com.hazelcast.internal.eviction.CompositeEvictionChecker Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2020, Hazelcast, 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.
*/
package com.hazelcast.internal.eviction;
import com.hazelcast.util.Preconditions;
/**
* {@link EvictionChecker} implementation for composing
* results of given {@link EvictionChecker} instances.
*/
public abstract class CompositeEvictionChecker
implements EvictionChecker {
protected final EvictionChecker[] evictionCheckers;
protected CompositeEvictionChecker(EvictionChecker... evictionCheckers) {
this.evictionCheckers = evictionCheckers;
}
/**
* Operator for composing results of given {@link EvictionChecker} instances.
*/
public static enum CompositionOperator {
/**
* Result is true if results of all given {@link EvictionChecker} instances
* have reached to max-size, otherwise false.
*/
AND,
/**
* Result is true if result of any given {@link EvictionChecker} instances
* have reached to max-size, otherwise false.
*/
OR;
}
public static CompositeEvictionChecker newCompositeEvictionChecker(CompositionOperator compositionOperator,
EvictionChecker... evictionCheckers) {
Preconditions.isNotNull(compositionOperator, "composition");
Preconditions.isNotNull(evictionCheckers, "evictionCheckers");
if (evictionCheckers.length == 0) {
throw new IllegalArgumentException("EvictionCheckers cannot be empty!");
}
switch (compositionOperator) {
case AND:
return new CompositeEvictionCheckerWithAndComposition(evictionCheckers);
case OR:
return new CompositeEvictionCheckerWithOrComposition(evictionCheckers);
default:
throw new IllegalArgumentException("Invalid composition operator: " + compositionOperator);
}
}
private static final class CompositeEvictionCheckerWithAndComposition
extends CompositeEvictionChecker {
private CompositeEvictionCheckerWithAndComposition(EvictionChecker... evictionCheckers) {
super(evictionCheckers);
}
@Override
public boolean isEvictionRequired() {
for (EvictionChecker evictionChecker : evictionCheckers) {
if (!evictionChecker.isEvictionRequired()) {
return false;
}
}
return true;
}
}
private static final class CompositeEvictionCheckerWithOrComposition
extends CompositeEvictionChecker {
private CompositeEvictionCheckerWithOrComposition(EvictionChecker... evictionCheckers) {
super(evictionCheckers);
}
@Override
public boolean isEvictionRequired() {
for (EvictionChecker evictionChecker : evictionCheckers) {
if (evictionChecker.isEvictionRequired()) {
return true;
}
}
return false;
}
}
}