Make rule initialization static (#125590)

Author: idegtiarenko

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/analysis/Analyzer.java

@@ -98,7 +98,6 @@
 import org.elasticsearch.xpack.esql.rule.ParameterizedRule;
 import org.elasticsearch.xpack.esql.rule.ParameterizedRuleExecutor;
 import org.elasticsearch.xpack.esql.rule.Rule;
-import org.elasticsearch.xpack.esql.rule.RuleExecutor;
 import org.elasticsearch.xpack.esql.session.Configuration;
 import org.elasticsearch.xpack.esql.telemetry.FeatureMetric;
 import org.elasticsearch.xpack.esql.type.EsqlDataTypeConverter;
@@ -153,19 +152,18 @@ public class Analyzer extends ParameterizedRuleExecutor<LogicalPlan, AnalyzerCon
     public static final List<Attribute> NO_FIELDS = List.of(
         new ReferenceAttribute(Source.EMPTY, "<no-fields>", DataType.NULL, Nullability.TRUE, null, true)
     );
-    private static final Iterable<RuleExecutor.Batch<LogicalPlan>> rules;
 
-    static {
-        var init = new Batch<>(
+    private static final List<Batch<LogicalPlan>> RULES = List.of(
+        new Batch<>(
             "Initialize",
             Limiter.ONCE,
             new ResolveTable(),
             new ResolveEnrich(),
             new ResolveLookupTables(),
             new ResolveFunctions(),
             new ResolveForkFunctions()
-        );
-        var resolution = new Batch<>(
+        ),
+        new Batch<>(
             "Resolution",
             /*
              * ImplicitCasting must be before ResolveRefs. Because a reference is created for a Bucket in Aggregate's aggregates,
@@ -176,16 +174,9 @@ public class Analyzer extends ParameterizedRuleExecutor<LogicalPlan, AnalyzerCon
             new ImplicitForkCasting(),
             new ResolveRefs(),
             new ResolveUnionTypes()  // Must be after ResolveRefs, so union types can be found
-        );
-        var finish = new Batch<>(
-            "Finish Analysis",
-            Limiter.ONCE,
-            new AddImplicitLimit(),
-            new AddImplicitForkLimit(),
-            new UnionTypesCleanup()
-        );
-        rules = List.of(init, resolution, finish);
-    }
+        ),
+        new Batch<>("Finish Analysis", Limiter.ONCE, new AddImplicitLimit(), new AddImplicitForkLimit(), new UnionTypesCleanup())
+    );
 
     private final Verifier verifier;
 
@@ -208,8 +199,8 @@ public LogicalPlan verify(LogicalPlan plan, BitSet partialMetrics) {
     }
 
     @Override
-    protected Iterable<RuleExecutor.Batch<LogicalPlan>> batches() {
-        return rules;
+    protected List<Batch<LogicalPlan>> batches() {
+        return RULES;
     }
 
     private static class ResolveTable extends ParameterizedAnalyzerRule<UnresolvedRelation, AnalyzerContext> {

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/LocalLogicalPlanOptimizer.java

@@ -21,7 +21,7 @@
 import java.util.ArrayList;
 import java.util.List;
 
-import static java.util.Arrays.asList;
+import static org.elasticsearch.common.util.CollectionUtils.arrayAsArrayList;
 import static org.elasticsearch.xpack.esql.optimizer.LogicalPlanOptimizer.cleanup;
 import static org.elasticsearch.xpack.esql.optimizer.LogicalPlanOptimizer.operators;
 
@@ -33,30 +33,32 @@
  */
 public class LocalLogicalPlanOptimizer extends ParameterizedRuleExecutor<LogicalPlan, LocalLogicalOptimizerContext> {
 
+    private static final List<Batch<LogicalPlan>> RULES = replaceRules(
+        arrayAsArrayList(
+            new Batch<>(
+                "Local rewrite",
+                Limiter.ONCE,
+                new ReplaceTopNWithLimitAndSort(),
+                new ReplaceMissingFieldWithNull(),
+                new InferIsNotNull(),
+                new InferNonNullAggConstraint()
+            ),
+            operators(),
+            cleanup()
+        )
+    );
+
     public LocalLogicalPlanOptimizer(LocalLogicalOptimizerContext localLogicalOptimizerContext) {
         super(localLogicalOptimizerContext);
     }
 
     @Override
     protected List<Batch<LogicalPlan>> batches() {
-        var local = new Batch<>(
-            "Local rewrite",
-            Limiter.ONCE,
-            new ReplaceTopNWithLimitAndSort(),
-            new ReplaceMissingFieldWithNull(),
-            new InferIsNotNull(),
-            new InferNonNullAggConstraint()
-        );
-
-        var rules = new ArrayList<Batch<LogicalPlan>>();
-        rules.add(local);
-        // TODO: if the local rules haven't touched the tree, the rest of the rules can be skipped
-        rules.addAll(asList(operators(), cleanup()));
-        return replaceRules(rules);
+        return RULES;
     }
 
     @SuppressWarnings("unchecked")
-    private List<Batch<LogicalPlan>> replaceRules(List<Batch<LogicalPlan>> listOfRules) {
+    private static List<Batch<LogicalPlan>> replaceRules(List<Batch<LogicalPlan>> listOfRules) {
         List<Batch<LogicalPlan>> newBatches = new ArrayList<>(listOfRules.size());
         for (var batch : listOfRules) {
             var rules = batch.rules();

