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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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.atlas.repository.util;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  public class UniqueList<T> {
      private final List<T> list = new ArrayList<>();
      private final Set<T>  set  = new HashSet<>();
  
      public void add(T e) {
          if (set.contains(e)) {
              return;
          }
  
          list.add(e);
          set.add(e);
      }
  
      public void addAll(UniqueList<T> uniqueList) {
          for (T item : uniqueList.list) {
              if (set.contains(item)) {
                  continue;
              }
  
              set.add(item);
              list.add(item);
          }
      }
  
      public void addAll(Collection<T> collection) {
          for (T item : collection) {
              add(item);
          }
      }
  
      public T remove(int index) {
          T e = list.remove(index);
          set.remove(e);
          return e;
      }
  
      public boolean contains(T e) {
          return set.contains(e);
      }
  
      public int size() {
          return list.size();
      }
  
      public boolean isEmpty() {
          return list.isEmpty();
      }
  
      public void clear() {
          list.clear();
          set.clear();
      }
  
      public List<T> getList() {
          return list;
      }
  }
  