samoa-apex/src/main/java/org/apache/samoa/apex/topology/impl/ApexInputOperator.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.samoa.apex.topology.impl;

import java.io.Serializable;

import org.apache.samoa.core.ContentEvent;
import org.apache.samoa.core.EntranceProcessor;

import com.datatorrent.api.InputOperator;
import com.datatorrent.api.Context.OperatorContext;
import com.datatorrent.common.util.BaseOperator;
import com.esotericsoftware.kryo.DefaultSerializer;
import com.esotericsoftware.kryo.serializers.JavaSerializer;

/**
 * Apex Operator
 *
 */
@DefaultSerializer(JavaSerializer.class)
public class ApexInputOperator extends BaseOperator implements InputOperator, Serializable {

  private static final long DEFAULT_LIMIT = 2000;
  private long tuplesLimitPerWindow; // default
  private static final long serialVersionUID = 4255026962166445721L;
  private final EntranceProcessor entranceProcessor;
  private final DefaultOutputPortSerializable<ContentEvent> outputPort = new DefaultOutputPortSerializable<ContentEvent>();
  private transient int numTuples;

  public ApexInputOperator() {
    entranceProcessor = null;
  }

  ApexInputOperator(EntranceProcessor processor) {
    this.entranceProcessor = processor;
  }

  ApexStream createStream(String piId) {
    ApexStream stream = new ApexStream(piId);
    stream.outputPort = this.outputPort;
    return stream;
  }

  @Override
  public void setup(OperatorContext context) {
    this.entranceProcessor.onCreate(context.getId());
    if(tuplesLimitPerWindow == 0) {
      tuplesLimitPerWindow = DEFAULT_LIMIT;
    }
  }

  @Override
  public void beginWindow(long windowId) {
    super.beginWindow(windowId);
    numTuples = 0;
  }

  @Override
  public void emitTuples() {
    if (entranceProcessor.hasNext() && numTuples < tuplesLimitPerWindow) {
      outputPort.emit(entranceProcessor.nextEvent());
      numTuples++;
    }
  }

  public long getTuplesLimitPerWindow() {
    return tuplesLimitPerWindow;
  }

  public void setTuplesLimitPerWindow(long tuplesLimitPerWindow) {
    this.tuplesLimitPerWindow = tuplesLimitPerWindow;
  }
}