/*

  * 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.giraph.edge;

 import org.apache.giraph.conf.GiraphConfigurationSettable;

 import org.apache.hadoop.io.Writable;

 /**

  * Implementations of this interface can decide whether

  * we should create a vertex when it is not present in vertex input

  * but exists in edge input.

  *

  * @param <I> vertex id

  */

 public interface CreateSourceVertexCallback<I extends Writable>

     extends GiraphConfigurationSettable {

   /**

    * Should we create a vertex that doesn't exist in vertex input

    * but only exists in edge input

    * @param vertexId the id of vertex to be created

    * @return true if we should create a vertex

    */

   boolean shouldCreateSourceVertex(I vertexId);

 }