KaaEventFactory.java

/*
 * Copyright 2014 CyberVision, Inc.
 *
 * 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.kaaproject.kaa.server.flume.sink.hdfs;

import com.google.common.collect.Lists;

import org.apache.avro.io.BinaryDecoder;
import org.apache.avro.io.DecoderFactory;
import org.apache.avro.specific.SpecificDatumReader;
import org.apache.flume.Event;
import org.kaaproject.kaa.server.common.log.shared.avro.gen.RecordData;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

public class KaaEventFactory {

  private SpecificDatumReader<RecordData> avroReader;
  private BinaryDecoder decoder;
  private Map<KaaSinkKey, Map<String, String>> headersMap = new HashMap<>();

  public KaaEventFactory() {
    avroReader = new SpecificDatumReader<>(RecordData.class);
  }

  /**
   * Process incoming flume event.
   *
   * @param event the event for processing
   */
  public Map<KaaSinkKey, List<KaaRecordEvent>> processIncomingFlumeEvent(Event event)
      throws IOException {
    final Map<KaaSinkKey, List<KaaRecordEvent>> eventsMap = new LinkedHashMap<>();

    byte[] body = event.getBody();
    decoder = DecoderFactory.get().binaryDecoder(body, decoder);

    RecordData data = avroReader.read(null, decoder);
    KaaSinkKey sinkKey = new KaaSinkKey(data.getApplicationToken(), data.getSchemaVersion());
    Map<String, String> headers = headersMap.get(sinkKey);
    if (headers == null) {
      headers = new HashMap<>();
      sinkKey.updateHeaders(headers);
      headersMap.put(sinkKey, headers);
    }
    List<KaaRecordEvent> events = Lists.newArrayList();
    for (ByteBuffer eventData : data.getEventRecords()) {
      KaaRecordEvent kaaRecordEvent = new KaaRecordEvent(data.getRecordHeader(),
          headers, eventData.array());
      events.add(kaaRecordEvent);
    }
    eventsMap.put(sinkKey, events);
    return eventsMap;
  }

}