diff --git a/gradoop-temporal/src/main/java/org/gradoop/temporal/model/impl/operators/metric/DegreeRangeEvolution.java b/gradoop-temporal/src/main/java/org/gradoop/temporal/model/impl/operators/metric/DegreeRangeEvolution.java new file mode 100644 index 000000000000..fa3fd5c3a69b --- /dev/null +++ b/gradoop-temporal/src/main/java/org/gradoop/temporal/model/impl/operators/metric/DegreeRangeEvolution.java @@ -0,0 +1,70 @@ +/* + * 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.temporal.model.impl.operators.metric; + +import org.apache.flink.api.java.DataSet; +import org.apache.flink.api.java.tuple.Tuple2; +import org.gradoop.flink.model.api.operators.UnaryBaseGraphToValueOperator; +import org.gradoop.flink.model.impl.operators.sampling.functions.VertexDegree; +import org.gradoop.temporal.model.api.TimeDimension; +import org.gradoop.temporal.model.impl.TemporalGraph; +import org.gradoop.temporal.model.impl.operators.metric.functions.GroupDegreeTreesToDegreeRange; +import org.gradoop.temporal.model.impl.operators.metric.functions.TransformDeltaToAbsoluteDegreeTree; +import org.gradoop.temporal.model.impl.operators.metric.functions.BuildTemporalDegreeTree; +import org.gradoop.temporal.model.impl.operators.metric.functions.FlatMapVertexIdEdgeInterval; + +import java.util.Objects; + +/** + * Operator that calculates the degree range evolution of a temporal graph for the + * whole lifetime of the graph. + */ +public class DegreeRangeEvolution implements UnaryBaseGraphToValueOperator>> { + /** + * The time dimension that will be considered. + */ + private final TimeDimension dimension; + + /** + * The degree type (IN, OUT, BOTH); + */ + private final VertexDegree degreeType; + + /** + * Creates an instance of this average degree evolution operator. + * + * @param degreeType the degree type to use (IN, OUT, BOTH). + * @param dimension the time dimension to use (VALID_TIME, TRANSACTION_TIME). + */ + public DegreeRangeEvolution(VertexDegree degreeType, TimeDimension dimension) { + this.degreeType = Objects.requireNonNull(degreeType); + this.dimension = Objects.requireNonNull(dimension); + } + + @Override + public DataSet> execute(TemporalGraph graph) { + return graph.getEdges() + // 1) Extract vertex id(s) and corresponding time intervals + .flatMap(new FlatMapVertexIdEdgeInterval(dimension, degreeType)) + // 2) Group them by the vertex id + .groupBy(0) + // 3) For each vertex id, build a degree tree data structure + .reduceGroup(new BuildTemporalDegreeTree()) + // 4) Transform each tree to aggregated evolution + .map(new TransformDeltaToAbsoluteDegreeTree()) + .reduceGroup(new GroupDegreeTreesToDegreeRange()); + } +} diff --git a/gradoop-temporal/src/main/java/org/gradoop/temporal/model/impl/operators/metric/functions/GroupDegreeTreesToDegreeRange.java b/gradoop-temporal/src/main/java/org/gradoop/temporal/model/impl/operators/metric/functions/GroupDegreeTreesToDegreeRange.java new file mode 100644 index 000000000000..ba8bc2b7ebb9 --- /dev/null +++ b/gradoop-temporal/src/main/java/org/gradoop/temporal/model/impl/operators/metric/functions/GroupDegreeTreesToDegreeRange.java @@ -0,0 +1,91 @@ +/* + * 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.temporal.model.impl.operators.metric.functions; + +import org.apache.flink.api.common.functions.GroupReduceFunction; +import org.apache.flink.api.java.tuple.Tuple2; +import org.apache.flink.util.Collector; +import org.gradoop.common.model.impl.id.GradoopId; + +import java.util.TreeMap; +import java.util.SortedSet; +import java.util.TreeSet; +import java.util.HashMap; +import java.util.Map; + +/** + * A group reduce function that merges all Tuples (vId, degreeTree) to a dataset of tuples (time, aggDegree) + * that represents the aggregated degree value for the whole graph at the given time. + */ +public class GroupDegreeTreesToDegreeRange + implements GroupReduceFunction>, Tuple2> { + + /** + * Creates an instance of this group reduce function. + * + */ + public