ReduceVertexGroupItemBase.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.operators.grouping.functions;

import org.gradoop.common.model.impl.id.GradoopId;
import org.gradoop.flink.model.impl.operators.grouping.tuples.VertexGroupItem;
import org.gradoop.common.model.impl.properties.PropertyValueList;

/**
 * Base class for reducer/combiner implementations on vertices.
 */
abstract class ReduceVertexGroupItemBase extends BuildBase {
  /**
   * Reduce instantiations
   */
  private final VertexGroupItem reuseVertexGroupItem;

  /**
   * Creates build base.
   *
   * @param useLabel true, if element label shall be used for grouping
   */
  protected ReduceVertexGroupItemBase(boolean useLabel) {
    super(useLabel);
    this.reuseVertexGroupItem = new VertexGroupItem();
  }

  protected VertexGroupItem getReuseVertexGroupItem() {
    return this.reuseVertexGroupItem;
  }

  /**
   * Creates one super vertex tuple representing the whole group. This tuple is
   * later used to create a super vertex for each group.
   *
   * @param superVertexId super vertex id
   * @param groupLabel group label
   * @param groupPropertyValues group property values
   * @param aggregateValues aggregate values
   * @return vertex group item representing the super vertex
   */
  protected VertexGroupItem createSuperVertexTuple(
    GradoopId superVertexId, String groupLabel,
    PropertyValueList groupPropertyValues,
    PropertyValueList aggregateValues) {
    reuseVertexGroupItem.setVertexId(superVertexId);
    reuseVertexGroupItem.setGroupLabel(groupLabel);
    reuseVertexGroupItem.setGroupingValues(groupPropertyValues);
    reuseVertexGroupItem.setAggregateValues(aggregateValues);
    reuseVertexGroupItem.setSuperVertex(true);
    return reuseVertexGroupItem;
  }
}