org.apache.flink.graph.library.clustering.directed.TriangleListing.Result Java Examples

@Test
public void testSimpleGraphSorted() throws Exception {
	DataSet<Result<IntValue>> tl = directedSimpleGraph
		.run(new TriangleListing<IntValue, NullValue, NullValue>()
			.setSortTriangleVertices(true));

	String expectedResult =
		"(0,1,2,41)\n" +
		"(1,2,3,22)";

	TestBaseUtils.compareResultAsText(tl.collect(), expectedResult);
}
 

@Test
public void testRMatGraph() throws Exception {
	DataSet<Result<LongValue>> tl = directedRMatGraph(10, 16)
		.run(new TriangleListing<LongValue, NullValue, NullValue>()
			.setSortTriangleVertices(true));

	Checksum checksum = new ChecksumHashCode<Result<LongValue>>()
		.run(tl)
		.execute();

	assertEquals(75049, checksum.getCount());
	assertEquals(0x000092399c79299eL, checksum.getChecksum());
}
 

@Test
public void testWithEmptyGraphWithoutVertices() throws Exception {
	DataSet<Result<LongValue>> tl = emptyGraphWithoutVertices
		.run(new TriangleListing<>());

	assertEquals(0, tl.collect().size());
}
 

@Test
public void testWithEmptyGraphWithVertices() throws Exception {
	DataSet<Result<LongValue>> tl = emptyGraphWithVertices
		.run(new TriangleListing<>());

	assertEquals(0, tl.collect().size());
}
 

@Test
public void testSimpleGraphPermuted() throws Exception {
	DataSet<Result<IntValue>> tl = directedSimpleGraph
		.run(new TriangleListing<IntValue, NullValue, NullValue>()
			.setPermuteResults(true));

	String expectedResult =
		// permutation of (0,1,2,41)
		"1st vertex ID: 0, 2nd vertex ID: 1, 3rd vertex ID: 2, edge directions: 0->1, 0->2, 1<-2\n" +
		"1st vertex ID: 0, 2nd vertex ID: 2, 3rd vertex ID: 1, edge directions: 0->2, 0->1, 2->1\n" +
		"1st vertex ID: 1, 2nd vertex ID: 0, 3rd vertex ID: 2, edge directions: 1<-0, 1<-2, 0->2\n" +
		"1st vertex ID: 1, 2nd vertex ID: 2, 3rd vertex ID: 0, edge directions: 1<-2, 1<-0, 2<-0\n" +
		"1st vertex ID: 2, 2nd vertex ID: 0, 3rd vertex ID: 1, edge directions: 2<-0, 2->1, 0->1\n" +
		"1st vertex ID: 2, 2nd vertex ID: 1, 3rd vertex ID: 0, edge directions: 2->1, 2<-0, 1<-0\n" +
		// permutation of (1,2,3,22)
		"1st vertex ID: 1, 2nd vertex ID: 2, 3rd vertex ID: 3, edge directions: 1<-2, 1<-3, 2->3\n" +
		"1st vertex ID: 1, 2nd vertex ID: 3, 3rd vertex ID: 2, edge directions: 1<-3, 1<-2, 3<-2\n" +
		"1st vertex ID: 2, 2nd vertex ID: 1, 3rd vertex ID: 3, edge directions: 2->1, 2->3, 1<-3\n" +
		"1st vertex ID: 2, 2nd vertex ID: 3, 3rd vertex ID: 1, edge directions: 2->3, 2->1, 3->1\n" +
		"1st vertex ID: 3, 2nd vertex ID: 1, 3rd vertex ID: 2, edge directions: 3->1, 3<-2, 1<-2\n" +
		"1st vertex ID: 3, 2nd vertex ID: 2, 3rd vertex ID: 1, edge directions: 3<-2, 3->1, 2->1";

	List<String> printableStrings = new ArrayList<>();

	for (Result<IntValue> result : tl.collect()) {
		printableStrings.add(result.toPrintableString());
	}

