LGraphToEPGMMapper.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.layouting.functions;
- import org.apache.flink.api.java.DataSet;
- import org.gradoop.common.model.impl.id.GradoopId;
- import org.gradoop.common.model.impl.pojo.EPGMEdge;
- import org.gradoop.common.model.impl.pojo.EPGMVertex;
- import org.gradoop.common.model.impl.properties.Properties;
- import org.gradoop.flink.model.impl.epgm.LogicalGraph;
- import org.gradoop.flink.model.impl.operators.layouting.FusingFRLayouter;
- import org.gradoop.flink.model.impl.operators.layouting.util.LEdge;
- import org.gradoop.flink.model.impl.operators.layouting.util.LGraph;
- import org.gradoop.flink.model.impl.operators.layouting.util.LVertex;
- import java.util.List;
- import java.util.stream.Collectors;
- /**
- * Converts an LGraph to an EPGM Graph
- */
- public class LGraphToEPGMMapper {
- /**
- * Build a new EPGM-Graph from the given LGraph, by converting LVertices to vertices 1:1.
- *
- * @param input The original EPGMGraph, to use it's factory
- * @param layouted The LGraph to convert
- * @return The converted LGraph
- */
- public LogicalGraph buildSimplifiedGraph(LogicalGraph input, LGraph layouted) {
- DataSet<EPGMVertex> vertices = layouted.getVertices().map(LGraphToEPGMMapper::mapTpEPGMVertex);
- DataSet<EPGMEdge> edges = layouted.getEdges().map(LGraphToEPGMMapper::mapToEPGMEdge);
- return input.getFactory().fromDataSets(vertices, edges);
- }
- /**
- * Map LVertex to EPGMVertex.
- *
- * @param lv Input LVertex
- * @return Output EPGMVertex
- */
- protected static EPGMVertex mapTpEPGMVertex(LVertex lv) {
- EPGMVertex v = new EPGMVertex(lv.getId(), "vertex", Properties.create(), null);
- lv.getPosition().setVertexPosition(v);
- v.setProperty(FusingFRLayouter.VERTEX_SIZE_PROPERTY, lv.getCount());
- v.setProperty(FusingFRLayouter.SUB_ELEMENTS_PROPERTY,
- getSubelementListValue(lv.getSubVertices()));
- return v;
- }
- /**
- * Map LEdge to EPGMEdge.
- *
- * @param le Input LEdge
- * @return Output EPGMEdge
- */
- protected static EPGMEdge mapToEPGMEdge(LEdge le) {
- EPGMEdge e = new EPGMEdge(le.getId(), "edge", le.getSourceId(), le.getTargetId(), Properties.create(),
- null);
- e.setProperty(FusingFRLayouter.VERTEX_SIZE_PROPERTY, le.getCount());
- e.setProperty(FusingFRLayouter.SUB_ELEMENTS_PROPERTY, getSubelementListValue(le.getSubEdges()));
- return e;
- }
- /**
- * Helper function to convert the List of sub-elements into a comma seperated string
- * Gradoop (especially the CSVDataSink) seems to have trouble with lists of PropertyValues, so
- * this is the easies workaround
- *
- * @param ids List of GradoopIds
- * @return A comma seperated string of ids
- */
- protected static String getSubelementListValue(List<GradoopId> ids) {
- return ids.stream().map(GradoopId::toString).collect(Collectors.joining(","));
- }
- }