| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 com.datatorrent.contrib.nifi; |
| |
| import java.io.IOException; |
| import java.util.List; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import org.apache.apex.malhar.lib.wal.WindowDataManager; |
| import org.apache.nifi.remote.Transaction; |
| import org.apache.nifi.remote.TransferDirection; |
| import org.apache.nifi.remote.client.SiteToSiteClient; |
| |
| import com.datatorrent.api.Context; |
| import com.datatorrent.common.util.BaseOperator; |
| import com.datatorrent.netlet.util.DTThrowable; |
| |
| /** |
| * This is the base implementation of a NiFi output operator. |
| * A concrete operator should be created from this skeleton implementation. |
| * <p> |
| * <br> |
| * Ports:<br> |
| * <b>Input</b>: Can have any number of input ports<br> |
| * <b>Output</b>: no output port<br> |
| * <br> |
| * Properties:<br> |
| * None<br> |
| * <br> |
| * Compile time checks:<br> |
| * None<br> |
| * <br> |
| * Run time checks:<br> |
| * None<br> |
| * <br> |
| * Benchmarks:<br> |
| * TBD<br> |
| * <br> |
| * </p> |
| * |
| * @displayName Abstract NiFi Output |
| * @category Messaging |
| * @tags output operator |
| * |
| * |
| * @since 3.4.0 |
| */ |
| public abstract class AbstractNiFiOutputOperator<T> extends BaseOperator |
| { |
| |
| private static final Logger LOGGER = LoggerFactory.getLogger(AbstractNiFiOutputOperator.class); |
| |
| protected final SiteToSiteClient.Builder siteToSiteBuilder; |
| protected final NiFiDataPacketBuilder<T> dataPacketBuilder; |
| protected final WindowDataManager windowDataManager; |
| |
| protected transient SiteToSiteClient client; |
| |
| private transient int operatorContextId; |
| private transient long currentWindowId; |
| private transient long largestRecoveryWindowId; |
| protected transient boolean skipProcessingTuple = false; |
| |
| /** |
| * @param siteToSiteBuilder the builder for a NiFi SiteToSiteClient |
| * @param dataPacketBuilder a builder to produce NiFiDataPackets from incoming data |
| * @param windowDataManager a WindowDataManager to save and load state for windows of tuples |
| */ |
| public AbstractNiFiOutputOperator(final SiteToSiteClient.Builder siteToSiteBuilder, |
| final NiFiDataPacketBuilder<T> dataPacketBuilder, final WindowDataManager windowDataManager) |
| { |
| this.siteToSiteBuilder = siteToSiteBuilder; |
| this.dataPacketBuilder = dataPacketBuilder; |
| this.windowDataManager = windowDataManager; |
| } |
| |
| @Override |
| public void setup(Context.OperatorContext context) |
| { |
| this.client = siteToSiteBuilder.build(); |
| this.operatorContextId = context.getId(); |
| this.windowDataManager.setup(context); |
| } |
| |
| @Override |
| public void beginWindow(long windowId) |
| { |
| currentWindowId = windowId; |
| largestRecoveryWindowId = windowDataManager.getLargestCompletedWindow(); |
| |
| // if processing a window we've already seen, don't resend the tuples |
| if (currentWindowId <= largestRecoveryWindowId) { |
| skipProcessingTuple = true; |
| } else { |
| skipProcessingTuple = false; |
| } |
| } |
| |
| @Override |
| public void endWindow() |
| { |
| // if replaying then nothing to do |
| if (currentWindowId <= largestRecoveryWindowId) { |
| return; |
| } |
| |
| // if processing a new window then give sub-classes a chance to take action |
| endNewWindow(); |
| |
| // mark that we processed the window |
| try { |
| windowDataManager.save("processedWindow", currentWindowId); |
| } catch (IOException e) { |
| DTThrowable.rethrow(e); |
| } |
| } |
| |
| /** |
| * Called in endWindow() to give sub-classes a chance to take action when processing a new window. |
| * |
| * If the current window is <= the largest recovery window, this method will never be called. |
| */ |
| protected abstract void endNewWindow(); |
| |
| |
| @Override |
| public void teardown() |
| { |
| LOGGER.debug("Tearing down operator..."); |
| windowDataManager.teardown(); |
| try { |
| client.close(); |
| } catch (IOException e) { |
| DTThrowable.rethrow(e); |
| } |
| } |
| |
| /** |
| * Send the given batch of tuples to NiFi in a transaction, using the provided builder to |
| * first convert each tuple into a NiFiDataPacket. |
| * |
| * @param tuples a list of tuples to process |
| */ |
| protected void processTuples(List<T> tuples) |
| { |
| if (tuples == null || tuples.size() == 0) { |
| return; |
| } |
| |
| // create a transaction and send the data packets |
| try { |
| final Transaction transaction = client.createTransaction(TransferDirection.SEND); |
| if (transaction == null) { |
| throw new IllegalStateException("Unable to create a NiFi Transaction to send data"); |
| } |
| |
| // convert each tuple to a NiFiDataPacket using the provided builder |
| for (T tuple : tuples) { |
| NiFiDataPacket dp = dataPacketBuilder.createNiFiDataPacket(tuple); |
| transaction.send(dp.getContent(), dp.getAttributes()); |
| } |
| |
| transaction.confirm(); |
| transaction.complete(); |
| } catch (IOException ioe) { |
| DTThrowable.rethrow(ioe); |
| } |
| |
| } |
| |
| } |