Description copied from interface: StateMachine

Apply command to state machine, modifying its internal state. Implementations should be idempotent, so that the caller is free to replay commands from any point in the log.

Specified by:

applyCommand in interface StateMachine<ReplicatedLockTokenRequest>

Parameters:

tokenRequest - Command to the state machine.

commandIndex - The index of the command.

callback - To be called when a result is produced.

flush

public void flush()
           throws IOException

Description copied from interface: StateMachine

Flushes state to durable storage.

Specified by:

flush in interface StateMachine<ReplicatedLockTokenRequest>

Throws:

IOException

lastAppliedIndex

public long lastAppliedIndex()

Description copied from interface: StateMachine

Return the index of the last applied command by this state machine.

Specified by:

lastAppliedIndex in interface StateMachine<ReplicatedLockTokenRequest>

Returns:

the last applied index for this state machine

snapshot

public ReplicatedLockTokenState snapshot()

installSnapshot

public void installSnapshot(ReplicatedLockTokenState snapshot)

currentToken

public ReplicatedLockTokenRequest currentToken()

Returns:

The currently valid token.