	TestBaseUtils.compareResultAsText(printableStrings, expectedResult);
}
 

@Test
public void testSimpleGraphSorted() throws Exception {
	DataSet<Result<IntValue>> tl = directedSimpleGraph
		.run(new TriangleListing<IntValue, NullValue, NullValue>()
			.setSortTriangleVertices(true));

	String expectedResult =
		"(0,1,2,41)\n" +
		"(1,2,3,22)";

	TestBaseUtils.compareResultAsText(tl.collect(), expectedResult);
}
 

@Override
public Result<T> map(Result<T> value)
		throws Exception {
	// by the triangle listing algorithm we know f1 < f2
	if (value.getVertexId0().compareTo(value.getVertexId1()) > 0) {
		byte bitmask = value.getBitmask().getValue();

		T tempVal = value.getVertexId0();
		value.setVertexId0(value.getVertexId1());

		if (tempVal.compareTo(value.getVertexId2()) < 0) {
			value.setVertexId1(tempVal);

			int f0f1 = ((bitmask & 0b100000) >>> 1) | ((bitmask & 0b010000) << 1);
			int f0f2 = (bitmask & 0b001100) >>> 2;
			int f1f2 = (bitmask & 0b000011) << 2;

			value.setBitmask((byte) (f0f1 | f0f2 | f1f2));
		} else {
			value.setVertexId1(value.getVertexId2());
			value.setVertexId2(tempVal);

			int f0f1 = (bitmask & 0b000011) << 4;
			int f0f2 = ((bitmask & 0b100000) >>> 3) | ((bitmask & 0b010000) >>> 1);
			int f1f2 = ((bitmask & 0b001000) >>> 3) | ((bitmask & 0b000100) >>> 1);

			value.setBitmask((byte) (f0f1 | f0f2 | f1f2));
		}
	}

	return value;
}
 

@Override
public Result<T> join(Tuple4<T, T, T, ByteValue> triplet, Tuple3<T, T, ByteValue> edge)
		throws Exception {
	output.setVertexId0(triplet.f0);
	output.setVertexId1(triplet.f1);
	output.setVertexId2(triplet.f2);
	output.setBitmask((byte) (triplet.f3.getValue() | edge.f2.getValue()));
	return output;
}
 

@Test
public void testRMatGraph() throws Exception {
	DataSet<Result<LongValue>> tl = directedRMatGraph(10, 16)
		.run(new TriangleListing<LongValue, NullValue, NullValue>()
			.setSortTriangleVertices(true));

	Checksum checksum = new ChecksumHashCode<Result<LongValue>>()
		.run(tl)
		.execute();

	assertEquals(75049, checksum.getCount());
	assertEquals(0x000092399c79299eL, checksum.getChecksum());
}
 

@Test
public void testWithEmptyGraphWithoutVertices() throws Exception {
	DataSet<Result<LongValue>> tl = emptyGraphWithoutVertices
		.run(new TriangleListing<>());

	assertEquals(0, tl.collect().size());
}
 

@Test
public void testWithEmptyGraphWithVertices() throws Exception {
	DataSet<Result<LongValue>> tl = emptyGraphWithVertices
		.run(new TriangleListing<>());

	assertEquals(0, tl.collect().size());
}
 

@Test
public void testSimpleGraphPermuted() throws Exception {
	DataSet<Result<IntValue>> tl = directedSimpleGraph
		.run(new TriangleListing<IntValue, NullValue, NullValue>()
			.setPermuteResults(true));

