package com.thinkaurelius.faunus.mapreduce.sideeffect;
import com.thinkaurelius.faunus.FaunusEdge;
import com.thinkaurelius.faunus.FaunusVertex;
import com.thinkaurelius.faunus.Tokens;
import com.thinkaurelius.faunus.mapreduce.util.EmptyConfiguration;
import com.tinkerpop.blueprints.Direction;
import com.tinkerpop.blueprints.Edge;
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.Iterator;
/**
* @author Marko A. Rodriguez (http://markorodriguez.com)
*/
public class CommitEdgesMap {
public static final String ACTION = Tokens.makeNamespace(CommitEdgesMap.class) + ".action";
public enum Counters {
OUT_EDGES_DROPPED,
OUT_EDGES_KEPT,
IN_EDGES_DROPPED,
IN_EDGES_KEPT
}
public static Configuration createConfiguration(final Tokens.Action action) {
final Configuration configuration = new EmptyConfiguration();
configuration.set(ACTION, action.name());
return configuration;
}
public static class Map extends Mapper<NullWritable, FaunusVertex, NullWritable, FaunusVertex> {
private boolean drop;
@Override
public void setup(final Mapper.Context context) throws IOException, InterruptedException {
this.drop = Tokens.Action.valueOf(context.getConfiguration().get(ACTION)).equals(Tokens.Action.DROP);
}
@Override
public void map(final NullWritable key, final FaunusVertex value, final Mapper<NullWritable, FaunusVertex, NullWritable, FaunusVertex>.Context context) throws IOException, InterruptedException {
Iterator<Edge> itty = value.getEdges(Direction.IN).iterator();
long edgesKept = 0;
long edgesDropped = 0;
while (itty.hasNext()) {
if (this.drop) {
if ((((FaunusEdge) itty.next()).hasPaths())) {
itty.remove();
edgesDropped++;
} else
edgesKept++;
} else {
if (!(((FaunusEdge) itty.next()).hasPaths())) {
itty.remove();
edgesDropped++;
} else
edgesKept++;
}
}
context.getCounter(Counters.IN_EDGES_DROPPED).increment(edgesDropped);
context.getCounter(Counters.IN_EDGES_KEPT).increment(edgesKept);
///////////////////
itty = value.getEdges(Direction.OUT).iterator();
edgesKept = 0;
edgesDropped = 0;
while (itty.hasNext()) {
if (this.drop) {
if ((((FaunusEdge) itty.next()).hasPaths())) {
itty.remove();
edgesDropped++;
} else
edgesKept++;
} else {
if (!(((FaunusEdge) itty.next()).hasPaths())) {
itty.remove();
edgesDropped++;
} else
edgesKept++;
}
}
context.getCounter(Counters.OUT_EDGES_DROPPED).increment(edgesDropped);
context.getCounter(Counters.OUT_EDGES_KEPT).increment(edgesKept);
context.write(NullWritable.get(), value);
}
}
}