org.opendaylight.yangtools.concepts.Immutable Maven / Gradle / Ivy
/*
* Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.yangtools.concepts;
/**
* Immutable Object - object does not change its externally-observable state during its lifetime.
*
* Marker interface for objects which are immutable. This interface should be used directly on objects, preferably
* final, which are eligible for the JSR-305 {@code javax.annotation.concurrent.Immutable} annotation and objects
* implementing this interface are required to abide to interface contract specified by {@code @Immutable}.
*
*
The reason for the existence of this interface is twofold: unlike {@code @Immutable}, it is visible at runtime and
* objects can be quickly checked for compliance using an 'instanceof' check. This is useful for code which needs to
* capture a point-in-time snapshot of otherwise unknown objects -- a typical example being logging/tracing systems.
* Such systems would normally have to rely on serializing the object to get a stable checkpoint. Objects marked with
* this interface are guaranteed to remain stable, thus already being a checkpoint for all intents and purposes, so
* aside from retaining a reference no further action on them is necessary.
*
*
Implementations of this interface must not change any public state during their entire lifetime.
*
*
This interface is mutually exclusive with {@link Mutable} and other {@link MutationBehaviour}s.
*/
public non-sealed interface Immutable extends MutationBehaviour {
// Marker interface only
}