feat(algorithm): add Degree graph algorithm for vertex in/out degree …

geaflow/geaflow-dsl/geaflow-dsl-plan/src/main/java/org/apache/geaflow/dsl/schema/function/BuildInSqlFunctionTable.java

@@ -37,6 +37,7 @@
 import org.apache.geaflow.dsl.udf.graph.AllSourceShortestPath;
 import org.apache.geaflow.dsl.udf.graph.ClosenessCentrality;
 import org.apache.geaflow.dsl.udf.graph.ClusterCoefficient;
+import org.apache.geaflow.dsl.udf.graph.Degree;
 import org.apache.geaflow.dsl.udf.graph.CommonNeighbors;
 import org.apache.geaflow.dsl.udf.graph.ConnectedComponents;
 import org.apache.geaflow.dsl.udf.graph.IncKHopAlgorithm;
@@ -251,6 +252,7 @@ public class BuildInSqlFunctionTable extends ListSqlOperatorTable {
             .add(GeaFlowFunction.of(LabelPropagation.class))
             .add(GeaFlowFunction.of(ConnectedComponents.class))
             .add(GeaFlowFunction.of(Louvain.class))
+            .add(GeaFlowFunction.of(Degree.class))
             .build();
 
     public BuildInSqlFunctionTable(GQLJavaTypeFactory typeFactory) {

geaflow/geaflow-dsl/geaflow-dsl-plan/src/main/java/org/apache/geaflow/dsl/udf/graph/Degree.java

@@ -0,0 +1,77 @@
+/*
+ * 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 org.apache.geaflow.dsl.udf.graph;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.Optional;
+import org.apache.geaflow.common.type.primitive.IntegerType;
+import org.apache.geaflow.dsl.common.algo.AlgorithmRuntimeContext;
+import org.apache.geaflow.dsl.common.algo.AlgorithmUserFunction;
+import org.apache.geaflow.dsl.common.data.Row;
+import org.apache.geaflow.dsl.common.data.RowEdge;
+import org.apache.geaflow.dsl.common.data.RowVertex;
+import org.apache.geaflow.dsl.common.data.impl.ObjectRow;
+import org.apache.geaflow.dsl.common.function.Description;
+import org.apache.geaflow.dsl.common.types.GraphSchema;
+import org.apache.geaflow.dsl.common.types.StructType;
+import org.apache.geaflow.dsl.common.types.TableField;
+import org.apache.geaflow.model.graph.edge.EdgeDirection;
+
+@Description(name = "degree", description = "built-in udga for Degree")
+public class Degree implements AlgorithmUserFunction<Object, Object> {
+
+    private AlgorithmRuntimeContext<Object, Object> context;
+
+    @Override
+    public void init(AlgorithmRuntimeContext<Object, Object> context, Object[] params) {
+        this.context = context;
+        if (params.length > 0) {
+            throw new IllegalArgumentException(
+                "Degree does not support any arguments, usage: func()");
+        }
+    }
+
+    @Override
+    public void process(RowVertex vertex, Optional<Row> updatedValues, Iterator<Object> messages) {
+        updatedValues.ifPresent(vertex::setValue);
+        int inDegree = this.context.loadEdges(EdgeDirection.IN).size();
+        int outDegree = this.context.loadEdges(EdgeDirection.OUT).size();
+        context.updateVertexValue(ObjectRow.create(inDegree, outDegree));
+    }
+
+    @Override
+    public void finish(RowVertex graphVertex, Optional<Row> updatedValues) {
+        updatedValues.ifPresent(graphVertex::setValue);
+        int inDegree = (int) graphVertex.getValue().getField(0, IntegerType.INSTANCE);
+        int outDegree = (int) graphVertex.getValue().getField(1, IntegerType.INSTANCE);
+        context.take(ObjectRow.create(graphVertex.getId(), inDegree, outDegree));
+    }
+
+    @Override
+    public StructType getOutputType(GraphSchema graphSchema) {
+        return new StructType(
+            new TableField("id", graphSchema.getIdType(), false),
+            new TableField("in_degree", IntegerType.INSTANCE, false),
+            new TableField("out_degree", IntegerType.INSTANCE, false)
+        );
+    }
+
+}

geaflow/geaflow-dsl/geaflow-dsl-runtime/src/test/java/org/apache/geaflow/dsl/runtime/query/GQLAlgorithmTest.java

@@ -363,6 +363,16 @@ public void testAlgorithmJaccardSimilarity() throws Exception {
             .checkSinkResult();
     }
 
+    @Test
+    public void testAlgorithmDegree() throws Exception {
+        QueryTester
+            .build()
+            .withGraphDefine("/query/modern_graph.sql")
+            .withQueryPath("/query/gql_algorithm_degree.sql")
+            .execute()
+            .checkSinkResult();
+    }
+
     @Test
     public void testEdgeIterator() throws Exception {
         QueryTester

geaflow/geaflow-dsl/geaflow-dsl-runtime/src/test/resources/expect/gql_algorithm_degree.txt

@@ -0,0 +1,6 @@
+1,0,3
+2,1,0
+3,3,0
+4,1,2
+5,1,0
+6,0,1

geaflow/geaflow-dsl/geaflow-dsl-runtime/src/test/resources/query/gql_algorithm_degree.sql

@@ -0,0 +1,28 @@
+/*
+ * 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.
+ */
+
+CREATE TABLE result_tb (vid int, in_degree int, out_degree int)
+  WITH (type='file', geaflow.dsl.file.path='${target}');
+
+USE GRAPH modern;
+
+INSERT INTO result_tb
+CALL degree() YIELD (vid, in_degree, out_degree)
+RETURN cast (vid as int), in_degree, out_degree
+;