	String expectedResult =
		// permutation of (0,1,2,41)
		"1st vertex ID: 0, 2nd vertex ID: 1, 3rd vertex ID: 2, edge directions: 0->1, 0->2, 1<-2\n" +
		"1st vertex ID: 0, 2nd vertex ID: 2, 3rd vertex ID: 1, edge directions: 0->2, 0->1, 2->1\n" +
		"1st vertex ID: 1, 2nd vertex ID: 0, 3rd vertex ID: 2, edge directions: 1<-0, 1<-2, 0->2\n" +
		"1st vertex ID: 1, 2nd vertex ID: 2, 3rd vertex ID: 0, edge directions: 1<-2, 1<-0, 2<-0\n" +
		"1st vertex ID: 2, 2nd vertex ID: 0, 3rd vertex ID: 1, edge directions: 2<-0, 2->1, 0->1\n" +
		"1st vertex ID: 2, 2nd vertex ID: 1, 3rd vertex ID: 0, edge directions: 2->1, 2<-0, 1<-0\n" +
		// permutation of (1,2,3,22)
		"1st vertex ID: 1, 2nd vertex ID: 2, 3rd vertex ID: 3, edge directions: 1<-2, 1<-3, 2->3\n" +
		"1st vertex ID: 1, 2nd vertex ID: 3, 3rd vertex ID: 2, edge directions: 1<-3, 1<-2, 3<-2\n" +
		"1st vertex ID: 2, 2nd vertex ID: 1, 3rd vertex ID: 3, edge directions: 2->1, 2->3, 1<-3\n" +
		"1st vertex ID: 2, 2nd vertex ID: 3, 3rd vertex ID: 1, edge directions: 2->3, 2->1, 3->1\n" +
		"1st vertex ID: 3, 2nd vertex ID: 1, 3rd vertex ID: 2, edge directions: 3->1, 3<-2, 1<-2\n" +
		"1st vertex ID: 3, 2nd vertex ID: 2, 3rd vertex ID: 1, edge directions: 3<-2, 3->1, 2->1";

	List<String> printableStrings = new ArrayList<>();

	for (Result<IntValue> result : tl.collect()) {
		printableStrings.add(result.toPrintableString());
	}

	TestBaseUtils.compareResultAsText(printableStrings, expectedResult);
}
 

@Override
public Result<T> map(Result<T> value)
		throws Exception {
	// by the triangle listing algorithm we know f1 < f2
	if (value.getVertexId0().compareTo(value.getVertexId1()) > 0) {
		byte bitmask = value.getBitmask().getValue();

		T tempVal = value.getVertexId0();
		value.setVertexId0(value.getVertexId1());

		if (tempVal.compareTo(value.getVertexId2()) < 0) {
			value.setVertexId1(tempVal);

			int f0f1 = ((bitmask & 0b100000) >>> 1) | ((bitmask & 0b010000) << 1);
			int f0f2 = (bitmask & 0b001100) >>> 2;
			int f1f2 = (bitmask & 0b000011) << 2;

			value.setBitmask((byte) (f0f1 | f0f2 | f1f2));
		} else {
			value.setVertexId1(value.getVertexId2());
			value.setVertexId2(tempVal);

			int f0f1 = (bitmask & 0b000011) << 4;
			int f0f2 = ((bitmask & 0b100000) >>> 3) | ((bitmask & 0b010000) >>> 1);
			int f1f2 = ((bitmask & 0b001000) >>> 3) | ((bitmask & 0b000100) >>> 1);

			value.setBitmask((byte) (f0f1 | f0f2 | f1f2));
		}
	}

	return value;
}
 

@Override
public Result<T> join(Tuple4<T, T, T, ByteValue> triplet, Tuple3<T, T, ByteValue> edge)
		throws Exception {
	output.setVertexId0(triplet.f0);
	output.setVertexId1(triplet.f1);
	output.setVertexId2(triplet.f2);
	output.setBitmask((byte) (triplet.f3.getValue() | edge.f2.getValue()));
	return output;
}
 

@Test
public void testRMatGraph() throws Exception {
	DataSet<Result<LongValue>> tl = directedRMatGraph(10, 16)
		.run(new TriangleListing<LongValue, NullValue, NullValue>()
			.setSortTriangleVertices(true));

