[ISSUE#46] Add support for wildcard subscription

courier-core/api/courier-core.api

@@ -72,6 +72,9 @@ public final class com/gojek/courier/extensions/CollectionExtensionsKt {
 	public static final fun toImmutableSet (Ljava/util/Set;)Ljava/util/Set;
 }
 
+public final class com/gojek/courier/extensions/StringExtensionsKt {
+}
+
 public final class com/gojek/courier/extensions/TimeUnitExtensionsKt {
 }
 

courier-core/src/main/java/com/gojek/courier/extensions/StringExtensions.kt

@@ -0,0 +1,9 @@
+package com.gojek.courier.extensions
+
+import androidx.annotation.RestrictTo
+
+@RestrictTo(RestrictTo.Scope.LIBRARY)
+fun String.isWildCardTopic(): Boolean {
+    return startsWith("+/") || contains("/+/") || endsWith("/+") || equals("+") ||
+        endsWith("/#") || equals("#")
+}

courier/src/main/java/com/gojek/courier/coordinator/Coordinator.kt

@@ -16,10 +16,14 @@ import com.gojek.mqtt.client.model.ConnectionState
 import com.gojek.mqtt.client.model.MqttMessage
 import com.gojek.mqtt.event.EventHandler
 import com.gojek.mqtt.event.MqttEvent
+import com.gojek.mqtt.event.MqttEvent.MqttSubscribeFailureEvent
 import io.reactivex.BackpressureStrategy
 import io.reactivex.Flowable
 import io.reactivex.FlowableOnSubscribe
+import io.reactivex.disposables.CompositeDisposable
 import io.reactivex.schedulers.Schedulers
+import io.reactivex.subjects.PublishSubject
+import org.eclipse.paho.client.mqttv3.MqttException
 import org.reactivestreams.Subscriber
 import org.reactivestreams.Subscription
 
@@ -28,6 +32,18 @@ internal class Coordinator(
     private val logger: ILogger
 ) : StubInterface.Callback {
 
+    private val eventSubject = PublishSubject.create<MqttEvent> { emitter ->
+        val eventHandler = object : EventHandler {
+            override fun onEvent(mqttEvent: MqttEvent) {
+                if (emitter.isDisposed.not()) {
+                    emitter.onNext(mqttEvent)
+                }
+            }
+        }
+        client.addEventHandler(eventHandler)
+        emitter.setCancellable { client.removeEventHandler(eventHandler) }
+    }
+
     @Synchronized
     override fun send(stubMethod: StubMethod.Send, args: Array<Any>): Any {
         logger.d("Coordinator", "Send method invoked")
@@ -106,7 +122,15 @@ internal class Coordinator(
                     }
                 }
                 client.addMessageListener(topic, listener)
-                emitter.setCancellable { client.removeMessageListener(topic, listener) }
+                val eventDisposable = eventSubject.filter { event ->
+                    isInvalidSubscriptionFailureEvent(event, topic)
+                }.subscribe {
+                    client.removeMessageListener(topic, listener)
+                }
+                emitter.setCancellable {
+                    client.removeMessageListener(topic, listener)
+                    eventDisposable.dispose()
+                }
             },
             BackpressureStrategy.BUFFER
         )
@@ -166,9 +190,22 @@ internal class Coordinator(
                         }
                     }
                 }
+                val eventDisposable = CompositeDisposable()
                 for (topic in topicList) {
                     client.addMessageListener(topic.first, listener)
-                    emitter.setCancellable { client.removeMessageListener(topic.first, listener) }
+                    eventDisposable.add(
+                        eventSubject.filter { event ->
+                            isInvalidSubscriptionFailureEvent(event, topic.first)
+                        }.subscribe {
+                            client.removeMessageListener(topic.first, listener)
+                        }
+                    )
+                }
+                emitter.setCancellable {
+                    for (topic in topicList) {
+                        client.removeMessageListener(topic.first, listener)
+                        eventDisposable.dispose()
+                    }
                 }
             },
             BackpressureStrategy.BUFFER
@@ -249,4 +286,10 @@ internal class Coordinator(
             null
         }
     }
+
+    private fun isInvalidSubscriptionFailureEvent(event: MqttEvent, topic: String): Boolean {
+        return event is MqttSubscribeFailureEvent &&
+            event.topics.containsKey(topic) &&
+            event.exception.reasonCode == MqttException.REASON_CODE_INVALID_SUBSCRIPTION.toInt()
+    }
 }

