AnnouncementRegistry.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
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 * 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,
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package org.apache.sling.discovery.base.connectors.announcement;

import java.util.Collection;

import org.apache.sling.discovery.ClusterView;
import org.apache.sling.discovery.InstanceDescription;

/**
 * The announcement registry keeps track of all the announcement that this
 * instance either received by a joined topology connector or that a topology
 * connector inherited from the counterpart (the topology connector servlet)
 */
public interface AnnouncementRegistry {

    /** 
     * Register the given announcement - and returns the backoff interval (in seconds)
     * for stable connectors
     * - or -1 if the registration was not successful (likely indicating a loop) 
     * @return the backoff interval (in seconds) for stable connectors
     * - or -1 if the registration was not successful (likely indicating a loop) 
     */
    long registerAnnouncement(Announcement topologyAnnouncement);
    
    /** list all announcements that were received by instances in the local cluster **/
    Collection<Announcement> listAnnouncementsInSameCluster(ClusterView localClusterView);
    
    /** list all announcements that were received (incoming or inherited) by this instance **/
    Collection<Announcement> listLocalAnnouncements();
    
    /** list all announcements that this instance received (incoming) **/ 
    Collection<CachedAnnouncement> listLocalIncomingAnnouncements();
    
    /** Check for expired announcements and remove any if applicable **/
    void checkExpiredAnnouncements();

    /** Returns the list of instances contained in all non-expired announcements of this registry **/
    Collection<InstanceDescription> listInstances(ClusterView localClusterView);

    /** Add all registered announcements to the given target announcement that are accepted by the given filter **/
    void addAllExcept(Announcement target, ClusterView localClusterView, AnnouncementFilter filter);

    /** Unregister the announcement owned by the given slingId **/
    void unregisterAnnouncement(String ownerId);

    /** Whether or not the given owner has an active (ie not expired) announcement registered **/
    boolean hasActiveAnnouncement(String ownerId);

}