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/LocalPhysicalPlanOptimizer.java

@@ -26,14 +26,14 @@
 import java.util.Collection;
 import java.util.List;
 
-import static java.util.Arrays.asList;
-
 /**
  * Manages field extraction and pushing parts of the query into Lucene. (Query elements that are not pushed into Lucene are executed via
  * the compute engine)
  */
 public class LocalPhysicalPlanOptimizer extends ParameterizedRuleExecutor<PhysicalPlan, LocalPhysicalOptimizerContext> {
 
+    private static final List<Batch<PhysicalPlan>> RULES = rules(true);
+
     private final PhysicalVerifier verifier = PhysicalVerifier.INSTANCE;
 
     public LocalPhysicalPlanOptimizer(LocalPhysicalOptimizerContext context) {
@@ -54,13 +54,12 @@ PhysicalPlan verify(PhysicalPlan plan) {
 
     @Override
     protected List<Batch<PhysicalPlan>> batches() {
-        return rules(true);
+        return RULES;
     }
 
-    protected List<Batch<PhysicalPlan>> rules(boolean optimizeForEsSource) {
+    protected static List<Batch<PhysicalPlan>> rules(boolean optimizeForEsSource) {
         List<Rule<?, PhysicalPlan>> esSourceRules = new ArrayList<>(6);
         esSourceRules.add(new ReplaceSourceAttributes());
-
         if (optimizeForEsSource) {
             esSourceRules.add(new PushTopNToSource());
             esSourceRules.add(new PushLimitToSource());
@@ -81,7 +80,6 @@ protected List<Batch<PhysicalPlan>> rules(boolean optimizeForEsSource) {
             new SpatialDocValuesExtraction(),
             new SpatialShapeBoundsExtraction()
         );
-        return asList(pushdown, fieldExtraction);
+        return List.of(pushdown, fieldExtraction);
     }
-
 }

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/LogicalPlanOptimizer.java

@@ -64,11 +64,10 @@
 import org.elasticsearch.xpack.esql.optimizer.rules.logical.TranslateMetricsAggregate;
 import org.elasticsearch.xpack.esql.plan.logical.LogicalPlan;
 import org.elasticsearch.xpack.esql.rule.ParameterizedRuleExecutor;
+import org.elasticsearch.xpack.esql.rule.RuleExecutor;
 
 import java.util.List;
 
-import static java.util.Arrays.asList;
-
 /**
  * <p>This class is part of the planner</p>
  * <p>Global optimizations based strictly on the structure of the query (i.e. not factoring in information about the backing indices).
@@ -93,6 +92,14 @@
  */
 public class LogicalPlanOptimizer extends ParameterizedRuleExecutor<LogicalPlan, LogicalOptimizerContext> {
 
+    private static final List<RuleExecutor.Batch<LogicalPlan>> RULES = List.of(
+        substitutions(),
+        operators(),
+        new Batch<>("Skip Compute", new SkipQueryOnLimitZero()),
+        cleanup(),
+        new Batch<>("Set as Optimized", Limiter.ONCE, new SetAsOptimized())
+    );
+
     private final LogicalVerifier verifier = LogicalVerifier.INSTANCE;
 
     public LogicalPlanOptimizer(LogicalOptimizerContext optimizerContext) {
@@ -112,14 +119,7 @@ public LogicalPlan optimize(LogicalPlan verified) {
 
     @Override
     protected List<Batch<LogicalPlan>> batches() {
-        return rules();
-    }
-
-    protected static List<Batch<LogicalPlan>> rules() {
-        var skip = new Batch<>("Skip Compute", new SkipQueryOnLimitZero());
-        var label = new Batch<>("Set as Optimized", Limiter.ONCE, new SetAsOptimized());
-
-        return asList(substitutions(), operators(), skip, cleanup(), label);
+        return RULES;
     }
 
     protected static Batch<LogicalPlan> substitutions() {

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/PhysicalPlanOptimizer.java

@@ -18,14 +18,15 @@
 import java.util.Collection;
 import java.util.List;
 
-import static java.util.Arrays.asList;
-
 /**
  * This class is part of the planner. Performs global (coordinator) optimization of the physical plan. Local (data-node) optimizations
  * occur later by operating just on a plan {@link FragmentExec} (subplan).
  */
 public class PhysicalPlanOptimizer extends ParameterizedRuleExecutor<PhysicalPlan, PhysicalOptimizerContext> {
-    private static final Iterable<RuleExecutor.Batch<PhysicalPlan>> rules = initializeRules(true);
+
+    private static final List<RuleExecutor.Batch<PhysicalPlan>> RULES = List.of(
+        new Batch<>("Plan Boundary", Limiter.ONCE, new ProjectAwayColumns())
+    );
 
     private final PhysicalVerifier verifier = PhysicalVerifier.INSTANCE;
 
@@ -45,13 +46,8 @@ PhysicalPlan verify(PhysicalPlan plan) {
         return plan;
     }
 
-    static List<RuleExecutor.Batch<PhysicalPlan>> initializeRules(boolean isOptimizedForEsSource) {
-        var boundary = new Batch<>("Plan Boundary", Limiter.ONCE, new ProjectAwayColumns());
-        return asList(boundary);
-    }
-
     @Override
-    protected Iterable<RuleExecutor.Batch<PhysicalPlan>> batches() {
-        return rules;
+    protected List<RuleExecutor.Batch<PhysicalPlan>> batches() {
+        return RULES;
     }
 }