https://github.com/eclipse/eclipse-collections/eclipse-collections-api: Eclipse Collections is a collections framework for Java. It has JDK-compatible List, Set and Map implementations with a rich API and set of utility classes that work with any JDK compatible Collections, Arrays, Maps or Strings. The iteration protocol was inspired by the Smalltalk collection framework.
  • Craig P. Motlin
  • Donald Raab
  • Mohammad A. Rezaei
  • Hiroshi Ito
  • Nikhil J. Nanivadekar 
/*
 * Copyright (c) 2015 Goldman Sachs.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v. 1.0 which accompany this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 */

package org.eclipse.collections.api.set;

public interface Pool<V>
{
    
Locates an object in the pool which is equal to key. 
Params:
  • key – the value to look for
Returns:The object reference in the pool equal to key or null.
/**
     * Locates an object in the pool which is equal to {@code key}.
     *
     * @param key the value to look for
     * @return The object reference in the pool equal to key or null.
     */
    V get(V key);

    void clear();

    
Puts key into the pool. If there is no existing object that is equal to key, key will be added to the pool and the return value will be the same instance. If there is an existing object in the pool that is equal to key, the pool will remain unchanged and the pooled instance will be is returned. 
Params:
  • key – the value to add if not in the pool
Returns:the object reference in the pool equal to key (either key itself or the existing reference)
/**
     * Puts {@code key} into the pool. If there is no existing object that is equal
     * to key, key will be added to the pool and the return value will be the same instance.
     * If there is an existing object in the pool that is equal to {@code key}, the pool will remain unchanged
     * and the pooled instance will be is returned.
     *
     * @param key the value to add if not in the pool
     * @return the object reference in the pool equal to key (either key itself or the existing reference)
     */
    V put(V key);

    int size();

    
Locates an object in the pool which is equal to key and removes it. 
Params:
  • key – object to remove
Returns:The object reference in the pool equal to key or null.
/**
     * Locates an object in the pool which is equal to {@code key} and removes it.
     *
     * @param key object to remove
     * @return The object reference in the pool equal to key or null.
     */
    V removeFromPool(V key);
}