com.hazelcast.org.apache.calcite.sql.util.IdPair Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you 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.org.apache.calcite.sql.util;
import com.hazelcast.org.checkerframework.checker.nullness.qual.Nullable;
import java.util.List;
import java.util.Map;
import java.util.Objects;
/** Similar to {@link com.hazelcast.org.apache.calcite.util.Pair} but identity is based
* on identity of values.
*
* Also, uses {@code hashCode} algorithm of {@link List},
* not {@link Map.Entry#hashCode()}.
*
* @param Left type
* @param Right type
*/
public class IdPair {
final L left;
final R right;
/** Creates an IdPair. */
public static IdPair of(L left, R right) {
return new IdPair<>(left, right);
}
protected IdPair(L left, R right) {
this.left = Objects.requireNonNull(left, "left");
this.right = Objects.requireNonNull(right, "right");
}
@Override public String toString() {
return left + "=" + right;
}
@Override public boolean equals(@Nullable Object obj) {
return obj == this
|| obj instanceof IdPair
&& left == ((IdPair) obj).left
&& right == ((IdPair) obj).right;
}
@Override public int hashCode() {
return (31
+ System.identityHashCode(left)) * 31
+ System.identityHashCode(right);
}
}