mqtt-client/src/main/java/com/gojek/mqtt/client/IncomingMsgControllerImpl.kt

@@ -1,6 +1,7 @@
 package com.gojek.mqtt.client
 
 import com.gojek.courier.extensions.fromSecondsToNanos
+import com.gojek.courier.extensions.isWildCardTopic
 import com.gojek.courier.logging.ILogger
 import com.gojek.courier.utils.Clock
 import com.gojek.mqtt.client.listener.MessageListener
@@ -47,6 +48,8 @@ internal class IncomingMsgControllerImpl(
 
     private val listenerMap = ConcurrentHashMap<String, List<MessageListener>>()
 
+    private val wildcardTopicListenerMap = ConcurrentHashMap<String, List<MessageListener>>()
+
     private var cleanupFuture: ScheduledFuture<*>? = null
 
     override fun triggerHandleMessage() {
@@ -64,40 +67,68 @@ internal class IncomingMsgControllerImpl(
 
     @Synchronized
     override fun registerListener(topic: String, listener: MessageListener) {
-        listenerMap[topic] = (listenerMap[topic] ?: emptyList()) + listener
+        if (topic.isWildCardTopic()) {
+            wildcardTopicListenerMap[topic] = (wildcardTopicListenerMap[topic] ?: emptyList()) + listener
+        } else {
+            listenerMap[topic] = (listenerMap[topic] ?: emptyList()) + listener
+        }
         triggerHandleMessage()
     }
 
     @Synchronized
     override fun unregisterListener(topic: String, listener: MessageListener) {
-        listenerMap[topic] = (listenerMap[topic] ?: emptyList()) - listener
-        if (listenerMap[topic]!!.isEmpty()) {
-            listenerMap.remove(topic)
+        if (topic.isWildCardTopic()) {
+            wildcardTopicListenerMap[topic] = (wildcardTopicListenerMap[topic] ?: emptyList()) - listener
+            if (wildcardTopicListenerMap[topic]!!.isEmpty()) {
+                wildcardTopicListenerMap.remove(topic)
+            }
+        } else {
+            listenerMap[topic] = (listenerMap[topic] ?: emptyList()) - listener
+            if (listenerMap[topic]!!.isEmpty()) {
+                listenerMap.remove(topic)
+            }
         }
     }
 
     private inner class HandleMessage : Runnable {
         override fun run() {
             try {
-                if (listenerMap.keys.isEmpty()) {
+                if (listenerMap.keys.isEmpty() && wildcardTopicListenerMap.isEmpty()) {
                     logger.d(TAG, "No listeners registered")
                     return
                 }
                 val messages: List<MqttReceivePacket> =
                     mqttReceivePersistence.getAllIncomingMessagesWithTopicFilter(listenerMap.keys)
-                if (mqttUtils.isEmpty(messages)) {
-                    logger.d(TAG, "No Messages in Table")
-                    return
-                }
                 val deletedMsgIds = mutableListOf<Long>()
                 for (message in messages) {
                     logger.d(TAG, "Going to process ${message.messageId}")
-                    val listenersNotified = notifyListeners(message)
+                    val listenersNotified = notifyListeners(message, listenerMap[message.topic]!!)
                     if (listenersNotified) {
                         deletedMsgIds.add(message.messageId)
                     }
                     logger.d(TAG, "Successfully Processed Message ${message.messageId}")
                 }
+                // processing messages for wildcard topic subscription
+                for (wildCardTopic in wildcardTopicListenerMap.keys()) {
+                    val topicForDBQuery = parseWildCardTopicForDBQuery(wildCardTopic)
+                    val wildcardMessages: List<MqttReceivePacket> =
+                        mqttReceivePersistence.getAllIncomingMessagesForWildCardTopic(topicForDBQuery)
+                    for (message in wildcardMessages) {
+                        logger.d(TAG, "Going to process ${message.messageId}")
+                        val wildCardTopicRegex = parseWildCardTopicForRegex(wildCardTopic)
+                        if (wildCardTopicRegex.matches(message.topic)) {
+                            logger.d(TAG, "Wildcard topic: $wildCardTopic matches ${message.topic}")
+                            val listenersNotified =
+                                notifyListeners(message, wildcardTopicListenerMap[wildCardTopic]!!)
+                            if (listenersNotified) {
+                                deletedMsgIds.add(message.messageId)
+                            }
+                        } else {
+                            logger.d(TAG, "Wildcard topic: $wildCardTopic does not match ${message.topic}")
+                        }
+                        logger.d(TAG, "Successfully Processed Message ${message.messageId}")
+                    }
+                }
                 if (deletedMsgIds.isNotEmpty()) {
                     val deletedMessagesCount = deleteMessages(deletedMsgIds)
                     logger.d(TAG, "Deleted $deletedMessagesCount messages")
@@ -112,6 +143,18 @@ internal class IncomingMsgControllerImpl(
         }
     }
 
