content: /*
   * 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.spark.graphx;
  
  import java.io.Serializable;
  
  /**
   * Represents a subset of the fields of an [[EdgeTriplet]] or [[EdgeContext]]. This allows the
   * system to populate only those fields for efficiency.
   */
  public class TripletFields implements Serializable {
  
    /** Indicates whether the source vertex attribute is included. */
    public final boolean useSrc;
  
    /** Indicates whether the destination vertex attribute is included. */
    public final boolean useDst;
  
    /** Indicates whether the edge attribute is included. */
    public final boolean useEdge;
  
    /** Constructs a default TripletFields in which all fields are included. */
    public TripletFields() {
      this(true, true, true);
    }
  
    public TripletFields(boolean useSrc, boolean useDst, boolean useEdge) {
      this.useSrc = useSrc;
      this.useDst = useDst;
      this.useEdge = useEdge;
    }
  
    /**
     * None of the triplet fields are exposed.
     */
    public static final TripletFields None = new TripletFields(false, false, false);
  
    /**
     * Expose only the edge field and not the source or destination field.
     */
    public static final TripletFields EdgeOnly = new TripletFields(false, false, true);
  
    /**
     * Expose the source and edge fields but not the destination field. (Same as Src)
     */
    public static final TripletFields Src = new TripletFields(true, false, true);
  
    /**
     * Expose the destination and edge fields but not the source field. (Same as Dst)
     */
    public static final TripletFields Dst = new TripletFields(false, true, true);
  
    /**
     * Expose all the fields (source, edge, and destination).
     */
    public static final TripletFields All = new TripletFields(true, true, true);
  }
  