VertexFromId.java

/*
 * Copyright © 2014 - 2021 Leipzig University (Database Research Group)
 *
 * Licensed 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.gradoop.flink.model.impl.functions.epgm;

import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.functions.FunctionAnnotation;
import org.apache.flink.api.java.tuple.Tuple1;
import org.apache.flink.api.java.typeutils.ResultTypeQueryable;
import org.gradoop.common.model.api.entities.Vertex;
import org.gradoop.common.model.api.entities.VertexFactory;
import org.gradoop.common.model.impl.id.GradoopId;

/**
 * Initializes an {@link Vertex} from a given {@link GradoopId}.
 *
 * @param <V> The produced vertex type.
 */
@FunctionAnnotation.ForwardedFields("f0->id")
public class VertexFromId<V extends Vertex> implements
  MapFunction<Tuple1<GradoopId>, V>, ResultTypeQueryable<V> {

  /**
   * The type of the produced vertex.
   */
  private final TypeInformation<V> vertexType;

  /**
   * The factory used to create new vertices.
   */
  private final VertexFactory<V> vertexFactory;

  /**
   * Create new function.
   *
   * @param vertexFactory vertex factory
   */
  public VertexFromId(VertexFactory<V> vertexFactory) {
    this.vertexType = TypeInformation.of(vertexFactory.getType());
    this.vertexFactory = vertexFactory;
  }

  @Override
  public V map(Tuple1<GradoopId> gradoopId) throws Exception {
    return vertexFactory.initVertex(gradoopId.f0);
  }

  @Override
  public TypeInformation<V> getProducedType() {
    return vertexType;
  }
}