Add wcc in compute facade

Author: IoannisPanagiotas

algorithms-compute-facade/src/main/java/org/neo4j/gds/community/CommunityComputeFacade.java

@@ -34,7 +34,11 @@
 import org.neo4j.gds.conductance.Conductance;
 import org.neo4j.gds.conductance.ConductanceParameters;
 import org.neo4j.gds.conductance.ConductanceResult;
+import org.neo4j.gds.core.concurrency.Concurrency;
 import org.neo4j.gds.core.concurrency.DefaultPool;
+import org.neo4j.gds.core.concurrency.ParallelUtil;
+import org.neo4j.gds.core.utils.paged.dss.DisjointSetStruct;
+import org.neo4j.gds.core.utils.paged.dss.HugeAtomicDisjointSetStruct;
 import org.neo4j.gds.core.utils.progress.JobId;
 import org.neo4j.gds.hdbscan.HDBScan;
 import org.neo4j.gds.hdbscan.HDBScanParameters;
@@ -74,6 +78,8 @@
 import org.neo4j.gds.triangle.LocalClusteringCoefficientResult;
 import org.neo4j.gds.triangle.TriangleCountParameters;
 import org.neo4j.gds.triangle.TriangleCountResult;
+import org.neo4j.gds.wcc.Wcc;
+import org.neo4j.gds.wcc.WccParameters;
 
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
@@ -586,4 +592,37 @@ CompletableFuture<TimedAlgorithmResult<TriangleCountResult>> triangleCount(
         );
     }
 
+    CompletableFuture<TimedAlgorithmResult<DisjointSetStruct>> wcc(
+        Graph graph,
+        WccParameters parameters,
+        JobId jobId,
+        boolean logProgress
+    ) {
+
+        if (graph.isEmpty()) {
+            return CompletableFuture.completedFuture(TimedAlgorithmResult.empty( new HugeAtomicDisjointSetStruct(0 , new Concurrency(1))));
+        }
+
+        var progressTracker = progressTrackerFactory.create(
+            tasks.wcc(graph),
+            jobId,
+            parameters.concurrency(),
+            logProgress
+        );
+
+        var algorithm = new Wcc(
+            graph,
+            DefaultPool.INSTANCE,
+            ParallelUtil.DEFAULT_BATCH_SIZE,
+            parameters,
+            progressTracker,
+            terminationFlag
+        );
+
+        return algorithmCaller.run(
+            algorithm::compute,
+            jobId
+        );
+    }
+
 }

algorithms-compute-facade/src/test/java/org/neo4j/gds/community/CommunityComputeFacadeEmptyGraphTest.java

@@ -57,6 +57,7 @@
 import org.neo4j.gds.triangle.LocalClusteringCoefficientResult;
 import org.neo4j.gds.triangle.TriangleCountParameters;
 import org.neo4j.gds.triangle.TriangleCountResult;
+import org.neo4j.gds.wcc.WccParameters;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mock;
@@ -343,4 +344,21 @@ void triangleCount(){
         verifyNoInteractions(algorithmCallerMock);
     }
 
+    @Test
+    void wcc(){
+
+        var future = facade.wcc(
+            graph,
+            mock(WccParameters.class),
+            jobIdMock,
+            false
+        );
+
+        var results = future.join();
+
+        assertThat(results.result().size()).isEqualTo(0L);
+        verifyNoInteractions(progressTrackerFactoryMock);
+        verifyNoInteractions(algorithmCallerMock);
+    }
+
 }

algorithms-compute-facade/src/test/java/org/neo4j/gds/community/CommunityComputeFacadeTest.java

@@ -54,6 +54,7 @@
 import org.neo4j.gds.termination.TerminationFlag;
 import org.neo4j.gds.triangle.LocalClusteringCoefficientParameters;
 import org.neo4j.gds.triangle.TriangleCountParameters;
+import org.neo4j.gds.wcc.WccParameters;
 
 import java.util.List;
 import java.util.Optional;
@@ -414,4 +415,23 @@ void triangleCount(){
         assertThat(results.computeMillis()).isNotNegative();
     }
 
+    @Test
+    void wcc(){
+        var future = facade.wcc(
+            graph,
+            new WccParameters(
+                0,
+                null,
+                new Concurrency(4)
+            ),
+            jobIdMock,
+            false
+        );
+
+        var results = future.join();
+
+        assertThat(results.result().size()).isEqualTo(3L);
+        assertThat(results.computeMillis()).isNotNegative();
+    }
+
 }