	Checksum checksum = new ChecksumHashCode<Result<LongValue>>()
		.run(tl)
		.execute();

	assertEquals(75049, checksum.getCount());
	assertEquals(0x000092399c79299eL, checksum.getChecksum());
}
 

@Test
public void testWithEmptyGraphWithoutVertices() throws Exception {
	DataSet<Result<LongValue>> tl = emptyGraphWithoutVertices
		.run(new TriangleListing<>());

	assertEquals(0, tl.collect().size());
}
 

@Test
public void testWithEmptyGraphWithVertices() throws Exception {
	DataSet<Result<LongValue>> tl = emptyGraphWithVertices
		.run(new TriangleListing<>());

	assertEquals(0, tl.collect().size());
}
 

@Test
public void testSimpleGraphPermuted() throws Exception {
	DataSet<Result<IntValue>> tl = directedSimpleGraph
		.run(new TriangleListing<IntValue, NullValue, NullValue>()
			.setPermuteResults(true));

	String expectedResult =
		// permutation of (0,1,2,41)
		"1st vertex ID: 0, 2nd vertex ID: 1, 3rd vertex ID: 2, edge directions: 0->1, 0->2, 1<-2\n" +
		"1st vertex ID: 0, 2nd vertex ID: 2, 3rd vertex ID: 1, edge directions: 0->2, 0->1, 2->1\n" +
		"1st vertex ID: 1, 2nd vertex ID: 0, 3rd vertex ID: 2, edge directions: 1<-0, 1<-2, 0->2\n" +
		"1st vertex ID: 1, 2nd vertex ID: 2, 3rd vertex ID: 0, edge directions: 1<-2, 1<-0, 2<-0\n" +
		"1st vertex ID: 2, 2nd vertex ID: 0, 3rd vertex ID: 1, edge directions: 2<-0, 2->1, 0->1\n" +
		"1st vertex ID: 2, 2nd vertex ID: 1, 3rd vertex ID: 0, edge directions: 2->1, 2<-0, 1<-0\n" +
		// permutation of (1,2,3,22)
		"1st vertex ID: 1, 2nd vertex ID: 2, 3rd vertex ID: 3, edge directions: 1<-2, 1<-3, 2->3\n" +
		"1st vertex ID: 1, 2nd vertex ID: 3, 3rd vertex ID: 2, edge directions: 1<-3, 1<-2, 3<-2\n" +
		"1st vertex ID: 2, 2nd vertex ID: 1, 3rd vertex ID: 3, edge directions: 2->1, 2->3, 1<-3\n" +
		"1st vertex ID: 2, 2nd vertex ID: 3, 3rd vertex ID: 1, edge directions: 2->3, 2->1, 3->1\n" +
		"1st vertex ID: 3, 2nd vertex ID: 1, 3rd vertex ID: 2, edge directions: 3->1, 3<-2, 1<-2\n" +
		"1st vertex ID: 3, 2nd vertex ID: 2, 3rd vertex ID: 1, edge directions: 3<-2, 3->1, 2->1";

	List<String> printableStrings = new ArrayList<>();

	for (Result<IntValue> result : tl.collect()) {
		printableStrings.add(result.toPrintableString());
	}

	TestBaseUtils.compareResultAsText(printableStrings, expectedResult);
}
 

@Test
public void testSimpleGraphSorted() throws Exception {
	DataSet<Result<IntValue>> tl = directedSimpleGraph
		.run(new TriangleListing<IntValue, NullValue, NullValue>()
			.setSortTriangleVertices(true));

	String expectedResult =
		"(0,1,2,41)\n" +
		"(1,2,3,22)";

	TestBaseUtils.compareResultAsText(tl.collect(), expectedResult);
}
 

@Override
public Result<T> map(Result<T> value)
		throws Exception {
	// by the triangle listing algorithm we know f1 < f2
	if (value.getVertexId0().compareTo(value.getVertexId1()) > 0) {
		byte bitmask = value.getBitmask().getValue();

