1 files changed, 205 insertions, 0 deletions
diff --git a/ms/blueprintsprocessor/modules/services/execution-service/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/services/execution/StreamingRemoteExecutionService.kt b/ms/blueprintsprocessor/modules/services/execution-service/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/services/execution/StreamingRemoteExecutionService.kt
new file mode 100644
index 000000000..adb1d67d2
--- /dev/null
+++ b/ms/blueprintsprocessor/modules/services/execution-service/src/main/kotlin/org/onap/ccsdk/cds/blueprintsprocessor/services/execution/StreamingRemoteExecutionService.kt
@@ -0,0 +1,205 @@
+/*
+ * Copyright © 2018-2019 AT&T Intellectual Property.
+ *
+ * Licensed 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, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onap.ccsdk.cds.blueprintsprocessor.services.execution
+
+import com.fasterxml.jackson.databind.JsonNode
+import com.github.marcoferrer.krotoplus.coroutines.client.ClientBidiCallChannel
+import com.github.marcoferrer.krotoplus.coroutines.client.clientCallBidiStreaming
+import io.grpc.ManagedChannel
+import kotlinx.coroutines.*
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.consumeAsFlow
+import org.onap.ccsdk.cds.blueprintsprocessor.grpc.GrpcClientProperties
+import org.onap.ccsdk.cds.blueprintsprocessor.grpc.service.BluePrintGrpcClientService
+import org.onap.ccsdk.cds.blueprintsprocessor.grpc.service.BluePrintGrpcLibPropertyService
+import org.onap.ccsdk.cds.controllerblueprints.common.api.EventType
+import org.onap.ccsdk.cds.controllerblueprints.core.BluePrintException
+import org.onap.ccsdk.cds.controllerblueprints.core.logger
+import org.onap.ccsdk.cds.controllerblueprints.processing.api.BluePrintProcessingServiceGrpc
+import org.onap.ccsdk.cds.controllerblueprints.processing.api.ExecutionServiceInput
+import org.onap.ccsdk.cds.controllerblueprints.processing.api.ExecutionServiceOutput
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty
+import org.springframework.stereotype.Service
+
+interface StreamingRemoteExecutionService<ReqT, ResT> {
+
+    suspend fun openSubscription(selector: Any, txId: String): Flow<ResT>
+
+    suspend fun sendNonInteractive(selector: Any, txId: String, input: ReqT, timeOutMill: Long): ResT
+
+    suspend fun send(txId: String, input: ReqT)
+
+    suspend fun cancelSubscription(txId: String)
+
+    suspend fun closeChannel(selector: Any)
+}
+
+@Service
+@ConditionalOnProperty(prefix = "blueprintsprocessor.streamingRemoteExecution", name = ["enabled"],
+        havingValue = "true", matchIfMissing = false)
+class StreamingRemoteExecutionServiceImpl(private val bluePrintGrpcLibPropertyService: BluePrintGrpcLibPropertyService)
+    : StreamingRemoteExecutionService<ExecutionServiceInput, ExecutionServiceOutput> {
+
+    private val log = logger(StreamingRemoteExecutionServiceImpl::class)
+
+    private val grpcChannels: MutableMap<String, ManagedChannel> = hashMapOf()
+
+    private val commChannels: MutableMap<String,
+            ClientBidiCallChannel<ExecutionServiceInput, ExecutionServiceOutput>> = hashMapOf()
+
+
+    /**
+     * Open new channel to send and receive for grpc properties [selector] for [txId],
+     * Create the only one GRPC channel per host port and reuse for further communication.
+     * Create request communication channel to send and receive requests and responses.
+     * We can send multiple request with same txId.
+     * Consume the flow for responses,
+     * Client should cancel the subscription for the request Id once no longer response is needed.
+     * */
+    @FlowPreview
+    override suspend fun openSubscription(selector: Any, txId: String): Flow<ExecutionServiceOutput> {
+
+        if (!commChannels.containsKey(txId)) {
+            /** Get GRPC Channel*/
+            val grpcChannel = grpcChannel(selector)
+
+            /** Get Send and Receive Channel for bidirectional process method*/
+            val channels = clientCallBidiStreaming(BluePrintProcessingServiceGrpc.getProcessMethod(), grpcChannel)
+            commChannels[txId] = channels
+        }
+
+        val commChannel = commChannels[txId]
+                ?: throw BluePrintException("failed to create response subscription for transactionId($txId) channel")
+
+        log.info("created subscription for transactionId($txId)")
+
+        return commChannel.responseChannel.consumeAsFlow()
+    }
+
+    /**
+     * Send the [input] request, by reusing same GRPC channel and Communication channel
+     * for the request Id.
