/**
 * 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.cxf.common.util.factory;

/**
 * Represents a pooling strategy for certain object instance.
 * 
 * @author Ben Yu
 */
public interface Pool extends java.io.Serializable {
    /**
     * Apply the pooling strategy and return an instance from either the pool or
     * the factory.
     * 
     * @param factory the factory to create the object instance.
     * @return the object instance.
     */
    Object getInstance(Factory factory) throws Throwable;

    /**
     * Get the instance that's already pooled.
     * 
     * @param def the default value to return if there's no pooled instance.
     * @return the pooled instance or the default object.
     */
    Object getPooledInstance(Object def);

    /**
     * Is this pool currently having something in cache?
     */
    boolean isPooled();
}
