org.gradoop.flink.algorithms.fsm.functions.SubgraphDecoder.java Source code

Introduction

Here is the source code for org.gradoop.flink.algorithms.fsm.functions.SubgraphDecoder.java

Source

/*
 * This file is part of Gradoop.
 *
 * Gradoop is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Gradoop is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Gradoop. If not, see <http://www.gnu.org/licenses/>.
 */

package org.gradoop.flink.algorithms.fsm.functions;

import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import org.apache.flink.api.common.functions.MapFunction;
import org.gradoop.common.model.impl.id.GradoopId;
import org.gradoop.common.model.impl.id.GradoopIdSet;
import org.gradoop.common.model.impl.pojo.Edge;
import org.gradoop.common.model.impl.pojo.EdgeFactory;
import org.gradoop.common.model.impl.pojo.GraphHead;
import org.gradoop.common.model.impl.pojo.GraphHeadFactory;
import org.gradoop.common.model.impl.pojo.Vertex;
import org.gradoop.common.model.impl.pojo.VertexFactory;
import org.gradoop.common.model.impl.properties.PropertyList;
import org.gradoop.flink.algorithms.fsm.pojos.FSMEdge;
import org.gradoop.flink.algorithms.fsm.tuples.Subgraph;
import org.gradoop.flink.model.impl.tuples.GraphTransaction;
import org.gradoop.flink.util.GradoopFlinkConfig;

import java.util.Collection;
import java.util.Map;
import java.util.Set;

/**
 * FSM subgraph -> Gradoop graph transaction.
 */
public class SubgraphDecoder implements MapFunction<Subgraph, GraphTransaction> {

    /**
     * Property key to store a frequent subgraphs's frequency.
     */
    public static final String FREQUENCY_KEY = "frequency";
    /**
     * Property key to store the canonical label.
     */
    public static final String CANONICAL_LABEL_KEY = "canonicalLabel";
    /**
     * Label of frequent subgraphs.
     */
    private static final String SUBGRAPH_LABEL = "FrequentSubgraph";
    /**
     * graph Head Factory
     */
    private final GraphHeadFactory graphHeadFactory;
    /**
     * vertex Factory
     */
    private final VertexFactory vertexFactory;
    /**
     * edge Factory
     */
    private final EdgeFactory edgeFactory;

    /**
     * Constructor.
     *
     * @param config Gradoop Flink configuration
     */
    public SubgraphDecoder(GradoopFlinkConfig config) {
        graphHeadFactory = config.getGraphHeadFactory();
        vertexFactory = config.getVertexFactory();
        edgeFactory = config.getEdgeFactory();
    }

    @Override
    public GraphTransaction map(Subgraph value) throws Exception {

        // GRAPH HEAD

        PropertyList properties = new PropertyList();

        properties.set(FREQUENCY_KEY, value.getCount());
        properties.set(CANONICAL_LABEL_KEY, value.getSubgraph());

        GraphHead epgmGraphHead = graphHeadFactory.createGraphHead(SUBGRAPH_LABEL, properties);

        GradoopIdSet graphIds = GradoopIdSet.fromExisting(epgmGraphHead.getId());

        // VERTICES

        Map<Integer, String> vertices = value.getEmbedding().getVertices();
        Set<Vertex> epgmVertices = Sets.newHashSetWithExpectedSize(vertices.size());
        Map<Integer, GradoopId> vertexIdMap = Maps.newHashMapWithExpectedSize(vertices.size());

        for (Map.Entry<Integer, String> vertex : vertices.entrySet()) {
            Vertex epgmVertex = vertexFactory.createVertex(vertex.getValue(), graphIds);

            vertexIdMap.put(vertex.getKey(), epgmVertex.getId());
            epgmVertices.add(epgmVertex);

        }

        // EDGES

        Collection<FSMEdge> edges = value.getEmbedding().getEdges().values();
        Set<Edge> epgmEdges = Sets.newHashSetWithExpectedSize(edges.size());

        for (FSMEdge edge : edges) {
            epgmEdges.add(edgeFactory.createEdge(edge.getLabel(), vertexIdMap.get(edge.getSourceId()),
                    vertexIdMap.get(edge.getTargetId()), graphIds));
        }

        return new GraphTransaction(epgmGraphHead, epgmVertices, epgmEdges);
    }
}