com.hazelcast.internal.util.SetUtil Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2021, 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.util;
import com.hazelcast.internal.util.collection.ImmutablePartitionIdSet;
import com.hazelcast.internal.util.collection.PartitionIdSet;
import java.util.Collection;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Set;
/**
* Utility class for Sets.
*/
public final class SetUtil {
private static final float HASHSET_DEFAULT_LOAD_FACTOR = 0.75f;
private SetUtil() {
}
/**
* Utility method that creates an {@link java.util.HashSet} with its initialCapacity calculated
* to minimize rehash operations
*/
public static Set createHashSet(int expectedMapSize) {
final int initialCapacity = (int) (expectedMapSize / HASHSET_DEFAULT_LOAD_FACTOR) + 1;
return new HashSet(initialCapacity, HASHSET_DEFAULT_LOAD_FACTOR);
}
/**
* Utility method that creates an {@link java.util.LinkedHashSet} with its initialCapacity calculated
* to minimize rehash operations
*/
public static Set createLinkedHashSet(int expectedMapSize) {
final int initialCapacity = (int) (expectedMapSize / HASHSET_DEFAULT_LOAD_FACTOR) + 1;
return new LinkedHashSet(initialCapacity, HASHSET_DEFAULT_LOAD_FACTOR);
}
public static PartitionIdSet singletonPartitionIdSet(int partitionCount, int partitionId) {
PartitionIdSet set = new PartitionIdSet(partitionCount);
set.add(partitionId);
return set;
}
public static PartitionIdSet immutablePartitionIdSet(int partitionCount, Collection partitionIds) {
return new ImmutablePartitionIdSet(partitionCount, partitionIds);
}
public static PartitionIdSet allPartitionIds(int partitionCount) {
PartitionIdSet set = new PartitionIdSet(partitionCount);
set.complement();
return set;
}
}