content: /*
   * 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 org.apache.activemq.artemis.api.core;
  
  import java.io.Serializable;
  import java.util.Objects;
  
  /**
   * A Pair is a holder for 1 object and 'a' being greater or equal than 0.
   * <p>
   * This is a utility class.
   */
  public class ObjLongPair<A> implements Serializable {
  
     private static final long serialVersionUID = 7749478219139339853L;
  
     public static final long NIL = -1;
  
     public ObjLongPair(final A a, final long b) {
        this.a = a;
        this.b = b;
        if (b < 0 && b != NIL) {
           throw new IllegalStateException("b must be >= 0 or == NIL = " + NIL);
        }
     }
  
     public ObjLongPair(final A a) {
        this.a = a;
        this.b = NIL;
     }
  
     private A a;
     private long b;
  
     @Override
     public int hashCode() {
        if (a == null && b == NIL) {
           return super.hashCode();
        }
        // it's ok to use b to compute hashCode although NIL
        return Objects.hash(a, b);
     }
  
     @Override
     public boolean equals(final Object obj) {
        if (obj == this) {
           return true;
        }
        if (!(obj instanceof ObjLongPair other)) {
           return false;
        }
  
        return Objects.equals(other.a, a) &&
               other.b == b;
     }
  
     @Override
     public String toString() {
        return "ObjLongPair[a=" + a + ", b=" + (b == NIL ? "NIL" : b) + "]";
     }
  
     public void setA(A a) {
        if (this.a == a) {
           return;
        }
        this.a = a;
     }
  
     public A getA() {
        return a;
     }
  
     public void setB(long b) {
        if (b < 0 && b != NIL) {
           throw new IllegalStateException("b must be >= 0 or == NIL = " + NIL);
        }
        this.b = b;
     }
  
     public long getB() {
        return b;
     }
  }
  