/*
 * 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.webbeans.spi;

/**
 * Conversation related SPI.
 * @version $Rev$ $Date$
 */
public interface ConversationService
{
    /**
     * Gets the current propagated conversation id or {@code null}
     * if there is no conversation.
     *
     * @return the current conversation id
     */
    String getConversationId();

    /**
     * Generate a new conversation Id which is unique for a certain session.
     * We need to do this via a pluggable Service as it makes a huge difference whether
     * the id has to be unique on a single JVM or on multiple of them.
     * If we have a ServletSession then we only have to be unique per Session
     * and thus can make the handling much easier.
     */
    String generateConversationId();

}
