common/src/main/java/org/apache/nemo/common/dag/Edge.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.nemo.common.dag;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.JsonNodeFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Serializable;

/**
 * Connects two vertices of a DAG.
 * This class can be extended for various DAG representations.
 *
 * @param <V> the vertex type.
 */
public class Edge<V extends Vertex> implements Serializable {
  private static final Logger LOG = LoggerFactory.getLogger(Edge.class.getName());

  private final String id;
  private final V src;
  private final V dst;

  /**
   * Constructor for Edge.
   *
   * @param id  ID of the edge.
   * @param src source vertex.
   * @param dst destination vertex.
   */
  public Edge(final String id, final V src, final V dst) {
    this.id = id;
    this.src = src;
    this.dst = dst;
  }

  /**
   * @return the ID of the edge.
   */
  public final String getId() {
    return id;
  }

  /**
   * @return the numeric ID of the edge. (for edge id "edge-2", this method returns 2)
   */
  public final Integer getNumericId() {
    return Integer.parseInt(id.replaceAll("[^\\d.]", ""));
  }

  /**
   * @return source vertex.
   */
  public final V getSrc() {
    return src;
  }

  /**
   * @return destination vertex.
   */
  public final V getDst() {
    return dst;
  }

  /**
   * @return JSON representation of additional properties
   */
  @SuppressWarnings("checkstyle:designforextension")
  public JsonNode getPropertiesAsJsonNode() {
    return JsonNodeFactory.instance.objectNode();
  }
}