Checkstyle shadows vars pt10 (elastic#81361)

Backport of elastic#81361.

Part of elastic#19752. Fix more instances where local variable names were
shadowing field names.

build-tools-internal/src/main/resources/checkstyle.xml

@@ -97,6 +97,13 @@
 
     <!-- Checks that a local variable or a parameter does not shadow a field that is defined in the same class. -->
     <!-- Use a forked version that understands setters that don't start with "set". -->
+    <!-- Notes on `ignoredMethodNames`:
+
+        * `createParser` creates objects so should be considered a sort-of constructor
+        * `createComponents` by its nature ends up referring to fields
+          a lot, and there's no benefit to flagging shadowed variables in
+          those methods.
+    -->
     <!-- Disabled until existing violations are fixed -->
     <!--
     <module name="org.elasticsearch.gradle.internal.checkstyle.HiddenFieldCheck">
@@ -107,7 +114,7 @@
         <property name="minLineCount" value="5" />
         <property name="ignoreFormat" value="^(?:threadPool)$"/>
         <property name="ignoreAbstractMethods" value="true"/>
-        <property name="ignoreMethodNames" value="^(?:createParser)$"/>
+        <property name="ignoreMethodNames" value="^(?:createParser|createComponents)$"/>
         <property name="setterCanReturnItsClass" value="true"/>
         <message key="hidden.field" value="''{0}'' hides a field." />
     </module>

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MachineLearning.java

@@ -1090,7 +1090,7 @@ public Collection<Module> createGuiceModules() {
 
     @Override
     public List<RestHandler> getRestHandlers(
-        Settings settings,
+        Settings unused,
         RestController restController,
         ClusterSettings clusterSettings,
         IndexScopedSettings indexScopedSettings,
@@ -1264,7 +1264,7 @@ public List<ActionFilter> getActionFilters() {
     }
 
     @Override
-    public List<ExecutorBuilder<?>> getExecutorBuilders(Settings settings) {
+    public List<ExecutorBuilder<?>> getExecutorBuilders(Settings unused) {
         if (false == enabled || transportClientMode) {
             return emptyList();
         }
@@ -1414,7 +1414,7 @@ public List<NamedXContentRegistry.Entry> getNamedXContent() {
     }
 
     @Override
-    public Collection<SystemIndexDescriptor> getSystemIndexDescriptors(Settings settings) {
+    public Collection<SystemIndexDescriptor> getSystemIndexDescriptors(Settings unused) {
         return Collections.unmodifiableList(
             Arrays.asList(
                 SystemIndexDescriptor.builder()
@@ -1695,7 +1695,7 @@ public void cleanUpFeature(
     }
 
     @Override
-    public BreakerSettings getCircuitBreaker(Settings settings) {
+    public BreakerSettings getCircuitBreaker(Settings settingsToUse) {
         return BreakerSettings.updateFromSettings(
             new BreakerSettings(
                 TRAINED_MODEL_CIRCUIT_BREAKER_NAME,
@@ -1704,7 +1704,7 @@ public BreakerSettings getCircuitBreaker(Settings settings) {
                 CircuitBreaker.Type.MEMORY,
                 CircuitBreaker.Durability.TRANSIENT
             ),
-            settings
+            settingsToUse
         );
     }
 

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/MlInitializationService.java

@@ -148,7 +148,7 @@ public void clusterChanged(ClusterChangedEvent event) {
 
         // The atomic flag shortcircuits the check after no legacy templates have been found to exist.
         if (this.isMaster && checkForLegacyMlTemplates.get()) {
-            if (deleteOneMlLegacyTemplateIfNecessary(client, event.state()) == false) {
+            if (deleteOneMlLegacyTemplateIfNecessary(event.state()) == false) {
                 checkForLegacyMlTemplates.set(false);
             }
         }
@@ -158,7 +158,7 @@ public void clusterChanged(ClusterChangedEvent event) {
      * @return <code>true</code> if further calls to this method are worthwhile.
      *         <code>false</code> if this method never needs to be called again.
      */
-    private boolean deleteOneMlLegacyTemplateIfNecessary(Client client, ClusterState state) {
+    private boolean deleteOneMlLegacyTemplateIfNecessary(ClusterState state) {
 
