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.ambari.server.utils;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  
  /**
   * Static Helper methods for sets
   */
  public class SetUtils {
  
    /**
     * Split a set into subsets
     * @param original The original set to be split
     * @param subsetSize Size of the subset (except for final subset)
     * @param <T> Data type of set elements
     * @return List of subsets
     */
    public static <T> List<Set<T>> split(Set<T> original, int subsetSize) {
  
      if(subsetSize <= 0) {
        throw new IllegalArgumentException("Incorrect max size");
      }
  
      if(original == null || original.isEmpty()) {
        return Collections.emptyList();
      }
  
      int subsetCount = (int) (Math.ceil((double)original.size() / subsetSize));
      ArrayList<Set<T>> subsets = new ArrayList<>(subsetCount);
      Iterator<T> iterator = original.iterator();
  
      for(int i = 0; i < subsetCount; i++) {
        Set<T> subset = new LinkedHashSet<>(subsetSize);
        for(int j = 0; j < subsetSize && iterator.hasNext(); j++) {
          subset.add(iterator.next());
        }
        subsets.add(subset);
      }
      return subsets;
    }
  }
  