001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.cloud;
018
019import java.util.Collection;
020import java.util.Collections;
021import java.util.Map;
022import java.util.Optional;
023
024import org.apache.camel.CamelContextAware;
025import org.apache.camel.Ordered;
026import org.apache.camel.Service;
027import org.apache.camel.spi.IdAware;
028
029public interface ServiceRegistry extends Service, CamelContextAware, IdAware, Ordered {
030
031    @Override
032    default int getOrder() {
033        return Ordered.LOWEST;
034    }
035
036    /**
037     * Attributes associated to the service.
038     */
039    default Map<String, Object> getAttributes() {
040        return Collections.emptyMap();
041    }
042
043    /**
044     * Register the service definition.
045     *
046     * @param definition the service definition
047     */
048    void register(ServiceDefinition definition);
049
050
051    /**
052     * Remove the service definition.
053     *
054     * @param definition the service definition
055     */
056    void deregister(ServiceDefinition definition);
057
058    /**
059     * A selector used to pick up a service among a list.
060     */
061    @FunctionalInterface
062    interface Selector {
063        /**
064         * Select a specific ServiceRegistry instance among a collection.
065         */
066        Optional<ServiceRegistry> select(Collection<ServiceRegistry> services);
067    }
068}