java/org/apache/catalina/tribes/MembershipService.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.catalina.tribes;


/**
 * The <code>MembershipService</code> interface is the membership component at the bottom layer, the IO layer (for
 * layers see the javadoc for the {@link Channel} interface).
 */
public interface MembershipService {

    int MBR_RX = Channel.MBR_RX_SEQ;
    int MBR_TX = Channel.MBR_TX_SEQ;

    /**
     * Sets the properties for the membership service. This must be called before the <code>start()</code> method is
     * called. The properties are implementation specific.
     *
     * @param properties - to be used to configure the membership service.
     */
    void setProperties(java.util.Properties properties);

    /**
     * @return the properties for the configuration used.
     */
    java.util.Properties getProperties();

    /**
     * Starts the membership service. If a membership listeners is added the listener will start to receive membership
     * events. Performs a start level 1 and 2
     *
     * @throws Exception if the service fails to start.
     */
    void start() throws Exception;

    /**
     * Starts the membership service. If a membership listeners is added the listener will start to receive membership
     * events.
     *
     * @param level - level MBR_RX starts listening for members, level MBR_TX starts broadcasting the server
     *
     * @throws Exception                          if the service fails to start.
     * @throws java.lang.IllegalArgumentException if the level is incorrect.
     */
    void start(int level) throws Exception;


    /**
     * Stops the membership service. If a membership listeners is added the listener will start to receive membership
     * events.
     *
     * @param level - level MBR_RX stops listening for members, level MBR_TX stops broadcasting the server
     *
     * @throws java.lang.IllegalArgumentException if the level is incorrect.
     */
    void stop(int level);

    /**
     * @return true if the group contains members
     */
    boolean hasMembers();

    /**
     * Retrieve the specified member from the membership.
     *
     * @param mbr The member to retrieve
     *
     * @return the member
     */
    Member getMember(Member mbr);

    /**
     * @return an array of all the members in the cluster.
     */
    Member[] getMembers();

    /**
     * Get the local member.
     *
     * @return the member object that defines this member
     *
     * @param incAliveTime <code>true</code> to set the alive time on the local member
     */
    Member getLocalMember(boolean incAliveTime);

    /**
     * @return all members by name
     */
    String[] getMembersByName();

    /**
     * Get a member.
     *
     * @param name The member name
     *
     * @return the member
     */
    Member findMemberByName(String name);

    /**
     * Sets the local member properties for broadcasting.
     *
     * @param listenHost Listen to host
     * @param listenPort Listen to port
     * @param securePort Use a secure port
     * @param udpPort    Use UDP
     */
    void setLocalMemberProperties(String listenHost, int listenPort, int securePort, int udpPort);

    /**
     * Sets the membership listener, only one listener can be added. If you call this method twice, the last listener
     * will be used.
     *
     * @param listener The listener
     */
    void setMembershipListener(MembershipListener listener);

    /**
     * Removes the membership listener.
     */
    void removeMembershipListener();

    /**
     * Set a payload to be broadcasted with each membership broadcast.
     *
     * @param payload byte[]
     */
    void setPayload(byte[] payload);

    /**
     * Set the associated domain.
     *
     * @param domain the domain
     */
    void setDomain(byte[] domain);

    /**
     * Broadcasts a message to all members.
     *
     * @param message The message to broadcast
     *
     * @throws ChannelException Message broadcast failed
     */
    void broadcast(ChannelMessage message) throws ChannelException;

    /**
     * Return the channel that is related to this MembershipService
     *
     * @return Channel
     */
    Channel getChannel();

    /**
     * Set the channel that is related to this MembershipService
     *
     * @param channel The channel
     */
    void setChannel(Channel channel);

    /**
     * Get the MembershipProvider
     *
     * @return MembershipProvider
     */
    MembershipProvider getMembershipProvider();
}