implement LPA algorithm

computer-algorithm/src/main/java/com/baidu/hugegraph/computer/algorithm/community/lpa/Lpa.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2017 HugeGraph Authors
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with this
+ * work for additional information regarding copyright ownership. The ASF
+ * licenses this file to You 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 com.baidu.hugegraph.computer.algorithm.community.lpa;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+
+import org.apache.commons.lang3.mutable.MutableInt;
+
+import com.baidu.hugegraph.computer.core.graph.id.Id;
+import com.baidu.hugegraph.computer.core.graph.vertex.Vertex;
+import com.baidu.hugegraph.computer.core.worker.Computation;
+import com.baidu.hugegraph.computer.core.worker.ComputationContext;
+
+public class Lpa implements Computation<Id> {
+
+ private final Random random = new Random();
+
+ @Override
+ public String name() {
+ return "lpa";
+ }
+
+ @Override
+ public String category() {
+ return "community";
+ }
+
+ @Override
+ public void compute0(ComputationContext context, Vertex vertex) {
+ Id value = vertex.id();
+ vertex.value(value);
+ vertex.inactivate();
+ context.sendMessageToAllEdges(vertex, value);
+ }
+
+ @Override
+ public void compute(ComputationContext context, Vertex vertex,
+ Iterator<Id> messages) {
+ Id label = this.voteLabel(messages);
+ Id value = vertex.value();
+ if (!value.equals(label)) {
+ vertex.value(label);
+ context.sendMessageToAllEdges(vertex, label);
+ }
+ vertex.inactivate();
+ }
+
+ private Id voteLabel(Iterator<Id> messages) {
+ // Calculate label frequency
+ Map<Id, MutableInt> labels = new HashMap<>();
+ while (messages.hasNext()) {
+ Id label = messages.next();
+ MutableInt labelCount = labels.get(label);
+ if (labelCount != null) {
+ labelCount.increment();
+ } else {
+ labels.put(label, new MutableInt(1));
+ }
+ }
+
+ // Calculate the labels with maximum frequency
+ List<Id> maxLabels = new ArrayList<>();
+ int maxFreq = 1;
+ for (Map.Entry<Id, MutableInt> e : labels.entrySet()) {
+ int value = e.getValue().intValue();
+ if (value > maxFreq) {
+ maxFreq = value;
+ maxLabels.clear();
+ }
+ if (value == maxFreq) {
+ maxLabels.add(e.getKey());
+ }
+ }
+
+ // Random choice
+ int selected = this.random.nextInt(maxLabels.size());
+ return maxLabels.get(selected);
+ }
+}

computer-algorithm/src/main/java/com/baidu/hugegraph/computer/algorithm/community/lpa/LpaParams.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2017 HugeGraph Authors
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with this
+ * work for additional information regarding copyright ownership. The ASF
+ * licenses this file to You 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 com.baidu.hugegraph.computer.algorithm.community.lpa;
+
+import java.util.Map;
+
+import com.baidu.hugegraph.computer.algorithm.AlgorithmParams;
+import com.baidu.hugegraph.computer.core.config.ComputerOptions;
+import com.baidu.hugegraph.computer.core.graph.id.BytesId;
+import com.baidu.hugegraph.computer.core.output.LimitedLogOutput;
+
+public class LpaParams implements AlgorithmParams {
+
+ @Override
+ public void setAlgorithmParameters(Map<String, String> params) {
+ this.setIfAbsent(params, ComputerOptions.WORKER_COMPUTATION_CLASS,
+ Lpa.class.getName());
+ this.setIfAbsent(params, ComputerOptions.ALGORITHM_RESULT_CLASS,
+ BytesId.class.getName());
+ this.setIfAbsent(params, ComputerOptions.ALGORITHM_MESSAGE_CLASS,
+ BytesId.class.getName());
+ this.setIfAbsent(params, ComputerOptions.OUTPUT_CLASS,
+ LimitedLogOutput.class.getName());
+ }
+}

computer-test/src/main/java/com/baidu/hugegraph/computer/algorithm/AlgorithmTestSuite.java

@@ -24,18 +24,20 @@
 import org.junit.runners.Suite;
 
 import com.baidu.hugegraph.computer.algorithm.centrality.degree.DegreeCentralityTest;
+import com.baidu.hugegraph.computer.algorithm.centrality.pagerank.PageRankTest;
+import com.baidu.hugegraph.computer.algorithm.community.lpa.LpaTest;
 import com.baidu.hugegraph.computer.algorithm.community.trianglecount.TriangleCountTest;
+import com.baidu.hugegraph.computer.algorithm.community.wcc.WccTest;
 import com.baidu.hugegraph.computer.algorithm.path.rings.RingsDetectionTest;
 import com.baidu.hugegraph.computer.algorithm.path.rings.RingsDetectionWithFilterTest;
-import com.baidu.hugegraph.computer.algorithm.centrality.pagerank.PageRankTest;
-import com.baidu.hugegraph.computer.algorithm.community.wcc.WccTest;
 import com.baidu.hugegraph.config.OptionSpace;
 
 @RunWith(Suite.class)
 @Suite.SuiteClasses({
  PageRankTest.class,
  DegreeCentralityTest.class,
  WccTest.class,
+ LpaTest.class,
  TriangleCountTest.class,
  RingsDetectionTest.class,
  RingsDetectionWithFilterTest.class

computer-test/src/main/java/com/baidu/hugegraph/computer/algorithm/community/lpa/LpaTest.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2017 HugeGraph Authors
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with this
+ * work for additional information regarding copyright ownership. The ASF
+ * licenses this file to You 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 com.baidu.hugegraph.computer.algorithm.community.lpa;
+
+import org.junit.Test;
+
+import com.baidu.hugegraph.computer.algorithm.AlgorithmTestBase;
+
+public class LpaTest extends AlgorithmTestBase {
+
+ @Test
+ public void testRunAlgorithm() throws InterruptedException {
+ runAlgorithm(LpaParams.class.getName());
+ }
+}