ms/blueprintsprocessor/functions/message-prioritizaion/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/functions/message/prioritization/nats/NatsMessagePrioritizationConsumer.kt

   1 /*
   2  * Copyright © 2018-2019 AT&T Intellectual Property.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package org.onap.ccsdk.cds.blueprintsprocessor.functions.message.prioritization.nats
  18
  19 import io.nats.streaming.MessageHandler
  20 import io.nats.streaming.Subscription
  21 import kotlinx.coroutines.runBlocking
  22 import org.onap.ccsdk.cds.blueprintsprocessor.functions.message.prioritization.MessagePrioritizationService
  23 import org.onap.ccsdk.cds.blueprintsprocessor.functions.message.prioritization.db.MessagePrioritization
  24 import org.onap.ccsdk.cds.blueprintsprocessor.nats.asJsonType
  25 import org.onap.ccsdk.cds.blueprintsprocessor.nats.service.BluePrintNatsLibPropertyService
  26 import org.onap.ccsdk.cds.blueprintsprocessor.nats.service.BluePrintNatsService
  27 import org.onap.ccsdk.cds.blueprintsprocessor.nats.utils.NatsClusterUtils
  28 import org.onap.ccsdk.cds.blueprintsprocessor.nats.utils.SubscriptionOptionsUtils
  29 import org.onap.ccsdk.cds.controllerblueprints.core.BluePrintProcessorException
  30 import org.onap.ccsdk.cds.controllerblueprints.core.asType
  31 import org.onap.ccsdk.cds.controllerblueprints.core.logger
  32 import org.onap.ccsdk.cds.controllerblueprints.core.utils.ClusterUtils
  33
  34 open class NatsMessagePrioritizationConsumer(
  35     private val bluePrintNatsLibPropertyService: BluePrintNatsLibPropertyService,
  36     private val natsMessagePrioritizationService: MessagePrioritizationService
  37 ) {
  38     private val log = logger(NatsMessagePrioritizationConsumer::class)
  39
  40     lateinit var bluePrintNatsService: BluePrintNatsService
  41     private lateinit var subscription: Subscription
  42
  43     suspend fun startConsuming() {
  44         val prioritizationConfiguration = natsMessagePrioritizationService.getConfiguration()
  45         val natsConfiguration = prioritizationConfiguration.natsConfiguration
  46             ?: throw BluePrintProcessorException("couldn't get NATS consumer configuration")
  47
  48         check((natsMessagePrioritizationService is AbstractNatsMessagePrioritizationService)) {
  49             "messagePrioritizationService is not of type AbstractNatsMessagePrioritizationService."
  50         }
  51         bluePrintNatsService = consumerService(natsConfiguration.connectionSelector)
  52         natsMessagePrioritizationService.bluePrintNatsService = bluePrintNatsService
  53         val inputSubject = NatsClusterUtils.currentApplicationSubject(natsConfiguration.inputSubject)
  54         val loadBalanceGroup = ClusterUtils.applicationName()
  55         val messageHandler = createMessageHandler()
  56         val subscriptionOptions = SubscriptionOptionsUtils.durable(NatsClusterUtils.currentNodeDurable(inputSubject))
  57         subscription = bluePrintNatsService.loadBalanceSubscribe(
  58             inputSubject,
  59             loadBalanceGroup,
  60             messageHandler,
  61             subscriptionOptions
  62         )
  63         log.info(
  64             "Nats prioritization consumer listening on subject($inputSubject) on loadBalance group($loadBalanceGroup)."
  65         )
  66     }
  67
  68     suspend fun shutDown() {
  69         if (::subscription.isInitialized) {
  70             subscription.unsubscribe()
  71         }
  72         log.info("Nats prioritization consumer listener shutdown complete")
  73     }
  74
  75     private fun consumerService(selector: String): BluePrintNatsService {
  76         return bluePrintNatsLibPropertyService.bluePrintNatsService(selector)
  77     }
  78
  79     private fun createMessageHandler(): MessageHandler {
  80         return MessageHandler { message ->
  81             try {
  82                 val messagePrioritization = message.asJsonType().asType(MessagePrioritization::class.java)
  83                 runBlocking {
  84                     natsMessagePrioritizationService.prioritize(messagePrioritization)
  85                 }
  86             } catch (e: Exception) {
  87                 log.error("failed to process prioritize message", e)
  88             }
  89         }
  90     }
  91 }