+     */
+    override suspend fun send(txId: String, input: ExecutionServiceInput) {
+        val sendChannel = commChannels[txId]?.requestChannel
+                ?: throw BluePrintException("failed to get transactionId($txId) send channel")
+        coroutineScope {
+            launch {
+                sendChannel.send(input)
+                log.trace("Message sent for transactionId($txId)")
+            }
+        }
+    }
+
+    /**
+     * Simplified version of Streaming calls, Use this API only listing for actual response for [input]
+     * for the GRPC [selector] with execution [timeOutMill].
+     * Other state of the request will be skipped.
+     * The assumption here is you can call this API with same request Id and unique subrequest Id,
+     * so the correlation is sub request id to receive the response.
+     */
+    @ExperimentalCoroutinesApi
+    override suspend fun sendNonInteractive(selector: Any, txId: String, input: ExecutionServiceInput, timeOutMill: Long)
+            : ExecutionServiceOutput {
+
+        var output: ExecutionServiceOutput? = null
+        val flow = openSubscription(selector, txId)
+
+        /** Send the request */
+        val sendChannel = commChannels[txId]?.requestChannel
+                ?: throw BluePrintException("failed to get transactionId($txId) send channel")
+        sendChannel.send(input)
+
+        /** Receive the response with timeout */
+        withTimeout(timeOutMill) {
+            flow.collect {
+                log.trace("Received non-interactive transactionId($txId) response : ${it.status.eventType}")
+                if (it.status.eventType == EventType.EVENT_COMPONENT_EXECUTED) {
+                    output = it
+                    cancelSubscription(txId)
+                }
+            }
+        }
+        return output!!
+    }
+
+    /** Cancel the Subscription for the [txId], This closes communication channel **/
+    @ExperimentalCoroutinesApi
+    override suspend fun cancelSubscription(txId: String) {
+        commChannels[txId]?.let {
+            if (!it.requestChannel.isClosedForSend)
+                it.requestChannel.close()
+            /** If receive channel has to close immediately, once the subscription has cancelled, then enable this */
+            //it.responseChannel.cancel(CancellationException("subscription cancelled"))
+            commChannels.remove(txId)
+            log.info("closed subscription for transactionId($txId)")
+        }
+    }
+
+    /** Close the GRPC channel for the host port poperties [selector]*/
+    override suspend fun closeChannel(selector: Any) {
+        val grpcProperties = grpcProperties(selector)
+        val selectorName = "${grpcProperties.host}:${grpcProperties.port}"
+        if (grpcChannels.containsKey(selectorName)) {
+            grpcChannels[selectorName]!!.shutdownNow()
+            grpcChannels.remove(selectorName)
+            log.info("grpc channel($selectorName) shutdown completed")
+        }
+    }
+
+    /** Check GRPC channel has been cached and not shutdown, If not re create channel and chache it. */
+    private suspend fun grpcChannel(selector: Any): ManagedChannel {
+        val grpcProperties = grpcProperties(selector)
+        val selectorName = "${grpcProperties.host}:${grpcProperties.port}"
+        val isGrpcChannelCached = grpcChannels.containsKey(selectorName)
+        val grpcChannel = if (isGrpcChannelCached) {
+            if (grpcChannels[selectorName]!!.isShutdown) {
+                createGrpcChannel(grpcProperties)
+            } else {
+                grpcChannels[selectorName]!!
+            }
+        } else {
+            createGrpcChannel(grpcProperties)
+        }
+        grpcChannels[selectorName] = grpcChannel
+        return grpcChannel
+    }
+
+    suspend fun createGrpcChannel(grpcProperties: GrpcClientProperties): ManagedChannel {
+        val grpcClientService: BluePrintGrpcClientService = bluePrintGrpcLibPropertyService
+                .blueprintGrpcClientService(grpcProperties)
+        return grpcClientService.channel()
+    }
+
+    private fun grpcProperties(selector: Any): GrpcClientProperties {
+        return when (selector) {
+            is String -> {
+                bluePrintGrpcLibPropertyService.grpcClientProperties(selector.toString())
+            }
+            is JsonNode -> {
+                bluePrintGrpcLibPropertyService.grpcClientProperties(selector)
+            }
+            is GrpcClientProperties -> {
+                selector
+            }
+            else -> {
+                throw BluePrintException("couldn't process selector($selector)")
+            }
+        }
+    }
+}