         // Don't delete the legacy templates until the entire cluster is on a version that supports composable templates
         if (state.nodes().getMinNodeVersion().before(MlIndexTemplateRegistry.COMPOSABLE_TEMPLATE_SWITCH_VERSION)) {

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportDeleteExpiredDataAction.java

@@ -132,10 +132,10 @@ protected void doExecute(
         TaskId taskId = new TaskId(clusterService.localNode().getId(), task.getId());
 
         BooleanSupplier isTimedOutSupplier = () -> Instant.now(clock).isAfter(timeoutTime);
-        AnomalyDetectionAuditor auditor = new AnomalyDetectionAuditor(client, clusterService);
+        AnomalyDetectionAuditor anomalyDetectionAuditor = new AnomalyDetectionAuditor(client, clusterService);
 
         if (Strings.isNullOrEmpty(request.getJobId()) || Strings.isAllOrWildcard(request.getJobId())) {
-            List<MlDataRemover> dataRemovers = createDataRemovers(client, taskId, auditor);
+            List<MlDataRemover> dataRemovers = createDataRemovers(client, taskId, anomalyDetectionAuditor);
             threadPool.executor(MachineLearning.UTILITY_THREAD_POOL_NAME)
                 .execute(() -> deleteExpiredData(request, dataRemovers, listener, isTimedOutSupplier));
         } else {
@@ -144,7 +144,7 @@ protected void doExecute(
                     List<Job> jobs = jobBuilders.stream().map(Job.Builder::build).collect(Collectors.toList());
                     String[] jobIds = jobs.stream().map(Job::getId).toArray(String[]::new);
                     request.setExpandedJobIds(jobIds);
-                    List<MlDataRemover> dataRemovers = createDataRemovers(jobs, taskId, auditor);
+                    List<MlDataRemover> dataRemovers = createDataRemovers(jobs, taskId, anomalyDetectionAuditor);
                     deleteExpiredData(request, dataRemovers, listener, isTimedOutSupplier);
                 });
             }, listener::onFailure));
@@ -232,53 +232,57 @@ void deleteExpiredData(
         }
     }
 
-    private List<MlDataRemover> createDataRemovers(OriginSettingClient client, TaskId parentTaskId, AnomalyDetectionAuditor auditor) {
+    private List<MlDataRemover> createDataRemovers(
+        OriginSettingClient originClient,
+        TaskId parentTaskId,
+        AnomalyDetectionAuditor anomalyDetectionAuditor
+    ) {
         return Arrays.asList(
             new ExpiredResultsRemover(
-                client,
-                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(client)),
+                originClient,
+                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(originClient)),
                 parentTaskId,
-                auditor,
+                anomalyDetectionAuditor,
                 threadPool
             ),
-            new ExpiredForecastsRemover(client, threadPool, parentTaskId),
+            new ExpiredForecastsRemover(originClient, threadPool, parentTaskId),
             new ExpiredModelSnapshotsRemover(
-                client,
-                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(client)),
+                originClient,
+                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(originClient)),
                 threadPool,
                 parentTaskId,
                 jobResultsProvider,
-                auditor
+                anomalyDetectionAuditor
             ),
-            new UnusedStateRemover(client, clusterService, parentTaskId),
-            new EmptyStateIndexRemover(client, parentTaskId),
-            new UnusedStatsRemover(client, parentTaskId),
+            new UnusedStateRemover(originClient, clusterService, parentTaskId),
+            new EmptyStateIndexRemover(originClient, parentTaskId),
+            new UnusedStatsRemover(originClient, parentTaskId),
             new ExpiredAnnotationsRemover(
-                client,
-                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(client)),
+                originClient,
+                new WrappedBatchedJobsIterator(new SearchAfterJobsIterator(originClient)),
                 parentTaskId,
-                auditor,
+                anomalyDetectionAuditor,
                 threadPool
             )
         );
     }
 