+    private fun parseWildCardTopicForDBQuery(topic: String): String {
+        var updatedTopic: String = topic.replace("+", "%")
+        updatedTopic = updatedTopic.replace("#", "%")
+        return updatedTopic
+    }
+
+    private fun parseWildCardTopicForRegex(topic: String): Regex {
+        var updatedTopic: String = topic.replace("+", "[^\\/]+")
+        updatedTopic = updatedTopic.replace("#", "([^\\/]+(\\/?[^\\/])*)+")
+        return Regex(updatedTopic)
+    }
+
     private inner class CleanupExpiredMessages : Runnable {
         override fun run() {
             logger.d(TAG, "Deleting expired messages")
@@ -123,10 +166,10 @@ internal class IncomingMsgControllerImpl(
         }
     }
 
-    private fun notifyListeners(message: MqttReceivePacket): Boolean {
+    private fun notifyListeners(message: MqttReceivePacket, listeners: List<MessageListener>): Boolean {
         var notified = false
         try {
-            listenerMap[message.topic]!!.forEach {
+            listeners.forEach {
                 notified = true
                 it.onMessageReceived(message.toMqttMessage())
             }

mqtt-client/src/main/java/com/gojek/mqtt/connection/MqttConnection.kt

@@ -515,6 +515,7 @@ internal class MqttConnection(
                     ),
                     timeTakenMillis = (clock.nanoTime() - subscribeStartTime).fromNanosToMillis()
                 )
+                subscriptionStore.getListener().onInvalidTopicsSubscribeFailure(topicMap)
             }
         }
     }
@@ -546,6 +547,7 @@ internal class MqttConnection(
                     ),
                     timeTakenMillis = (clock.nanoTime() - unsubscribeStartTime).fromNanosToMillis()
                 )
+                subscriptionStore.getListener().onInvalidTopicsUnsubscribeFailure(topics)
             }
         }
     }
@@ -576,11 +578,12 @@ internal class MqttConnection(
                     connectionConfig.connectionEventHandler.onMqttSubscribeFailure(
                         topics = failTopicMap,
                         timeTakenMillis = (clock.nanoTime() - context.startTime).fromNanosToMillis(),
-                        throwable = MqttException(MqttException.REASON_CODE_INVALID_SUBSCRIPTION.toInt())
+                        throwable = MqttException(REASON_CODE_INVALID_SUBSCRIPTION.toInt())
                     )
                 }
 
                 subscriptionStore.getListener().onTopicsSubscribed(successTopicMap)
+                subscriptionStore.getListener().onInvalidTopicsSubscribeFailure(failTopicMap)
                 subscriptionPolicy.resetParams()
             }
 

mqtt-client/src/main/java/com/gojek/mqtt/persistence/IMqttReceivePersistence.kt

@@ -7,4 +7,5 @@ internal interface IMqttReceivePersistence {
     fun getAllIncomingMessagesWithTopicFilter(topics: Set<String>): List<MqttReceivePacket>
     fun removeReceivedMessages(messageIds: List<Long>): Int
     fun removeMessagesWithOlderTimestamp(timestampNanos: Long): Int
+    fun getAllIncomingMessagesForWildCardTopic(topic: String): List<MqttReceivePacket>
 }

mqtt-client/src/main/java/com/gojek/mqtt/persistence/dao/IncomingMessagesDao.kt

@@ -13,6 +13,9 @@ internal interface IncomingMessagesDao {
     @Query("SELECT * from incoming_messages where topic in (:topics)")
     fun getAllMessagesWithTopicFilter(topics: Set<String>): List<MqttReceivePacket>
 
