Move BellmanFordWriteStep to dedicated module

Author: vnickolov

applications/algorithms/path-finding/build.gradle

@@ -26,6 +26,7 @@ dependencies {
     implementation project(':metrics-api')
     implementation project(':path-finding-configs')
     implementation project(':path-finding-mutate-steps')
+    implementation project(':path-finding-write-steps')
     implementation project(':progress-tracking')
     implementation project(':string-formatting')
     implementation project(':termination')

applications/algorithms/path-finding/src/main/java/org/neo4j/gds/applications/algorithms/pathfinding/PathFindingAlgorithmsWriteModeBusinessFacade.java

@@ -36,6 +36,7 @@
 import org.neo4j.gds.kspanningtree.KSpanningTreeWriteConfig;
 import org.neo4j.gds.logging.Log;
 import org.neo4j.gds.mem.MemoryEstimation;
+import org.neo4j.gds.pathfinding.BellmanFordWriteStep;
 import org.neo4j.gds.paths.WritePathOptionsConfig;
 import org.neo4j.gds.paths.astar.config.ShortestPathAStarWriteConfig;
 import org.neo4j.gds.paths.bellmanford.AllShortestPathsBellmanFordWriteConfig;
@@ -103,7 +104,12 @@ public <RESULT> RESULT bellmanFord(
     ) {
         var writeStep = new BellmanFordWriteStep(
             writeRelationshipService,
-            configuration
+            configuration.writeRelationshipType(),
+            configuration.writeNegativeCycles(),
+            configuration.writeNodeIds(),
+            configuration.writeCosts(),
+            configuration::resolveResultStore,
+            configuration.jobId()
         );
 
         return runAlgorithmAndWrite(

applications/algorithms/path-finding/src/main/java/org/neo4j/gds/applications/algorithms/pathfinding/ShortestPathWriteStep.java

@@ -29,6 +29,7 @@
 import org.neo4j.gds.config.WriteRelationshipConfig;
 import org.neo4j.gds.core.utils.progress.JobId;
 import org.neo4j.gds.logging.Log;
+import org.neo4j.gds.pathfinding.PathFindingWriteRelationshipSpecification;
 import org.neo4j.gds.paths.WritePathOptionsConfig;
 import org.neo4j.gds.paths.dijkstra.PathFindingResult;
 

procedures/path-finding-write-steps/build.gradle

@@ -0,0 +1,28 @@
+apply plugin: 'java-library'
+
+description = 'Neo4j Graph Data Science :: Path Finding Write Steps'
+
+group = 'org.neo4j.gds'
+
+dependencies {
+
+    // Neo4j dependencies
+    compileOnly(neo4j.common) { transitive = false }
+    compileOnly(neo4j.values) { transitive = false }
+
+
+    // FIXME: we need `:algo` because the algorithm results are there,
+    //  extract them in a separate project and bring it instead
+    implementation project(':algo')
+
+    implementation project(':algorithms-machinery')
+
+    // FIXME: Massively annoying we need to bring this in because services use configs;
+    //  Also `ElementTypeValidator` is there even though it's not depending on any config 🤷
+    implementation project(':config-api')
+
+    implementation project(':core')
+    implementation project(':core-api')
+    implementation project(':logging')
+    implementation project(':string-formatting')
+}

…ms/pathfinding/BellmanFordWriteStep.java …ds/pathfinding/BellmanFordWriteStep.javaapplications/algorithms/path-finding/src/main/java/org/neo4j/gds/applications/algorithms/pathfinding/BellmanFordWriteStep.java renamed to procedures/path-finding-write-steps/src/main/java/org/neo4j/gds/pathfinding/BellmanFordWriteStep.java applications/algorithms/path-finding/src/main/java/org/neo4j/gds/applications/algorithms/pathfinding/BellmanFordWriteStep.java renamed to procedures/path-finding-write-steps/src/main/java/org/neo4j/gds/pathfinding/BellmanFordWriteStep.java

@@ -17,7 +17,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-package org.neo4j.gds.applications.algorithms.pathfinding;
+package org.neo4j.gds.pathfinding;
 
 import org.neo4j.gds.api.Graph;
 import org.neo4j.gds.api.GraphStore;
@@ -26,19 +26,36 @@
 import org.neo4j.gds.applications.algorithms.machinery.WriteStep;
 import org.neo4j.gds.applications.algorithms.metadata.RelationshipsWritten;
 import org.neo4j.gds.core.utils.progress.JobId;
-import org.neo4j.gds.paths.bellmanford.AllShortestPathsBellmanFordWriteConfig;
 import org.neo4j.gds.paths.bellmanford.BellmanFordResult;
 