-    private List<MlDataRemover> createDataRemovers(List<Job> jobs, TaskId parentTaskId, AnomalyDetectionAuditor auditor) {
+    private List<MlDataRemover> createDataRemovers(List<Job> jobs, TaskId parentTaskId, AnomalyDetectionAuditor anomalyDetectionAuditor) {
         return Arrays.asList(
-            new ExpiredResultsRemover(client, new VolatileCursorIterator<>(jobs), parentTaskId, auditor, threadPool),
+            new ExpiredResultsRemover(client, new VolatileCursorIterator<>(jobs), parentTaskId, anomalyDetectionAuditor, threadPool),
             new ExpiredForecastsRemover(client, threadPool, parentTaskId),
             new ExpiredModelSnapshotsRemover(
                 client,
                 new VolatileCursorIterator<>(jobs),
                 threadPool,
                 parentTaskId,
                 jobResultsProvider,
-                auditor
+                anomalyDetectionAuditor
             ),
             new UnusedStateRemover(client, clusterService, parentTaskId),
             new EmptyStateIndexRemover(client, parentTaskId),
             new UnusedStatsRemover(client, parentTaskId),
-            new ExpiredAnnotationsRemover(client, new VolatileCursorIterator<>(jobs), parentTaskId, auditor, threadPool)
+            new ExpiredAnnotationsRemover(client, new VolatileCursorIterator<>(jobs), parentTaskId, anomalyDetectionAuditor, threadPool)
         );
     }
 

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/action/TransportStartDataFrameAnalyticsAction.java

@@ -689,7 +689,7 @@ protected AllocatedPersistentTask createTask(
         public PersistentTasksCustomMetadata.Assignment getAssignment(
             TaskParams params,
             Collection<DiscoveryNode> candidateNodes,
-            ClusterState clusterState
+            @SuppressWarnings("HiddenField") ClusterState clusterState
         ) {
             boolean isMemoryTrackerRecentlyRefreshed = memoryTracker.isRecentlyRefreshed();
             Optional<PersistentTasksCustomMetadata.Assignment> optionalAssignment = getPotentialAssignment(

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/CategorizeTextAggregatorFactory.java

@@ -97,15 +97,15 @@ protected Aggregator createInternal(Aggregator parent, CardinalityUpperBound car
                     + "]"
             );
         }
-        TermsAggregator.BucketCountThresholds bucketCountThresholds = new TermsAggregator.BucketCountThresholds(this.bucketCountThresholds);
-        if (bucketCountThresholds.getShardSize() == CategorizeTextAggregationBuilder.DEFAULT_BUCKET_COUNT_THRESHOLDS.getShardSize()) {
+        TermsAggregator.BucketCountThresholds thresholds = new TermsAggregator.BucketCountThresholds(this.bucketCountThresholds);
+        if (thresholds.getShardSize() == CategorizeTextAggregationBuilder.DEFAULT_BUCKET_COUNT_THRESHOLDS.getShardSize()) {
             // The user has not made a shardSize selection. Use default
             // heuristic to avoid any wrong-ranking caused by distributed
             // counting
             // TODO significant text does a 2x here, should we as well?
-            bucketCountThresholds.setShardSize(BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize()));
+            thresholds.setShardSize(BucketUtils.suggestShardSideQueueSize(thresholds.getRequiredSize()));
         }
-        bucketCountThresholds.ensureValidity();
+        thresholds.ensureValidity();
 
         return new CategorizeTextAggregator(
             name,
@@ -114,7 +114,7 @@ protected Aggregator createInternal(Aggregator parent, CardinalityUpperBound car
             parent,
             indexedFieldName,
             fieldType,
-            bucketCountThresholds,
+            thresholds,
             maxUniqueTokens,
             maxMatchTokens,
             similarityThreshold,

