samoa-api/src/main/java/org/apache/samoa/topology/ComponentFactory.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.topology;

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

/**
 * ComponentFactory interface. Provides platform specific components.
 */
public interface ComponentFactory {

  /**
   * Creates a platform specific processing item with the specified processor.
   * 
   * @param processor
   *          contains the logic for this processing item.
   * @return ProcessingItem
   */
  public ProcessingItem createPi(Processor processor);

  /**
   * Creates a platform specific processing item with the specified processor. Additionally sets the parallelism level.
   * 
   * @param processor
   *          contains the logic for this processing item.
   * @param parallelism
   *          defines the amount of instances of this processing item will be created.
   * @return ProcessingItem
   */
  public ProcessingItem createPi(Processor processor, int parallelism);

  /**
   * Creates a platform specific processing item with the specified processor that is the entrance point in the
   * topology. This processing item can either generate a stream of data or connect to an external stream of data.
   * 
   * @param entranceProcessor
   *          contains the logic for this processing item.
   * @return EntranceProcessingItem
   */
  public EntranceProcessingItem createEntrancePi(EntranceProcessor entranceProcessor);

  /**
   * Creates a platform specific stream.
   * 
   * @param sourcePi
   *          source processing item which will provide the events for this stream.
   * @return Stream
   */
  public Stream createStream(IProcessingItem sourcePi);

  /**
   * Creates a platform specific topology.
   * 
   * @param topoName
   *          Topology name.
   * @return Topology
   */
  public Topology createTopology(String topoName);
}