		T tempVal = value.getVertexId0();
		value.setVertexId0(value.getVertexId1());

		if (tempVal.compareTo(value.getVertexId2()) < 0) {
			value.setVertexId1(tempVal);

			int f0f1 = ((bitmask & 0b100000) >>> 1) | ((bitmask & 0b010000) << 1);
			int f0f2 = (bitmask & 0b001100) >>> 2;
			int f1f2 = (bitmask & 0b000011) << 2;

			value.setBitmask((byte) (f0f1 | f0f2 | f1f2));
		} else {
			value.setVertexId1(value.getVertexId2());
			value.setVertexId2(tempVal);

			int f0f1 = (bitmask & 0b000011) << 4;
			int f0f2 = ((bitmask & 0b100000) >>> 3) | ((bitmask & 0b010000) >>> 1);
			int f1f2 = ((bitmask & 0b001000) >>> 3) | ((bitmask & 0b000100) >>> 1);

			value.setBitmask((byte) (f0f1 | f0f2 | f1f2));
		}
	}

	return value;
}
 

@Override
public Result<T> join(Tuple4<T, T, T, ByteValue> triplet, Tuple3<T, T, ByteValue> edge)
		throws Exception {
	output.setVertexId0(triplet.f0);
	output.setVertexId1(triplet.f1);
	output.setVertexId2(triplet.f2);
	output.setBitmask((byte) (triplet.f3.getValue() | edge.f2.getValue()));
	return output;
}
 

@Override
public DataSet<Result<K>> runInternal(Graph<K, VV, EV> input)
		throws Exception {
	// u, v, bitmask where u < v
	DataSet<Tuple3<K, K, ByteValue>> filteredByID = input
		.getEdges()
		.map(new OrderByID<>())
			.setParallelism(parallelism)
			.name("Order by ID")
		.groupBy(0, 1)
		.reduceGroup(new ReduceBitmask<>())
			.setParallelism(parallelism)
			.name("Flatten by ID");

	// u, v, (deg(u), deg(v))
	DataSet<Edge<K, Tuple3<EV, Degrees, Degrees>>> pairDegrees = input
		.run(new EdgeDegreesPair<K, VV, EV>()
			.setParallelism(parallelism));

	// u, v, bitmask where deg(u) < deg(v) or (deg(u) == deg(v) and u < v)
	DataSet<Tuple3<K, K, ByteValue>> filteredByDegree = pairDegrees
		.map(new OrderByDegree<>())
			.setParallelism(parallelism)
			.name("Order by degree")
		.groupBy(0, 1)
		.reduceGroup(new ReduceBitmask<>())
			.setParallelism(parallelism)
			.name("Flatten by degree");

	// u, v, w, bitmask where (u, v) and (u, w) are edges in graph
	DataSet<Tuple4<K, K, K, ByteValue>> triplets = filteredByDegree
		.groupBy(0)
		.sortGroup(1, Order.ASCENDING)
		.reduceGroup(new GenerateTriplets<>())
			.name("Generate triplets");

	// u, v, w, bitmask where (u, v), (u, w), and (v, w) are edges in graph
	DataSet<Result<K>> triangles = triplets
		.join(filteredByID, JoinOperatorBase.JoinHint.REPARTITION_HASH_SECOND)
		.where(1, 2)
		.equalTo(0, 1)
		.with(new ProjectTriangles<>())
			.name("Triangle listing");

	if (permuteResults) {
		triangles = triangles
			.flatMap(new PermuteResult<>())
				.name("Permute triangle vertices");
	} else if (sortTriangleVertices.get()) {
		triangles = triangles
			.map(new SortTriangleVertices<>())
				.name("Sort triangle vertices");
	}

	return triangles;
}
 

@Override
public void flatMap(Result<T> value, Collector<Result<T>> out)
		throws Exception {
	T tmp;

	int f0f1, f0f2, f1f2;

	byte bitmask = value.getBitmask().getValue();