GroupDegreeTreesToDegreeRange() { + + } + + @Override + public void reduce(Iterable>> iterable, + Collector> collector) throws Exception { + + // init necessary maps and set + HashMap> degreeTrees = new HashMap<>(); + HashMap vertexDegrees = new HashMap<>(); + SortedSet timePoints = new TreeSet<>(); + + // convert the iterables to a hashmap and remember all possible timestamps + for (Tuple2> tuple : iterable) { + degreeTrees.put(tuple.f0, tuple.f1); + timePoints.addAll(tuple.f1.keySet()); + } + + // Add default times + timePoints.add(Long.MIN_VALUE); + + for (Long timePoint : timePoints) { + // skip last default time + if (Long.MAX_VALUE == timePoint) { + continue; + } + // Iterate over all vertices + for (Map.Entry> entry : degreeTrees.entrySet()) { + // Make sure the vertex is registered in the current vertexDegrees capture + if (!vertexDegrees.containsKey(entry.getKey())) { + vertexDegrees.put(entry.getKey(), 0); + } + + // Check if timestamp is in tree, if not, take the lower key + if (entry.getValue().containsKey(timePoint)) { + vertexDegrees.put(entry.getKey(), entry.getValue().get(timePoint)); + } else { + Long lowerKey = entry.getValue().lowerKey(timePoint); + if (lowerKey != null) { + vertexDegrees.put(entry.getKey(), entry.getValue().get(lowerKey)); + } + } + } + + // Here, every tree with this time point is iterated. Now we need to aggregate for the current time. + int maxDegree = vertexDegrees.values().stream().reduce(Math::max).orElse(0); + int minDegree = vertexDegrees.values().stream().reduce(Math::min).orElse(0); + collector.collect(new Tuple2<>(timePoint, maxDegree - minDegree)); + } + } +} diff --git a/gradoop-temporal/src/main/java/org/gradoop/temporal/model/impl/operators/metric/functions/TransformDeltaToAbsoluteDegreeTree.java b/gradoop-temporal/src/main/java/org/gradoop/temporal/model/impl/operators/metric/functions/TransformDeltaToAbsoluteDegreeTree.java new file mode 100644 index 000000000000..719e76dcaccd --- /dev/null +++ b/gradoop-temporal/src/main/java/org/gradoop/temporal/model/impl/operators/metric/functions/TransformDeltaToAbsoluteDegreeTree.java @@ -0,0 +1,55 @@ +/* + * 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.temporal.model.impl.operators.metric.functions; + +import org.apache.flink.api.common.functions.MapFunction; +import org.apache.flink.api.java.functions.FunctionAnnotation; +import org.apache.flink.api.java.tuple.Tuple2; +import org.gradoop.common.model.impl.id.GradoopId; + +import java.util.Map; +import java.util.TreeMap; + +/** + * Replaces the degree tree, that just stores the degree changes for each time, with a degree tree that + * stores the actual degree of the vertex at that time. + */ +@FunctionAnnotation.ForwardedFields("f0") +public class TransformDeltaToAbsoluteDegreeTree + implements MapFunction>, + Tuple2>> { + + /** + * To reduce object instantiations. + */ + private TreeMap absoluteDegreeTree; + + @Override + public Tuple2> map( + Tuple2> vIdTreeMapTuple) throws Exception { + // init the degree and the temporal tree + int degree = 0; + absoluteDegreeTree = new TreeMap<>(); + + // aggregate the degrees + for (Map.Entry entry : vIdTreeMapTuple.f1.entrySet()) { + degree += entry.getValue(); + absoluteDegreeTree.put(entry.getKey(), degree); + } + vIdTreeMapTuple.f1 = absoluteDegreeTree; + return vIdTreeMapTuple; + } +} diff --git a/gradoop-temporal/src/test/java/org/gradoop/temporal/model/impl/operators/metric/DegreeRangeEvolutionTest.java b/gradoop-temporal/src/test/java/org/gradoop/temporal/model/impl/operators/metric/DegreeRangeEvolutionTest.java new file mode 100644 index 000000000000..bf831207a896 --- /dev/null +++ b/gradoop-temporal/src/test/java/org/gradoop/temporal/model/impl/operators/metric/DegreeRangeEvolutionTest.java @@ -0,0 +1,144 @@ +/* + * 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.temporal.model.impl.operators.metric; + +import org.apache.flink.api.common.typeinfo.TypeHint; +import org.apache.flink.api.java.DataSet; +import