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   1 /**
   2  * Copyright (c) 2010-2022 Contributors to the openHAB project
   3  *
   4  * See the NOTICE file(s) distributed with this work for additional
   5  * information.
   6  *
   7  * This program and the accompanying materials are made available under the
   8  * terms of the Eclipse Public License 2.0 which is available at
   9  * http://www.eclipse.org/legal/epl-2.0
  10  *
  11  * SPDX-License-Identifier: EPL-2.0
  12  */
  13 package org.openhab.binding.mqtt.internal;
  14
  15 import java.util.Collections;
  16 import java.util.Map;
  17 import java.util.Set;
  18 import java.util.WeakHashMap;
  19 import java.util.concurrent.ConcurrentHashMap;
  20 import java.util.stream.Collectors;
  21 import java.util.stream.Stream;
  22
  23 import org.eclipse.jdt.annotation.NonNullByDefault;
  24 import org.eclipse.jdt.annotation.Nullable;
  25 import org.openhab.binding.mqtt.MqttBindingConstants;
  26 import org.openhab.binding.mqtt.discovery.MQTTTopicDiscoveryParticipant;
  27 import org.openhab.binding.mqtt.discovery.MQTTTopicDiscoveryService;
  28 import org.openhab.binding.mqtt.handler.AbstractBrokerHandler;
  29 import org.openhab.binding.mqtt.handler.BrokerHandler;
  30 import org.openhab.core.thing.Bridge;
  31 import org.openhab.core.thing.Thing;
  32 import org.openhab.core.thing.ThingTypeUID;
  33 import org.openhab.core.thing.binding.BaseThingHandlerFactory;
  34 import org.openhab.core.thing.binding.ThingHandler;
  35 import org.openhab.core.thing.binding.ThingHandlerFactory;
  36 import org.osgi.service.component.annotations.Component;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39
  40 /**
  41  * The {@link MqttBrokerHandlerFactory} is responsible for creating things and thing
  42  * handlers. It keeps reference to all handlers and implements the {@link MQTTTopicDiscoveryService} service
  43  * interface, so service consumers can subscribe to a topic on all available broker connections.
  44  *
  45  * @author David Graeff - Initial contribution
  46  */
  47 @NonNullByDefault
  48 @Component(service = { ThingHandlerFactory.class,
  49         MQTTTopicDiscoveryService.class }, configurationPid = "MqttBrokerHandlerFactory")
  50 public class MqttBrokerHandlerFactory extends BaseThingHandlerFactory implements MQTTTopicDiscoveryService {
  51
  52     private static final Set<ThingTypeUID> SUPPORTED_THING_TYPES_UIDS = Stream
  53             .of(MqttBindingConstants.BRIDGE_TYPE_BROKER).collect(Collectors.toSet());
  54
  55     private final Logger logger = LoggerFactory.getLogger(MqttBrokerHandlerFactory.class);
  56
  57     /**
  58      * This Map provides a lookup between a Topic string (key) and a Set of MQTTTopicDiscoveryParticipants (value),
  59      * where the Set itself is a list of participants which are subscribed to the respective Topic.
  60      */
  61     protected final Map<String, Set<MQTTTopicDiscoveryParticipant>> discoveryTopics = new ConcurrentHashMap<>();
  62
  63     /**
  64      * This Set contains a list of all the Broker handlers that have been created by this factory
  65      */
  66     protected final Set<AbstractBrokerHandler> handlers = Collections
  67             .synchronizedSet(Collections.newSetFromMap(new WeakHashMap<>()));
  68
  69     @Override
  70     public boolean supportsThingType(ThingTypeUID thingTypeUID) {
  71         return SUPPORTED_THING_TYPES_UIDS.contains(thingTypeUID);
  72     }
  73
  74     /**
  75      * Add the given broker handler to the list of known handlers. And then iterate over all topics and their respective
  76      * list of listeners, and register the respective new listener and topic with the given new broker handler.
  77      */
  78     protected void createdHandler(AbstractBrokerHandler handler) {
  79         handlers.add(handler);
  80         discoveryTopics.forEach((topic, listeners) -> {
  81             listeners.forEach(listener -> {
  82                 handler.registerDiscoveryListener(listener, topic);
  83             });
  84         });
  85     }
  86
  87     @Override
  88     protected @Nullable ThingHandler createHandler(Thing thing) {
  89         if (!(thing instanceof Bridge)) {
  90             throw new IllegalStateException("A bridge type is expected");
  91         }
  92         final ThingTypeUID thingTypeUID = thing.getThingTypeUID();
  93
  94         final AbstractBrokerHandler handler;
  95         if (thingTypeUID.equals(MqttBindingConstants.BRIDGE_TYPE_BROKER)) {
  96             handler = new BrokerHandler((Bridge) thing);
  97         } else {
  98             throw new IllegalStateException("Not supported " + thingTypeUID.toString());
  99         }
 100         createdHandler(handler);
 101         return handler;
 102     }
 103
 104     /**
 105      * This factory also implements {@link MQTTTopicDiscoveryService} so consumers can subscribe to
 106      * a MQTT topic that is registered on all available broker connections.
 107      *
 108      * Checks each topic, and if the listener is not already in the listener list for that topic, adds itself from that
 109      * list, and registers itself and the respective topic with all the known brokers.
 110      */
 111     @Override
 112     @SuppressWarnings("null")
 113     public void subscribe(MQTTTopicDiscoveryParticipant listener, String topic) {
 114         Set<MQTTTopicDiscoveryParticipant> listeners = discoveryTopics.computeIfAbsent(topic,
 115                 t -> ConcurrentHashMap.newKeySet());
 116         if (listeners.add(listener)) {
 117             handlers.forEach(broker -> broker.registerDiscoveryListener(listener, topic));
 118         }
 119     }
 120
 121     /**
 122      * This factory also implements {@link MQTTTopicDiscoveryService} so consumers can unsubscribe from
 123      * a MQTT topic that is registered on all available broker connections.
 124      *
 125      * Checks each topic, and if the listener is in the listener list for that topic, removes itself from that list, and
 126      * unregisters itself and the respective topic from all the known brokers.
 127      */
 128     @Override
 129     public void unsubscribe(MQTTTopicDiscoveryParticipant listener) {
 130         discoveryTopics.forEach((topic, listeners) -> {
 131             if (listeners.remove(listener)) {
 132                 handlers.forEach(broker -> broker.unregisterDiscoveryListener(listener, topic));
 133             }
 134         });
 135     }
 136
 137     @Override
 138     public void publish(String topic, byte[] payload, int qos, boolean retain) {
 139         handlers.forEach(handler -> {
 140             handler.getConnectionAsync().thenAccept(connection -> {
 141                 connection.publish(topic, payload, qos, retain);
 142             });
 143         });
 144     }
 145 }