/*
 * Copyright 2010 JBoss Inc
 *
 * Licensed 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.drools.runtime.process;

import java.util.Collection;

/**
 * A node instance container is a container that can contain
 * (zero or more) node instances.
 */
public interface NodeInstanceContainer {

    /**
     * Returns all node instances that are currently active
     * within this container.
     *
     * @return the list of node instances currently active
     */
    Collection<NodeInstance> getNodeInstances();
    
    /**
     * Returns the node instance with the given id, or <code>null</code>
     * if the node instance cannot be found.
     * 
     * @param nodeInstanceId
     * @return the node instance with the given id
     */
    NodeInstance getNodeInstance(long nodeInstanceId);

}
