metron-platform/metron-enrichment/metron-enrichment-storm/src/main/java/org/apache/metron/enrichment/bolt/SplitBolt.java

/**
 * 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 org.apache.metron.enrichment.bolt;

import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.metron.storm.common.bolt.ConfiguredEnrichmentBolt;
import org.apache.metron.common.performance.PerformanceLogger;
import org.apache.storm.task.OutputCollector;
import org.apache.storm.task.TopologyContext;
import org.apache.storm.topology.OutputFieldsDeclarer;
import org.apache.storm.tuple.Fields;
import org.apache.storm.tuple.Tuple;
import org.apache.storm.tuple.Values;

public abstract class SplitBolt<T extends Cloneable> extends ConfiguredEnrichmentBolt {
  public static class Perf {} // used for performance logging
  private PerformanceLogger perfLog; // not static bc multiple bolts may exist in same worker

  protected OutputCollector collector;

  public SplitBolt(String zookeeperUrl) {
    super(zookeeperUrl);
  }

  @Override
  public final void prepare(Map map, TopologyContext topologyContext,
                       OutputCollector outputCollector) {
    super.prepare(map, topologyContext, outputCollector);
    perfLog = new PerformanceLogger(() -> getConfigurations().getGlobalConfig(), Perf.class.getName());
    collector = outputCollector;
    prepare(map, topologyContext);
  }

  @Override
  public final void execute(Tuple tuple) {
    emit(tuple, generateMessage(tuple));
  }

  @Override
  public final void declareOutputFields(OutputFieldsDeclarer declarer) {
    declarer.declareStream("message", new Fields("key", "message", "subgroup"));
    for (String streamId : getStreamIds()) {
      declarer.declareStream(streamId, new Fields("key", "message"));
    }
    declarer.declareStream("error", new Fields("message"));
    declareOther(declarer);
  }

  public void emit(Tuple tuple, T message) {
    perfLog.mark("emit");
    if (message == null) return;
    String key = getKey(tuple, message);

    perfLog.mark("split-message");
    Map<String, List<T>> streamMessageMap = splitMessage(message);
    perfLog.log("split-message", "key={}, elapsed time to split message", key);

    for (String streamId : streamMessageMap.keySet()) {
      List<T> streamMessages = streamMessageMap.get(streamId);
      if (streamMessages != null) {
        for (T streamMessage : streamMessages) {
          if (streamMessage == null) {
            streamMessage = getDefaultMessage(streamId);
          }
          collector.emit(streamId, new Values(key, streamMessage));
        }
      } else {
        throw new IllegalArgumentException("Enrichment must send some list of messages, not null.");
      }
    }
    collector.emit("message", tuple, new Values(key, message, ""));
    collector.ack(tuple);
    emitOther(tuple, message);
    perfLog.log("emit", "key={}, elapsed time to run emit", key);
  }

  protected T getDefaultMessage(String streamId) {
    throw new IllegalArgumentException("Could not find a message for stream: " + streamId);
  }

  public abstract void prepare(Map map, TopologyContext topologyContext);

  public abstract Set<String> getStreamIds();

  public abstract String getKey(Tuple tuple, T message);

  public abstract T generateMessage(Tuple tuple);

  public abstract Map<String, List<T>> splitMessage(T message);

  public abstract void declareOther(OutputFieldsDeclarer declarer);

  public abstract void emitOther(Tuple tuple, T message);


}