// Copyright 2017 JanusGraph Authors
//
// 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 org.janusgraph.util.datastructures;
import com.google.common.base.Preconditions;
/**
* Immutable set of integers
*
* @author Matthias Broecheler (me@matthiasb.com)
*/
public class ImmutableIntSet implements IntSet {
private final int[] values;
private final int hashcode;
public ImmutableIntSet(int[] values) {
Preconditions.checkNotNull(values);
Preconditions.checkArgument(values.length > 0);
this.values = values;
hashcode = ArraysUtil.sum(values);
}
public ImmutableIntSet(int value) {
this(new int[]{value});
}
@Override
public boolean add(int value) {
throw new UnsupportedOperationException("This IntSet is immutable");
}
@Override
public boolean addAll(int[] values) {
throw new UnsupportedOperationException("This IntSet is immutable");
}
@Override
public boolean contains(int value) {
for (int i = 0; i < values.length; i++) {
if (values[i] == value) return true;
}
return false;
}
@Override
public int[] getAll() {
return values;
}
@Override
public int size() {
return values.length;
}
@Override
public int hashCode() {
return hashcode;
}
@Override
public boolean equals(Object other) {
if (this == other) return true;
else if (!(other instanceof IntSet)) return false;
IntSet oth = (IntSet) other;
for (int i = 0; i < values.length; i++) {
if (!oth.contains(values[i])) return false;
}
return size() == oth.size();
}
}