BuildIdWithCandidates.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.common.functions;
import org.apache.flink.api.java.functions.FunctionAnnotation;
import org.apache.flink.configuration.Configuration;
import org.gradoop.common.model.api.entities.Vertex;
import org.gradoop.common.model.impl.id.GradoopId;
import org.gradoop.flink.model.impl.operators.matching.common.matching.ElementMatcher;
import org.gradoop.flink.model.impl.operators.matching.common.tuples.IdWithCandidates;
import java.util.Collection;
import static org.gradoop.common.util.GradoopConstants.DEFAULT_VERTEX_LABEL;
/**
* Converts an EPGM vertex to a {@link IdWithCandidates} tuple.
* <p>
* {@code vertex -> (vertexId, vertexCandidates)}
* <p>
* Forwarded Fields:<br>
* {@code id->f0: vertex id}
*
* @param <V> EPGM vertex type
*/
@FunctionAnnotation.ForwardedFields("id->f0")
public class BuildIdWithCandidates<V extends Vertex> extends AbstractBuilder<V, IdWithCandidates<GradoopId>> {
/**
* serial version uid
*/
private static final long serialVersionUID = 42L;
/**
* Query vertices to match against.
*/
private transient Collection<org.gradoop.gdl.model.Vertex> queryVertices;
/**
* Number of vertices in the query graph
*/
private int vertexCount;
/**
* Reduce instantiations
*/
private final IdWithCandidates<GradoopId> reuseTuple;
/**
* Constructor
*
* @param query GDL query
*/
public BuildIdWithCandidates(String query) {
super(query);
reuseTuple = new IdWithCandidates<>();
}
@Override
public void open(Configuration parameters) throws Exception {
super.open(parameters);
queryVertices = getQueryHandler().getVertices();
vertexCount = queryVertices.size();
}
@Override
public IdWithCandidates<GradoopId> map(V v) throws Exception {
reuseTuple.setId(v.getId());
reuseTuple.setCandidates(getCandidates(vertexCount,
ElementMatcher.getMatches(v, queryVertices, DEFAULT_VERTEX_LABEL)));
return reuseTuple;
}
}