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/InternalCategorizationAggregation.java

@@ -55,14 +55,14 @@ public long getDocCount() {
             return docCount;
         }
 
-        public Bucket reduce(BucketKey key, ReduceContext reduceContext) {
+        public Bucket reduce(BucketKey bucketKey, ReduceContext reduceContext) {
             List<InternalAggregations> innerAggs = new ArrayList<>(toReduce.size());
-            long docCount = 0;
+            long totalDocCount = 0;
             for (Bucket bucket : toReduce) {
                 innerAggs.add(bucket.aggregations);
-                docCount += bucket.docCount;
+                totalDocCount += bucket.docCount;
             }
-            return new Bucket(key, docCount, InternalAggregations.reduce(innerAggs, reduceContext));
+            return new Bucket(bucketKey, totalDocCount, InternalAggregations.reduce(innerAggs, reduceContext));
         }
 
         public DelayedCategorizationBucket add(Bucket bucket) {
@@ -339,7 +339,7 @@ public XContentBuilder doXContentBody(XContentBuilder builder, Params params) th
     }
 
     @Override
-    public InternalCategorizationAggregation create(List<Bucket> buckets) {
+    public InternalCategorizationAggregation create(List<Bucket> bucketList) {
         return new InternalCategorizationAggregation(
             name,
             requiredSize,
@@ -348,7 +348,7 @@ public InternalCategorizationAggregation create(List<Bucket> buckets) {
             maxMatchTokens,
             similarityThreshold,
             super.metadata,
-            buckets
+            bucketList
         );
     }
 

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/inference/InferencePipelineAggregationBuilder.java

@@ -249,11 +249,11 @@ public InferencePipelineAggregationBuilder rewrite(QueryRewriteContext context)
 
         SetOnce<LocalModel> loadedModel = new SetOnce<>();
         BiConsumer<Client, ActionListener<?>> modelLoadAction = (client, listener) -> modelLoadingService.get()
-            .getModelForSearch(modelId, listener.delegateFailure((delegate, model) -> {
-                loadedModel.set(model);
+            .getModelForSearch(modelId, listener.delegateFailure((delegate, localModel) -> {
+                loadedModel.set(localModel);
 
                 boolean isLicensed = MachineLearningField.ML_API_FEATURE.check(licenseState)
-                    || licenseState.isAllowedByLicense(model.getLicenseLevel());
+                    || licenseState.isAllowedByLicense(localModel.getLicenseLevel());
                 if (isLicensed) {
                     delegate.onResponse(null);
                 } else {

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/kstest/BucketCountKSTestAggregator.java

@@ -248,7 +248,7 @@ public InternalAggregation doReduce(Aggregations aggregations, InternalAggregati
             );
         }
         final MlAggsHelper.DoubleBucketValues bucketsValue = maybeBucketsValue.get();
-        double[] fractions = this.fractions == null
+        double[] fractionsArr = this.fractions == null
             ? DoubleStream.concat(
                 DoubleStream.of(0.0),
                 Stream.generate(() -> 1.0 / (bucketsValue.getDocCounts().length - 1))
@@ -258,6 +258,6 @@ public InternalAggregation doReduce(Aggregations aggregations, InternalAggregati
             // We prepend zero to the fractions as we prepend 0 to the doc counts and we want them to be the same length when
             // we create the monotonically increasing values for distribution comparison.
             : DoubleStream.concat(DoubleStream.of(0.0), Arrays.stream(this.fractions)).toArray();
-        return new InternalKSTestAggregation(name(), metadata(), ksTest(fractions, bucketsValue, alternatives, samplingMethod));
+        return new InternalKSTestAggregation(name(), metadata(), ksTest(fractionsArr, bucketsValue, alternatives, samplingMethod));
     }
 }

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/autoscaling/MlAutoscalingDeciderService.java