org.apache.flink.api.java.io.LocalCollectionOutputFormat; +import org.apache.flink.api.java.tuple.Tuple2; +import org.gradoop.common.model.impl.id.GradoopId; +import org.gradoop.flink.model.impl.operators.sampling.functions.VertexDegree; +import org.gradoop.temporal.model.api.TimeDimension; +import org.gradoop.temporal.model.impl.TemporalGraph; +import org.gradoop.temporal.util.TemporalGradoopTestBase; +import org.junit.Before; +import org.junit.Test; +import org.junit.runner.RunWith; +import org.junit.runners.Parameterized; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collection; +import java.util.HashSet; +import java.util.List; + +import static org.junit.Assert.assertTrue; + +@RunWith(Parameterized.class) +public class DegreeRangeEvolutionTest extends TemporalGradoopTestBase { + /** + * The expected in-degrees for each vertex label. + */ + private static final List> EXPECTED_IN_DEGREES = new ArrayList<>(); + /** + * The expected out-degrees for each vertex label. + */ + private static final List> EXPECTED_OUT_DEGREES = new ArrayList<>(); + /** + * The expected degrees for each vertex label. + */ + private static final List> EXPECTED_BOTH_DEGREES = new ArrayList<>(); + + static { + // IN DEGREES + EXPECTED_IN_DEGREES.add(new Tuple2<>(Long.MIN_VALUE, 0)); + EXPECTED_IN_DEGREES.add(new Tuple2<>(0L, 1)); + EXPECTED_IN_DEGREES.add(new Tuple2<>(4L, 2)); + EXPECTED_IN_DEGREES.add(new Tuple2<>(5L, 1)); + EXPECTED_IN_DEGREES.add(new Tuple2<>(6L, 1)); + EXPECTED_IN_DEGREES.add(new Tuple2<>(7L, 1)); + + // OUT DEGREES + EXPECTED_OUT_DEGREES.add(new Tuple2<>(Long.MIN_VALUE, 0)); + EXPECTED_OUT_DEGREES.add(new Tuple2<>(0L, 1)); + EXPECTED_OUT_DEGREES.add(new Tuple2<>(4L, 2)); + EXPECTED_OUT_DEGREES.add(new Tuple2<>(5L, 1)); + EXPECTED_OUT_DEGREES.add(new Tuple2<>(6L, 1)); + EXPECTED_OUT_DEGREES.add(new Tuple2<>(7L, 1)); + + // DEGREES + EXPECTED_BOTH_DEGREES.add(new Tuple2<>(Long.MIN_VALUE, 0)); + EXPECTED_BOTH_DEGREES.add(new Tuple2<>(0L, 1)); + EXPECTED_BOTH_DEGREES.add(new Tuple2<>(4L, 2)); + EXPECTED_BOTH_DEGREES.add(new Tuple2<>(5L, 1)); + EXPECTED_BOTH_DEGREES.add(new Tuple2<>(6L, 2)); + EXPECTED_BOTH_DEGREES.add(new Tuple2<>(7L, 1)); + } + + /** + * The degree type to test. + */ + @Parameterized.Parameter(0) + public VertexDegree degreeType; + + /** + * The expected degree range evolution for the given type. + */ + @Parameterized.Parameter(1) + public List> expectedDegrees; + + /** + * The temporal graph to test the operator. + */ + TemporalGraph testGraph; + + /** + * The parameters to test the operator. + * + * @return three different vertex degree types with its corresponding expected degree evolution. + */ + @Parameterized.Parameters(name = "Test degree type {0}.") + public static Iterable parameters() { + return Arrays.asList( + new Object[]{VertexDegree.IN, EXPECTED_IN_DEGREES}, + new Object[]{VertexDegree.OUT, EXPECTED_OUT_DEGREES}, + new Object[]{VertexDegree.BOTH, EXPECTED_BOTH_DEGREES}); + } + + /** + * Set up the test graph and create the id-label mapping. + * + * @throws Exception in case of an error + */ + @Before + public void setUp() throws Exception { + testGraph = getTestGraphWithValues(); + Collection> idLabelCollection = new HashSet<>(); + testGraph.getVertices().map(v -> new Tuple2<>(v.getId(), v.getLabel())) + .returns(new TypeHint>() { + }).output(new LocalCollectionOutputFormat<>(idLabelCollection)); + getExecutionEnvironment().execute(); + } + + /** + * Test the degree range evolution operator. + * + * @throws Exception in case of an error. + */ + @Test + public void testDegreeRange() throws Exception { + Collection> resultCollection = new ArrayList<>(); + + final DataSet> resultDataSet = testGraph + .callForValue(new DegreeRangeEvolution(degreeType, TimeDimension.VALID_TIME)); + + resultDataSet.output(new LocalCollectionOutputFormat<>(resultCollection)); + getExecutionEnvironment().execute(); + + assertTrue(resultCollection.containsAll(expectedDegrees)); + assertTrue(expectedDegrees.containsAll(resultCollection)); + } +}