Add scc in compute facade

Author: IoannisPanagiotas

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

@@ -30,6 +30,7 @@
 import org.neo4j.gds.cliqueCounting.CliqueCounting;
 import org.neo4j.gds.cliqueCounting.CliqueCountingResult;
 import org.neo4j.gds.cliquecounting.CliqueCountingParameters;
+import org.neo4j.gds.collections.ha.HugeLongArray;
 import org.neo4j.gds.conductance.Conductance;
 import org.neo4j.gds.conductance.ConductanceParameters;
 import org.neo4j.gds.conductance.ConductanceResult;
@@ -64,6 +65,8 @@
 import org.neo4j.gds.modularityoptimization.ModularityOptimizationParameters;
 import org.neo4j.gds.modularityoptimization.ModularityOptimizationResult;
 import org.neo4j.gds.result.TimedAlgorithmResult;
+import org.neo4j.gds.scc.Scc;
+import org.neo4j.gds.scc.SccParameters;
 import org.neo4j.gds.termination.TerminationFlag;
 import org.neo4j.gds.triangle.LocalClusteringCoefficient;
 import org.neo4j.gds.triangle.LocalClusteringCoefficientParameters;
@@ -516,4 +519,34 @@ CompletableFuture<TimedAlgorithmResult<ModularityOptimizationResult>> modularity
         );
     }
 
+    CompletableFuture<TimedAlgorithmResult<HugeLongArray>> scc(
+        Graph graph,
+        SccParameters parameters,
+        JobId jobId,
+        boolean logProgress
+    ) {
+
+        if (graph.isEmpty()) {
+            return CompletableFuture.completedFuture(TimedAlgorithmResult.empty(HugeLongArray.newArray(0)));
+        }
+
+        var progressTracker = progressTrackerFactory.create(
+            tasks.scc(graph),
+            jobId,
+            parameters.concurrency(),
+            logProgress
+        );
+
+        var algorithm = new Scc(
+            graph,
+            progressTracker,
+            terminationFlag
+        );
+
+        return algorithmCaller.run(
+            algorithm::compute,
+            jobId
+        );
+    }
+
 }

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

@@ -51,6 +51,7 @@
 import org.neo4j.gds.modularity.ModularityResult;
 import org.neo4j.gds.modularityoptimization.ModularityOptimizationParameters;
 import org.neo4j.gds.modularityoptimization.ModularityOptimizationResult;
+import org.neo4j.gds.scc.SccParameters;
 import org.neo4j.gds.termination.TerminationFlag;
 import org.neo4j.gds.triangle.LocalClusteringCoefficientParameters;
 import org.neo4j.gds.triangle.LocalClusteringCoefficientResult;
@@ -305,4 +306,21 @@ void modularityOptimization(){
         verifyNoInteractions(progressTrackerFactoryMock);
         verifyNoInteractions(algorithmCallerMock);
     }
+
+    @Test
+    void scc(){
+
+        var future = facade.scc(
+            graph,
+            mock(SccParameters.class),
+            jobIdMock,
+            false
+        );
+
+        var results = future.join();
+
+        assertThat(results.result().toArray()).hasSize(0);
+        verifyNoInteractions(progressTrackerFactoryMock);
+        verifyNoInteractions(algorithmCallerMock);
+    }
 }

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

@@ -50,6 +50,7 @@
 import org.neo4j.gds.louvain.LouvainParameters;
 import org.neo4j.gds.modularity.ModularityParameters;
 import org.neo4j.gds.modularityoptimization.ModularityOptimizationParameters;
+import org.neo4j.gds.scc.SccParameters;
 import org.neo4j.gds.termination.TerminationFlag;
 import org.neo4j.gds.triangle.LocalClusteringCoefficientParameters;
 
@@ -376,4 +377,21 @@ void modularityOptimization(){
         assertThat(results.computeMillis()).isNotNegative();
     }
 
+    @Test
+    void scc(){
+        var future = facade.scc(
+            graph,
+            new SccParameters(
+                new Concurrency(4)
+            ),
+            jobIdMock,
+            false
+        );
+
+        var results = future.join();
+
+        assertThat(results.result().toArray()).hasSize(3);
+        assertThat(results.computeMillis()).isNotNegative();
+    }
+
 }