@@ -559,15 +559,15 @@ public AutoscalingDeciderResult scale(Settings configuration, AutoscalingDecider
             if (nodeLoads.size() > 1) {
                 long totalAssignedJobs = nodeLoads.stream().mapToLong(NodeLoad::getNumAssignedJobs).sum();
                 // one volatile read
-                long maxOpenJobs = this.maxOpenJobs;
-                if (totalAssignedJobs > maxOpenJobs) {
+                long maxOpenJobsCopy = this.maxOpenJobs;
+                if (totalAssignedJobs > maxOpenJobsCopy) {
                     String msg = String.format(
                         Locale.ROOT,
                         "not scaling down as the total number of jobs [%d] exceeds the setting [%s (%d)]. "
                             + " To allow a scale down [%s] must be increased.",
                         totalAssignedJobs,
                         MAX_OPEN_JOBS_PER_NODE.getKey(),
-                        maxOpenJobs,
+                        maxOpenJobsCopy,
                         MAX_OPEN_JOBS_PER_NODE.getKey()
                     );
                     logger.info(

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractor.java

@@ -211,6 +211,7 @@ void markScrollAsErrored() {
         searchHasShardFailure = true;
     }
 
+    @SuppressWarnings("HiddenField")
     protected SearchResponse executeSearchScrollRequest(String scrollId) {
         return ClientHelper.executeWithHeaders(
             context.headers,

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/datafeed/extractor/scroll/ScrollDataExtractorFactory.java

@@ -77,12 +77,10 @@ public static void create(
         ActionListener<DataExtractorFactory> listener
     ) {
 
-        // Step 2. Contruct the factory and notify listener
+        // Step 2. Construct the factory and notify listener
         ActionListener<FieldCapabilitiesResponse> fieldCapabilitiesHandler = ActionListener.wrap(fieldCapabilitiesResponse -> {
-            TimeBasedExtractedFields extractedFields = TimeBasedExtractedFields.build(job, datafeed, fieldCapabilitiesResponse);
-            listener.onResponse(
-                new ScrollDataExtractorFactory(client, datafeed, job, extractedFields, xContentRegistry, timingStatsReporter)
-            );
+            TimeBasedExtractedFields fields = TimeBasedExtractedFields.build(job, datafeed, fieldCapabilitiesResponse);
+            listener.onResponse(new ScrollDataExtractorFactory(client, datafeed, job, fields, xContentRegistry, timingStatsReporter));
         }, e -> {
             Throwable cause = ExceptionsHelper.unwrapCause(e);
             if (cause instanceof IndexNotFoundException) {

x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/dataframe/DataFrameAnalyticsManager.java

@@ -153,7 +153,7 @@ public void execute(DataFrameAnalyticsTask task, ClusterState clusterState, Time
     }
 
     private void createStatsIndexAndUpdateMappingsIfNecessary(
-        Client client,
+        Client clientToUse,
         ClusterState clusterState,
         TimeValue masterNodeTimeout,
         ActionListener<Boolean> listener
@@ -162,15 +162,21 @@ private void createStatsIndexAndUpdateMappingsIfNecessary(
             aBoolean -> ElasticsearchMappings.addDocMappingIfMissing(
                 MlStatsIndex.writeAlias(),
                 MlStatsIndex::wrappedMapping,
-                client,
+                clientToUse,
                 clusterState,
                 masterNodeTimeout,
                 listener
             ),
             listener::onFailure
         );
 
-        MlStatsIndex.createStatsIndexAndAliasIfNecessary(client, clusterState, expressionResolver, masterNodeTimeout, createIndexListener);
+        MlStatsIndex.createStatsIndexAndAliasIfNecessary(
+            clientToUse,
+            clusterState,
+            expressionResolver,
+            masterNodeTimeout,
+            createIndexListener
+        );
     }
 
     private void determineProgressAndResume(DataFrameAnalyticsTask task, DataFrameAnalyticsConfig config) {