org.neo4j.causalclustering.core.state.machines.id

Class ReplicatedIdAllocationStateMachine

java.lang.Object

org.neo4j.causalclustering.core.state.machines.id.ReplicatedIdAllocationStateMachine

All Implemented Interfaces:

StateMachine<ReplicatedIdAllocationRequest>

public class ReplicatedIdAllocationStateMachine
extends Object
implements StateMachine<ReplicatedIdAllocationRequest>

Keeps track of global id allocations for all members.

Constructor Summary

Constructors

Constructor and Description
ReplicatedIdAllocationStateMachine(StateStorage<IdAllocationState> storage)

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

ReplicatedIdAllocationStateMachine

public ReplicatedIdAllocationStateMachine(StateStorage<IdAllocationState> storage)

Method Detail

applyCommand

public void applyCommand(ReplicatedIdAllocationRequest request,
                         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<ReplicatedIdAllocationRequest>

Parameters:

request - 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<ReplicatedIdAllocationRequest>

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<ReplicatedIdAllocationRequest>

Returns:

the last applied index for this state machine

snapshot

public IdAllocationState snapshot()

installSnapshot

public void installSnapshot(IdAllocationState snapshot)