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/*
* Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you
* may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.cache;
import java.io.*;
/**
* Enumerated type for region subscription interest policy.
* The interest policy specifies what data a subscriber is interested in having
* in it's region.
*
* @author Darrel Schneider
*
*
* @see SubscriptionAttributes
*
* @since 5.0
*/
public class InterestPolicy implements java.io.Serializable {
private static final long serialVersionUID = 1567179436331385968L;
private static byte nextOrdinal = 0;
private static final InterestPolicy[] VALUES = new InterestPolicy[2];
/**
* This subscriber is interested in all data.
* More specifically operations done in this cache and
* distributed operations done in remote caches.
*
* When combined with {@link DataPolicy#EMPTY} this region will receive
* events for every distributed operation but will not store the data.
*
* When combined with {@link DataPolicy#NORMAL} or
* {@link DataPolicy#PRELOADED} this region will accept
* {@link Region#create(Object, Object)} operations done remotely. Without
* the ALL interest policy, NORMAL and
* PRELOADED ignore creates that the region
* does not have an existing entry for.
*
* When combined with the {@link DataPolicy#withReplication replication
* policies} this interest has no effect.
*
* When combined with {@link DataPolicy#PARTITION} this interest policy
* causes cache listeners to be notified of changes regardless of the
* physical location of the data affected. That is, a listener in a VM
* using this policy will receive notification of all changes to the
* partitioned region.
*/
public static final InterestPolicy ALL = new InterestPolicy("ALL");
/**
* This subscriber is interested in data that is already in its cache.
* More specifically operations done in this cache and
* distributed operations done in remote caches.
*
* When combined with {@link DataPolicy#EMPTY} this region will never
* receive events for distributed operations since its content is always
* empty. It will continue to get events for operations done locally.
*
* When combined with {@link DataPolicy#NORMAL} or
* {@link DataPolicy#PRELOADED} this region will accept remote operations
* done to entries it already has in its cache.
*
* When combined with the {@link DataPolicy#withReplication replication
* policies} * this interest has no effect.
*
* When combined with {@link DataPolicy#PARTITION} this interest policy
* causes cache listeners to be notified in the VM holding the affected data.
* That is, listeners are only notified if the affected* key-value pair is
* in the same process as the listener.
*/
public static final InterestPolicy CACHE_CONTENT = new InterestPolicy("CACHE_CONTENT");
/**
* The interest policy used by default; it is {@link #CACHE_CONTENT}.
*/
public static final InterestPolicy DEFAULT = CACHE_CONTENT;
/** The name of this mirror type. */
private final transient String name;
/** used as ordinal to represent this InterestPolicy */
public final byte ordinal;
private Object readResolve() throws ObjectStreamException {
return VALUES[ordinal]; // Canonicalize
}
/** Creates a new instance of InterestPolicy. */
private InterestPolicy(String name) {
this.name = name;
this.ordinal = nextOrdinal++;
VALUES[this.ordinal] = this;
}
/** Return the InterestPolicy represented by specified ordinal */
public static InterestPolicy fromOrdinal(byte ordinal) {
return VALUES[ordinal];
}
/**
* Return true if this policy is {@link #ALL}.
* @return true if this policy is {@link #ALL}.
*/
public boolean isAll() {
return this == ALL;
}
/**
* Return true if this policy is {@link #CACHE_CONTENT}.
* @return true if this policy is {@link #CACHE_CONTENT}.
*/
public boolean isCacheContent() {
return this == CACHE_CONTENT;
}
/**
* Return true if this policy is the default.
* @return true if this policy is the default.
*/
public boolean isDefault() {
return this == DEFAULT;
}
/** Returns a string representation for this interest policy.
* @return the name of this interest policy.
*/
@Override
public String toString() {
return this.name;
}
}