-class BellmanFordWriteStep implements WriteStep<BellmanFordResult, RelationshipsWritten> {
+import java.util.Optional;
+import java.util.function.Function;
+
+public final class BellmanFordWriteStep implements WriteStep<BellmanFordResult, RelationshipsWritten> {
     private final WriteRelationshipService writeRelationshipService;
-    private final AllShortestPathsBellmanFordWriteConfig configuration;
+    private final String writeRelationshipType;
+    private final boolean writeNegativeCycles;
+    private final boolean writeNodeIds;
+    private final boolean writeCosts;
+    private final Function<ResultStore, Optional<ResultStore>> resultStoreResolver;
+    private final JobId jobId;
 
-    BellmanFordWriteStep(
+    public BellmanFordWriteStep(
         WriteRelationshipService writeRelationshipService,
-        AllShortestPathsBellmanFordWriteConfig configuration
+        String writeRelationshipType,
+        boolean writeNegativeCycles,
+        boolean writeNodeIds,
+        boolean writeCosts,
+        Function<ResultStore, Optional<ResultStore>> resultStoreResolver,
+        JobId jobId
     ) {
-        this.configuration = configuration;
         this.writeRelationshipService = writeRelationshipService;
+        this.writeRelationshipType = writeRelationshipType;
+        this.writeNegativeCycles = writeNegativeCycles;
+        this.writeNodeIds = writeNodeIds;
+        this.writeCosts = writeCosts;
+        this.resultStoreResolver = resultStoreResolver;
+        this.jobId = jobId;
     }
 
     @Override
@@ -49,31 +66,27 @@ public RelationshipsWritten execute(
         BellmanFordResult result,
         JobId jobId
     ) {
-
-        var writeNodeIds = configuration.writeNodeIds();
-        var writeCosts = configuration.writeCosts();
-
-        var specification = new PathFindingWriteRelationshipSpecification(graph,writeNodeIds,writeCosts);
+        var specification = new PathFindingWriteRelationshipSpecification(graph, writeNodeIds, writeCosts);
         var keys = specification.createKeys();
-        var types=  specification.createTypes();
+        var types = specification.createTypes();
 
         var paths = result.shortestPaths();
-        if (configuration.writeNegativeCycles() && result.containsNegativeCycle()) {
+        if (writeNegativeCycles && result.containsNegativeCycle()) {
             paths = result.negativeCycles();
         }
         try (
             var relationshipStream = paths.mapPaths(specification::createRelationship);
         ) {
 
             return writeRelationshipService.writeFromRelationshipStream(
-                configuration.writeRelationshipType(),
+                writeRelationshipType,
                 keys,
                 types,
                 relationshipStream,
                 graph,
                 "Write shortest Paths",
-                configuration.resolveResultStore(resultStore),
-                configuration.jobId()
+                resultStoreResolver.apply(resultStore),
+                this.jobId
             );
         }
     }

…ndingWriteRelationshipSpecification.java …ndingWriteRelationshipSpecification.javaapplications/algorithms/path-finding/src/main/java/org/neo4j/gds/applications/algorithms/pathfinding/PathFindingWriteRelationshipSpecification.java renamed to procedures/path-finding-write-steps/src/main/java/org/neo4j/gds/pathfinding/PathFindingWriteRelationshipSpecification.java applications/algorithms/path-finding/src/main/java/org/neo4j/gds/applications/algorithms/pathfinding/PathFindingWriteRelationshipSpecification.java renamed to procedures/path-finding-write-steps/src/main/java/org/neo4j/gds/pathfinding/PathFindingWriteRelationshipSpecification.java

@@ -17,7 +17,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-package org.neo4j.gds.applications.algorithms.pathfinding;
+package org.neo4j.gds.pathfinding;
 
 import org.neo4j.gds.api.ExportedRelationship;
 import org.neo4j.gds.api.IdMap;
@@ -28,12 +28,13 @@
 
 import java.util.List;
 
-import static org.neo4j.gds.paths.dijkstra.config.ShortestPathDijkstraWriteConfig.COSTS_KEY;
-import static org.neo4j.gds.paths.dijkstra.config.ShortestPathDijkstraWriteConfig.NODE_IDS_KEY;
-import static org.neo4j.gds.paths.dijkstra.config.ShortestPathDijkstraWriteConfig.TOTAL_COST_KEY;
-
 final class PathFindingWriteRelationshipSpecification {
 
+    private static final String TOTAL_COST_KEY = "totalCost";
+    private static final String NODE_IDS_KEY = "nodeIds";
+    private static final String COSTS_KEY = "costs";
+
+
     private final IdMap idMap;
     private final boolean writeNodeIds;
     private final boolean writeCosts;

settings.gradle

@@ -376,6 +376,9 @@ project(':path-finding-mutate-steps').projectDir = file('procedures/path-finding
 include('path-finding-params')
 project(':path-finding-params').projectDir = file('algo-params/path-finding-params')
 
+include 'path-finding-write-steps'
+project(':path-finding-write-steps').projectDir = file("procedures/path-finding-write-steps")
+
 include('node-embeddings-facade-api')
 project(':node-embeddings-facade-api').projectDir = file('procedures/facade-api/node-embeddings-facade-api')