com.couchbase.client.core.state

Class AbstractStateMachine<S extends Enum>

java.lang.Object

com.couchbase.client.core.state.AbstractStateMachine<S>

All Implemented Interfaces:

Stateful<S>

Direct Known Subclasses:

AbstractDynamicService, AbstractEndpoint, AbstractStateZipper, CouchbaseNode

public class AbstractStateMachine<S extends Enum>
extends Object
implements Stateful<S>

Abstract Stateful implementation which acts like a simple state machine.

This class is thread safe, so state transitions can be issued from any thread without any further synchronization.

Since:

1.0

Author:

Michael Nitschinger

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractStateMachine(S initialState) Creates a new state machine.

Method Summary

Modifier and Type	Method and Description
boolean	hasSubscribers() Returns true if there are subscribers observing the state stream.
boolean	isState(S state) Check if the given state is the same as the current one.
S	state() Returns the current state.
Observable<S>	states() Returns a infinite observable which gets updated when the state of the component changes.
protected void	transitionState(S newState) Transition into a new state.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractStateMachine

protected AbstractStateMachine(S initialState)

Creates a new state machine.

Parameters:

initialState - the initial state of the state machine.

Method Detail

states

public final Observable<S> states()

Description copied from interface: Stateful

Returns a infinite observable which gets updated when the state of the component changes.

Specified by:

states in interface Stateful<S extends Enum>

Returns:

a Observable updated with state transitions.

state

public final S state()

Description copied from interface: Stateful

Returns the current state.

Specified by:

state in interface Stateful<S extends Enum>

Returns:

the current state.

isState

public final boolean isState(S state)

Description copied from interface: Stateful

Check if the given state is the same as the current one.

Specified by:

isState in interface Stateful<S extends Enum>

Parameters:

state - the stats to check against.

Returns:

true if it is the same, false otherwise.

hasSubscribers

public boolean hasSubscribers()

Description copied from interface: Stateful

Returns true if there are subscribers observing the state stream.

Specified by:

hasSubscribers in interface Stateful<S extends Enum>

Returns:

true if at least one does, false otherwise.

transitionState

protected void transitionState(S newState)

Transition into a new state.

This method is intentionally not public, because the subclass should only be responsible for the actual transitions, the other components only react on those transitions eventually.

Parameters:

newState - the states to transition into.