+    @Query("SELECT * from incoming_messages where topic LIKE :topic")
+    fun getAllIncomingMessagesForWildCardTopic(topic: String): List<MqttReceivePacket>
+
     @Query("DELETE from incoming_messages")
     fun clearAllMessages()
 

mqtt-client/src/main/java/com/gojek/mqtt/persistence/impl/PahoPersistence.kt

@@ -86,6 +86,10 @@ internal class PahoPersistence(private val context: Context) :
         return incomingMessagesDao.getAllMessagesWithTopicFilter(topics)
     }
 
+    override fun getAllIncomingMessagesForWildCardTopic(topic: String): List<MqttReceivePacket> {
+        return incomingMessagesDao.getAllIncomingMessagesForWildCardTopic(topic)
+    }
+
     override fun removeReceivedMessages(messageIds: List<Long>): Int {
         return incomingMessagesDao.removeMessagesById(messageIds)
     }

mqtt-client/src/main/java/com/gojek/mqtt/subscription/InMemorySubscriptionStore.kt

@@ -4,7 +4,13 @@ import com.gojek.courier.QoS
 
 internal class InMemorySubscriptionStore : SubscriptionStore {
     private var state = State(mapOf())
-    private val listener = object : SubscriptionStoreListener {}
+    private val listener = object : SubscriptionStoreListener {
+        override fun onInvalidTopicsSubscribeFailure(topicMap: Map<String, QoS>) {
+            state = state.copy(
+                subscriptionTopics = state.subscriptionTopics - topicMap.keys
+            )
+        }
+    }
 
     private data class State(val subscriptionTopics: Map<String, QoS>)
 

mqtt-client/src/main/java/com/gojek/mqtt/subscription/PersistableSubscriptionStore.kt

@@ -15,6 +15,17 @@ internal class PersistableSubscriptionStore(context: Context) : SubscriptionStor
         override fun onTopicsUnsubscribed(topics: Set<String>) {
             onTopicsUnsubscribedInternal(topics)
         }
+
+        override fun onInvalidTopicsSubscribeFailure(topicMap: Map<String, QoS>) {
+            state = state.copy(
+                subscriptionTopics = state.subscriptionTopics - topicMap.keys,
+                pendingUnsubscribeTopics = state.pendingUnsubscribeTopics
+            )
+        }
+
+        override fun onInvalidTopicsUnsubscribeFailure(topics: Set<String>) {
+            onTopicsUnsubscribedInternal(topics)
+        }
     }
 
     private data class State(

mqtt-client/src/main/java/com/gojek/mqtt/subscription/PersistableSubscriptionStoreV2.kt

@@ -13,6 +13,17 @@ internal class PersistableSubscriptionStoreV2(context: Context) : SubscriptionSt
         override fun onTopicsUnsubscribed(topics: Set<String>) {
             onTopicsUnsubscribedInternal(topics)
         }
+
+        override fun onInvalidTopicsSubscribeFailure(topicMap: Map<String, QoS>) {
+            state = state.copy(
+                subscriptionTopics = state.subscriptionTopics - topicMap.keys,
+                pendingUnsubscribeTopics = state.pendingUnsubscribeTopics
+            )
+        }
+
+        override fun onInvalidTopicsUnsubscribeFailure(topics: Set<String>) {
+            onTopicsUnsubscribedInternal(topics)
+        }
     }
 
     private data class State(

mqtt-client/src/main/java/com/gojek/mqtt/subscription/SubscriptionStore.kt

@@ -13,5 +13,7 @@ internal interface SubscriptionStore {
 
 internal interface SubscriptionStoreListener {
     fun onTopicsSubscribed(topicMap: Map<String, QoS>) = Unit
+    fun onInvalidTopicsSubscribeFailure(topicMap: Map<String, QoS>) = Unit
     fun onTopicsUnsubscribed(topics: Set<String>) = Unit
+    fun onInvalidTopicsUnsubscribeFailure(topics: Set<String>) = Unit
 }