	// 0, 1, 2
	out.collect(value);

	tmp = value.getVertexId0();
	value.setVertexId0(value.getVertexId1());
	value.setVertexId1(tmp);

	f0f1 = ((bitmask & 0b100000) >>> 1) | ((bitmask & 0b010000) << 1);
	f0f2 = (bitmask & 0b001100) >>> 2;
	f1f2 = (bitmask & 0b000011) << 2;

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 1, 0, 2
	out.collect(value);

	tmp = value.getVertexId1();
	value.setVertexId1(value.getVertexId2());
	value.setVertexId2(tmp);

	f0f1 = (bitmask & 0b110000) >>> 2;
	f0f2 = (bitmask & 0b001100) << 2;
	f1f2 = ((bitmask & 0b000010) >>> 1) | ((bitmask & 0b000001) << 1);

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 1, 2, 0
	out.collect(value);

	tmp = value.getVertexId0();
	value.setVertexId0(value.getVertexId2());
	value.setVertexId2(tmp);

	f0f1 = ((bitmask & 0b100000) >>> 5) | ((bitmask & 0b010000) >>> 3);
	f0f2 = ((bitmask & 0b001000) >>> 1) | ((bitmask & 0b000100) << 1);
	f1f2 = ((bitmask & 0b000010) << 3) | ((bitmask & 0b000001) << 5);

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 0, 2, 1
	out.collect(value);

	tmp = value.getVertexId0();
	value.setVertexId0(value.getVertexId1());
	value.setVertexId1(tmp);

	f0f1 = ((bitmask & 0b100000) >>> 1) | ((bitmask & 0b010000) << 1);
	f0f2 = (bitmask & 0b001100) >>> 2;
	f1f2 = (bitmask & 0b000011) << 2;

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 2, 0, 1
	out.collect(value);

	tmp = value.getVertexId1();
	value.setVertexId1(value.getVertexId2());
	value.setVertexId2(tmp);

	f0f1 = (bitmask & 0b110000) >>> 2;
	f0f2 = (bitmask & 0b001100) << 2;
	f1f2 = ((bitmask & 0b000010) >>> 1) | ((bitmask & 0b000001) << 1);

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 2, 1, 0
	out.collect(value);
}
 

@Override
public DataSet<Result<K>> runInternal(Graph<K, VV, EV> input)
		throws Exception {
	// u, v, bitmask where u < v
	DataSet<Tuple3<K, K, ByteValue>> filteredByID = input
		.getEdges()
		.map(new OrderByID<>())
			.setParallelism(parallelism)
			.name("Order by ID")
		.groupBy(0, 1)
		.reduceGroup(new ReduceBitmask<>())
			.setParallelism(parallelism)
			.name("Flatten by ID");

	// u, v, (deg(u), deg(v))
	DataSet<Edge<K, Tuple3<EV, Degrees, Degrees>>> pairDegrees = input
		.run(new EdgeDegreesPair<K, VV, EV>()
			.setParallelism(parallelism));

	// u, v, bitmask where deg(u) < deg(v) or (deg(u) == deg(v) and u < v)
	DataSet<Tuple3<K, K, ByteValue>> filteredByDegree = pairDegrees
		.map(new OrderByDegree<>())
			.setParallelism(parallelism)
			.name("Order by degree")
		.groupBy(0, 1)
		.reduceGroup(new ReduceBitmask<>())
			.setParallelism(parallelism)
			.name("Flatten by degree");

	// u, v, w, bitmask where (u, v) and (u, w) are edges in graph
	DataSet<Tuple4<K, K, K, ByteValue>> triplets = filteredByDegree
		.groupBy(0)
		.sortGroup(1, Order.ASCENDING)
		.reduceGroup(new GenerateTriplets<>())
			.name("Generate triplets");

