geode-core/src/main/java/org/apache/geode/cache/query/internal/index/IndexConcurrentHashSet.java

/*
 * 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.geode.cache.query.internal.index;

import java.util.Collection;

import org.apache.geode.internal.concurrent.CompactConcurrentHashSet2;

/**
 * This class overrides the size method to make it non-blocking for our query engine. size() is only
 * called index size estimation for selecting best index for a query which can be approximate so it
 * does NOT have to lock internal segments for accurate count.
 *
 * @param <E>
 * @since GemFire 7.0
 */
public class IndexConcurrentHashSet<E> extends CompactConcurrentHashSet2<E> {


  public IndexConcurrentHashSet() {
    super();
  }

  public IndexConcurrentHashSet(Collection<? extends E> m) {
    super(m);
  }

  public IndexConcurrentHashSet(int initialCapacity, float loadFactor, int concurrencyLevel) {
    super(initialCapacity, loadFactor, concurrencyLevel);
  }

  public IndexConcurrentHashSet(int initialCapacity, float loadFactor) {
    super(initialCapacity, loadFactor);
  }

  public IndexConcurrentHashSet(int initialCapacity) {
    super(initialCapacity);
  }

  /*
   * Returns the number of values in this set. If the set contains more than
   * <tt>Integer.MAX_VALUE</tt> elements, returns <tt>Integer.MAX_VALUE</tt>.
   *
   * @return the number of values in this set
   *
   * Note: This has been modified for GemFire Indexes.
   */
  // @Override
  // public int size() {
  // long trueSize = mappingCount();
  // if (trueSize > Integer.MAX_VALUE) {
  // return Integer.MAX_VALUE;
  // } else {
  // return (int)trueSize;
  // }
  // }
}