package com.thinkaurelius.faunus.mapreduce.filter;
import com.thinkaurelius.faunus.FaunusEdge;
import com.thinkaurelius.faunus.FaunusElement;
import com.thinkaurelius.faunus.FaunusVertex;
import com.thinkaurelius.faunus.Tokens;
import com.thinkaurelius.faunus.mapreduce.FaunusCompiler;
import com.thinkaurelius.faunus.mapreduce.util.EmptyConfiguration;
import com.tinkerpop.blueprints.Direction;
import com.tinkerpop.blueprints.Edge;
import com.tinkerpop.blueprints.Element;
import com.tinkerpop.blueprints.Vertex;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.mapreduce.Mapper;
import java.io.IOException;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
/**
* @author Marko A. Rodriguez (http://markorodriguez.com)
*/
public class CyclicPathFilterMap {
public static final String CLASS = Tokens.makeNamespace(CyclicPathFilterMap.class) + ".class";
public enum Counters {
PATHS_FILTERED
}
public static Configuration createConfiguration(final Class<? extends Element> klass) {
final Configuration configuration = new EmptyConfiguration();
configuration.setClass(CLASS, klass, Element.class);
configuration.setBoolean(FaunusCompiler.PATH_ENABLED, true);
return configuration;
}
public static class Map extends Mapper<NullWritable, FaunusVertex, NullWritable, FaunusVertex> {
private boolean isVertex;
private HashSet set = new HashSet();
@Override
public void setup(final Mapper.Context context) throws IOException, InterruptedException {
this.isVertex = context.getConfiguration().getClass(CLASS, Element.class, Element.class).equals(Vertex.class);
}
@Override
public void map(final NullWritable key, final FaunusVertex value, final Mapper<NullWritable, FaunusVertex, NullWritable, FaunusVertex>.Context context) throws IOException, InterruptedException {
long pathsFiltered = 0l;
if (this.isVertex) {
if (value.hasPaths()) {
final Iterator<List<FaunusElement.MicroElement>> itty = value.getPaths().iterator();
while (itty.hasNext()) {
final List<FaunusElement.MicroElement> path = itty.next();
this.set.clear();
this.set.addAll(path);
if (path.size() != this.set.size()) {
itty.remove();
pathsFiltered++;
}
}
}
} else {
for (final Edge e : value.getEdges(Direction.BOTH)) {
final FaunusEdge edge = (FaunusEdge) e;
if (edge.hasPaths()) {
final Iterator<List<FaunusElement.MicroElement>> itty = edge.getPaths().iterator();
while (itty.hasNext()) {
final List<FaunusElement.MicroElement> path = itty.next();
this.set.clear();
this.set.addAll(path);
if (path.size() != this.set.size()) {
itty.remove();
pathsFiltered++;
}
}
}
}
}
context.getCounter(Counters.PATHS_FILTERED).increment(pathsFiltered);
context.write(NullWritable.get(), value);
}
}
}