	// u, v, w, bitmask where (u, v), (u, w), and (v, w) are edges in graph
	DataSet<Result<K>> triangles = triplets
		.join(filteredByID, JoinOperatorBase.JoinHint.REPARTITION_HASH_SECOND)
		.where(1, 2)
		.equalTo(0, 1)
		.with(new ProjectTriangles<>())
			.name("Triangle listing");

	if (permuteResults) {
		triangles = triangles
			.flatMap(new PermuteResult<>())
				.name("Permute triangle vertices");
	} else if (sortTriangleVertices.get()) {
		triangles = triangles
			.map(new SortTriangleVertices<>())
				.name("Sort triangle vertices");
	}

	return triangles;
}
 

@Override
public DataSet<Result<K>> runInternal(Graph<K, VV, EV> input)
		throws Exception {
	// u, v, bitmask where u < v
	DataSet<Tuple3<K, K, ByteValue>> filteredByID = input
		.getEdges()
		.map(new OrderByID<>())
			.setParallelism(parallelism)
			.name("Order by ID")
		.groupBy(0, 1)
		.reduceGroup(new ReduceBitmask<>())
			.setParallelism(parallelism)
			.name("Flatten by ID");

	// u, v, (deg(u), deg(v))
	DataSet<Edge<K, Tuple3<EV, Degrees, Degrees>>> pairDegrees = input
		.run(new EdgeDegreesPair<K, VV, EV>()
			.setParallelism(parallelism));

	// u, v, bitmask where deg(u) < deg(v) or (deg(u) == deg(v) and u < v)
	DataSet<Tuple3<K, K, ByteValue>> filteredByDegree = pairDegrees
		.map(new OrderByDegree<>())
			.setParallelism(parallelism)
			.name("Order by degree")
		.groupBy(0, 1)
		.reduceGroup(new ReduceBitmask<>())
			.setParallelism(parallelism)
			.name("Flatten by degree");

	// u, v, w, bitmask where (u, v) and (u, w) are edges in graph
	DataSet<Tuple4<K, K, K, ByteValue>> triplets = filteredByDegree
		.groupBy(0)
		.sortGroup(1, Order.ASCENDING)
		.reduceGroup(new GenerateTriplets<>())
			.name("Generate triplets");

	// u, v, w, bitmask where (u, v), (u, w), and (v, w) are edges in graph
	DataSet<Result<K>> triangles = triplets
		.join(filteredByID, JoinOperatorBase.JoinHint.REPARTITION_HASH_SECOND)
		.where(1, 2)
		.equalTo(0, 1)
		.with(new ProjectTriangles<>())
			.name("Triangle listing");

	if (permuteResults) {
		triangles = triangles
			.flatMap(new PermuteResult<>())
				.name("Permute triangle vertices");
	} else if (sortTriangleVertices.get()) {
		triangles = triangles
			.map(new SortTriangleVertices<>())
				.name("Sort triangle vertices");
	}

	return triangles;
}
 

@Override
public void flatMap(Result<T> value, Collector<Result<T>> out)
		throws Exception {
	T tmp;

	int f0f1, f0f2, f1f2;

	byte bitmask = value.getBitmask().getValue();

	// 0, 1, 2
	out.collect(value);

	tmp = value.getVertexId0();
	value.setVertexId0(value.getVertexId1());
	value.setVertexId1(tmp);

	f0f1 = ((bitmask & 0b100000) >>> 1) | ((bitmask & 0b010000) << 1);
	f0f2 = (bitmask & 0b001100) >>> 2;
	f1f2 = (bitmask & 0b000011) << 2;

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 1, 0, 2
	out.collect(value);

	tmp = value.getVertexId1();
	value.setVertexId1(value.getVertexId2());
	value.setVertexId2(tmp);

	f0f1 = (bitmask & 0b110000) >>> 2;
	f0f2 = (bitmask & 0b001100) << 2;
	f1f2 = ((bitmask & 0b000010) >>> 1) | ((bitmask & 0b000001) << 1);

