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Diffstat (limited to 'common/src/main/java/org/onap/so/client/cds/CDSProcessingClient.java')
| -rw-r--r-- | common/src/main/java/org/onap/so/client/cds/CDSProcessingClient.java | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/common/src/main/java/org/onap/so/client/cds/CDSProcessingClient.java b/common/src/main/java/org/onap/so/client/cds/CDSProcessingClient.java new file mode 100644 index 0000000000..0901cf589b --- /dev/null +++ b/common/src/main/java/org/onap/so/client/cds/CDSProcessingClient.java @@ -0,0 +1,112 @@ +/* + * Copyright (C) 2019 Bell Canada. + * + * 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.so.client.cds; + +import io.grpc.ManagedChannel; +import io.grpc.internal.DnsNameResolverProvider; +import io.grpc.internal.PickFirstLoadBalancerProvider; +import io.grpc.netty.NettyChannelBuilder; +import java.util.concurrent.CountDownLatch; +import org.onap.ccsdk.apps.controllerblueprints.processing.api.ExecutionServiceInput; +import org.onap.so.client.PreconditionFailedException; +import org.onap.so.client.RestPropertiesLoader; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * <p> + * The CDS processing client is using gRPC for communication between SO and CDS. + * That communication is configured to use a streaming approach, meaning that + * client can send an event to which server can reply will multiple sub-responses, + * until full completion of the processing. + * </p> + * <p> + * In order for the caller to manage the callback, it is the responsibility of the + * caller to implement and provide a {@link CDSProcessingListener} so received messages + * can be handled appropriately. + * </p> + * + * Here is an example of implementation of such listener: + * <pre> + * new CDSProcessingListener { + * + * @Override + * public void onMessage(ExecutionServiceOutput message) { + * log.info("Received notification from CDS: {}", message); + * } + * + * @Override + * public void onError(Throwable t) { + * Status status = Status.fromThrowable(t); + * log.error("Failed processing blueprint {}", status, t); + * } + * } + * </pre> + */ +public class CDSProcessingClient implements AutoCloseable { + + private static final Logger log = LoggerFactory.getLogger(CDSProcessingClient.class); + + private ManagedChannel channel; + private CDSProcessingHandler handler; + + public CDSProcessingClient(final CDSProcessingListener listener) { + CDSProperties props = RestPropertiesLoader.getInstance().getNewImpl(CDSProperties.class); + if (props == null) { + throw new PreconditionFailedException( + "No RestProperty.CDSProperties implementation found on classpath, can't create client."); + } + this.channel = NettyChannelBuilder + .forAddress(props.getHost(), props.getPort()) + .nameResolverFactory(new DnsNameResolverProvider()) + .loadBalancerFactory(new PickFirstLoadBalancerProvider()) + .usePlaintext() + .build(); + this.handler = new CDSProcessingHandler(listener); + log.info("CDSProcessingClient started"); + } + + CDSProcessingClient(final ManagedChannel channel, final CDSProcessingHandler handler) { + this.channel = channel; + this.handler = handler; + } + + /** + * Sends a request to the CDS backend micro-service. + * + * The caller will be returned a CountDownLatch that can be used + * to define how long the processing can wait. The CountDownLatch is + * initiated with just 1 count. When the client receives an #onCompleted callback, + * the counter will decrement. + * + * It is the user responsibility to close the client. + * + * @param input request to send + * @return CountDownLatch instance that can be use to #await for + * completeness of processing + */ + public CountDownLatch sendRequest(ExecutionServiceInput input) { + return handler.process(input, channel); + } + + @Override + public void close() { + if (channel != null) { + channel.shutdown(); + } + log.info("CDSProcessingClient stopped"); + } +}
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