com.hazelcast.map.MapEvictionPolicyComparator Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2024, 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.map;
import com.hazelcast.config.MapConfig;
import com.hazelcast.core.EntryView;
import com.hazelcast.spi.eviction.EvictionPolicyComparator;
/**
* {@link IMap} specific {@link EvictionPolicyComparator} for
* comparing {@link com.hazelcast.core.EntryView}s to be evicted.
*
* Implementors of the comparator have to implement {@code equals}
* and {@code hashCode} methods to support correct config comparison.
*
* Note that you may need to enable per entry stats via
* {@link MapConfig#setPerEntryStatsEnabled} to see
* all fields of entry view in your implementation.
*
* @param type of the key
* @param type of the value
* @see EvictionPolicyComparator
* @see EntryView
* @see com.hazelcast.config.MapConfig#setPerEntryStatsEnabled
*/
@FunctionalInterface
public interface MapEvictionPolicyComparator
extends EvictionPolicyComparator> {
/**
* Compares the given {@link EntryView} instances and
* returns the result.
*
* The result should be one of:
*
* - -1: first entry has higher priority to be evicted
* - 1: second entry has higher priority to be evicted
* - 0: both entries have same priority
*
*
* @param o1 the first {@link EntryView} instance to be compared
* @param o2 the second {@link EntryView} instance to be compared
* @return the result of comparison
*/
@Override
int compare(EntryView o1, EntryView o2);
}