NumericMessageProvider.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
 *
 *   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.streams.local.test.providers;

import org.apache.streams.core.StreamsDatum;
import org.apache.streams.core.StreamsProvider;
import org.apache.streams.core.StreamsResultSet;

import org.joda.time.DateTime;

import java.math.BigInteger;
import java.util.Queue;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;

/**
 * Test StreamsProvider that sends out StreamsDatums numbered from 0 to numMessages.
 */
public class NumericMessageProvider implements StreamsProvider {

  @Override
  public String getId() {
    return "NumericMessageProvider";
  }

  private static final int DEFAULT_BATCH_SIZE = 100;

  private int numMessages;
  private BlockingQueue<StreamsDatum> data;
  private volatile boolean complete = false;

  public NumericMessageProvider(int numMessages) {
    this.numMessages = numMessages;
  }

  @Override
  public void startStream() {
    this.data = constructQueue();
  }

  @Override
  public StreamsResultSet readCurrent() {
    int batchSize = 0;
    Queue<StreamsDatum> batch = new LinkedBlockingQueue<>();
    try {
      while (!this.data.isEmpty() && batchSize < DEFAULT_BATCH_SIZE) {
        batch.add(this.data.take());
        ++batchSize;
      }
    } catch (InterruptedException ie) {
      Thread.currentThread().interrupt();
    }
//        System.out.println("******************\n**\tBatchSize="+batch.size()+"\n******************");
    this.complete = batch.isEmpty() && this.data.isEmpty();
    return new StreamsResultSet(batch);
  }

  @Override
  public StreamsResultSet readNew(BigInteger sequence) {
    return new StreamsResultSet(constructQueue());
  }

  @Override
  public StreamsResultSet readRange(DateTime start, DateTime end) {
    return new StreamsResultSet(constructQueue());
  }

  @Override
  public boolean isRunning() {
    return !this.complete;
  }

  @Override
  public void prepare(Object configurationObject) {
    this.data = constructQueue();
  }

  @Override
  public void cleanUp() {

  }

  private BlockingQueue<StreamsDatum> constructQueue() {
    BlockingQueue<StreamsDatum> datums = new ArrayBlockingQueue<>(numMessages);
    for(int i=0;i<numMessages;i++) {
      datums.add(new StreamsDatum(i));
    }
    return datums;
  }
}