static rule optimization by batching

packages/code-analyzer-sfge-engine/sfge/src/main/java/com/salesforce/rules/AbstractStaticRule.java

@@ -8,20 +8,41 @@
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 
 public abstract class AbstractStaticRule extends AbstractRule implements StaticRule {
+
     @Override
     public final List<Violation> run(GraphTraversalSource g) {
         return run(g, new ArrayList<>());
     }
 
+    /**
+     * TinkerGraph's .union() operator degrades non-linearly when given thousands of
+     * sub-traversals. Splitting targets into batches of this size keeps each .union()
+     * manageable and avoids the performance cliff.
+     */
+    private static final int BATCH_SIZE = 500;
+
     public final List<Violation> run(
             GraphTraversalSource g, List<AbstractRuleRunner.RuleRunnerTarget> targets) {
-        GraphTraversal<Vertex, Vertex> eligibleVertices = buildBaseTraversal(g, targets);
-        return _run(g, eligibleVertices);
-    }
+        if (targets.size() <= BATCH_SIZE) {
+            GraphTraversal<Vertex, Vertex> eligibleVertices =
+                    TraversalUtil.ruleTargetTraversal(g, targets);
+            return _run(g, eligibleVertices);
+        }
 
-    private GraphTraversal<Vertex, Vertex> buildBaseTraversal(
-            GraphTraversalSource g, List<AbstractRuleRunner.RuleRunnerTarget> targets) {
-        return TraversalUtil.ruleTargetTraversal(g, targets);
+        int totalBatches = (targets.size() + BATCH_SIZE - 1) / BATCH_SIZE;
+        List<Violation> allViolations = new ArrayList<>();
+
+        for (int batchNum = 0; batchNum < totalBatches; batchNum++) {
+            int fromIndex = batchNum * BATCH_SIZE;
+            int toIndex = Math.min(fromIndex + BATCH_SIZE, targets.size());
+            List<AbstractRuleRunner.RuleRunnerTarget> batch = targets.subList(fromIndex, toIndex);
+
+            GraphTraversal<Vertex, Vertex> batchTraversal =
+                    TraversalUtil.ruleTargetTraversal(g, batch);
+            List<Violation> batchViolations = _run(g, batchTraversal);
+            allViolations.addAll(batchViolations);
+        }
+        return allViolations;
     }
 
     /**