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 1, 2, 0
	out.collect(value);

	tmp = value.getVertexId0();
	value.setVertexId0(value.getVertexId2());
	value.setVertexId2(tmp);

	f0f1 = ((bitmask & 0b100000) >>> 5) | ((bitmask & 0b010000) >>> 3);
	f0f2 = ((bitmask & 0b001000) >>> 1) | ((bitmask & 0b000100) << 1);
	f1f2 = ((bitmask & 0b000010) << 3) | ((bitmask & 0b000001) << 5);

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 0, 2, 1
	out.collect(value);

	tmp = value.getVertexId0();
	value.setVertexId0(value.getVertexId1());
	value.setVertexId1(tmp);

	f0f1 = ((bitmask & 0b100000) >>> 1) | ((bitmask & 0b010000) << 1);
	f0f2 = (bitmask & 0b001100) >>> 2;
	f1f2 = (bitmask & 0b000011) << 2;

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 2, 0, 1
	out.collect(value);

	tmp = value.getVertexId1();
	value.setVertexId1(value.getVertexId2());
	value.setVertexId2(tmp);

	f0f1 = (bitmask & 0b110000) >>> 2;
	f0f2 = (bitmask & 0b001100) << 2;
	f1f2 = ((bitmask & 0b000010) >>> 1) | ((bitmask & 0b000001) << 1);

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 2, 1, 0
	out.collect(value);
}
 

@Override
public void flatMap(Result<T> value, Collector<Result<T>> out)
		throws Exception {
	T tmp;

	int f0f1, f0f2, f1f2;

	byte bitmask = value.getBitmask().getValue();

	// 0, 1, 2
	out.collect(value);

	tmp = value.getVertexId0();
	value.setVertexId0(value.getVertexId1());
	value.setVertexId1(tmp);

	f0f1 = ((bitmask & 0b100000) >>> 1) | ((bitmask & 0b010000) << 1);
	f0f2 = (bitmask & 0b001100) >>> 2;
	f1f2 = (bitmask & 0b000011) << 2;

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 1, 0, 2
	out.collect(value);

	tmp = value.getVertexId1();
	value.setVertexId1(value.getVertexId2());
	value.setVertexId2(tmp);

	f0f1 = (bitmask & 0b110000) >>> 2;
	f0f2 = (bitmask & 0b001100) << 2;
	f1f2 = ((bitmask & 0b000010) >>> 1) | ((bitmask & 0b000001) << 1);

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 1, 2, 0
	out.collect(value);

	tmp = value.getVertexId0();
	value.setVertexId0(value.getVertexId2());
	value.setVertexId2(tmp);

	f0f1 = ((bitmask & 0b100000) >>> 5) | ((bitmask & 0b010000) >>> 3);
	f0f2 = ((bitmask & 0b001000) >>> 1) | ((bitmask & 0b000100) << 1);
	f1f2 = ((bitmask & 0b000010) << 3) | ((bitmask & 0b000001) << 5);

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 0, 2, 1
	out.collect(value);

	tmp = value.getVertexId0();
	value.setVertexId0(value.getVertexId1());
	value.setVertexId1(tmp);

	f0f1 = ((bitmask & 0b100000) >>> 1) | ((bitmask & 0b010000) << 1);
	f0f2 = (bitmask & 0b001100) >>> 2;
	f1f2 = (bitmask & 0b000011) << 2;

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 2, 0, 1
	out.collect(value);

	tmp = value.getVertexId1();
	value.setVertexId1(value.getVertexId2());
	value.setVertexId2(tmp);

	f0f1 = (bitmask & 0b110000) >>> 2;
	f0f2 = (bitmask & 0b001100) << 2;
	f1f2 = ((bitmask & 0b000010) >>> 1) | ((bitmask & 0b000001) << 1);

	bitmask = (byte) (f0f1 | f0f2 | f1f2);
	value.setBitmask(bitmask);

	// 2, 1, 0
	out.collect(value);
}