ProjectEmbeddings.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.matching.single.cypher.operators.project;

import org.apache.flink.api.java.DataSet;
import org.gradoop.flink.model.impl.operators.matching.single.cypher.pojos.Embedding;
import org.gradoop.flink.model.impl.operators.matching.single.cypher.operators.PhysicalOperator;
import org.gradoop.flink.model.impl.operators.matching.single.cypher.operators.project.functions.ProjectEmbedding;

import java.util.List;
import java.util.stream.Collectors;

/**
 * Projects an Embedding by a set of properties.
 * For each entry in the embedding a different property set can be specified
 */
public class ProjectEmbeddings implements PhysicalOperator {
  /**
   * Input Embeddings
   */
  private final DataSet<Embedding> input;
  /**
   * Indices of all properties that will be kept in the projection
   */
  private final List<Integer> propertyWhiteList;

  /**
   * Operator name used for Flink operator description
   */
  private String name;

  /**
   * Creates a new embedding projection operator
   * @param input Embeddings that should be projected
   * @param propertyWhiteList property columns in the embedding that are taken over to the output
   */
  public ProjectEmbeddings(DataSet<Embedding> input, List<Integer> propertyWhiteList) {
    this.input = input;
    this.propertyWhiteList = propertyWhiteList.stream().sorted().collect(Collectors.toList());
    this.name = "ProjectEmbeddings";
  }

  @Override
  public DataSet<Embedding> evaluate() {
    return input
      .map(new ProjectEmbedding(propertyWhiteList))
      .name(getName());
  }

  @Override
  public void setName(String newName) {
    this.name = newName;
  }

  @Override
  public String getName() {
    return this.name;
  }
}