fix style

backends-clickhouse/src/main/scala/org/apache/gluten/backendsapi/clickhouse/CHIteratorApi.scala

@@ -323,9 +323,11 @@ class CollectMetricIterator(
   private var outputRowCount = 0L
   private var outputVectorCount = 0L
   private var metricsUpdated = false
+  // Whether the stage is executed completely using ClickHouse pipeline.
   private var wholeStagePipeline = true
 
   override def hasNext: Boolean = {
+    // The hasNext call is triggered only when there is a fallback.
     wholeStagePipeline = false
     nativeIterator.hasNext
   }

backends-clickhouse/src/main/scala/org/apache/spark/shuffle/CHColumnarShuffleWriter.scala

@@ -190,26 +190,31 @@ class CHColumnarShuffleWriter[K, V](
 }
 
 object CHColumnarShuffleWriter {
+  private val TOTAL_OUTPUT_ROWS = "total_output_rows"
+
+  private val TOTAL_OUTPUT_BATCHES = "total_output_batches"
+
+  // Pass the statistics of the last operator before shuffle to CollectMetricIterator.
   def setOutputMetrics(splitResult: CHSplitResult): Unit = {
     TaskContext
       .get()
       .getLocalProperties
-      .setProperty("total_output_rows", splitResult.getTotalRows.toString)
+      .setProperty(TOTAL_OUTPUT_ROWS, splitResult.getTotalRows.toString)
     TaskContext
       .get()
       .getLocalProperties
-      .setProperty("total_output_batches", splitResult.getTotalBatches.toString)
+      .setProperty(TOTAL_OUTPUT_BATCHES, splitResult.getTotalBatches.toString)
   }
 
   def getTotalOutputRows(): Long = {
-    val output_rows = TaskContext.get().getLocalProperty("total_output_rows")
+    val output_rows = TaskContext.get().getLocalProperty(TOTAL_OUTPUT_ROWS)
     var output_rows_value = 0L
     if (output_rows != null && output_rows.nonEmpty) output_rows_value = output_rows.toLong
     output_rows_value
   }
 
   def getTotalOutputBatches(): Long = {
-    val output_batches = TaskContext.get().getLocalProperty("total_output_batches")
+    val output_batches = TaskContext.get().getLocalProperty(TOTAL_OUTPUT_BATCHES)
     var output_batches_value = 0L
     if (output_batches != null) output_batches_value = output_batches.toLong
     output_batches_value

cpp-ch/local-engine/Parser/LocalExecutor.cpp

@@ -21,8 +21,7 @@
 #include <QueryPipeline/printPipeline.h>
 #include <Processors/Executors/PipelineExecutor.h>
 #include <Core/Settings.h>
-
-#include "SerializedPlanParser.h"
+#include <Parser/SerializedPlanParser.h>
 
 using namespace DB;
 namespace local_engine
@@ -169,4 +168,4 @@ std::string LocalExecutor::dumpPipeline() const
     DB::printPipeline(processors, out);
     return out.str();
 }
-}
+}

cpp-ch/local-engine/Parser/SerializedPlanParser.cpp

@@ -1321,18 +1321,18 @@ std::unique_ptr<LocalExecutor> SerializedPlanParser::createExecutor(DB::QueryPla
     const Settings & settings = context->getSettingsRef();
     auto builder = buildQueryPipeline(*query_plan);
 
-    ///
+
     assert(s_plan.relations_size() == 1);
     const substrait::PlanRel & root_rel = s_plan.relations().at(0);
     assert(root_rel.has_root());
     if (root_rel.root().input().has_write())
         addSinkTransfrom(context, root_rel.root().input().write(), builder);
-    ///
+
     auto * logger = &Poco::Logger::get("SerializedPlanParser");
     LOG_INFO(logger, "build pipeline {} ms", stopwatch.elapsedMicroseconds() / 1000.0);
     LOG_DEBUG(
         logger, "clickhouse plan [optimization={}]:\n{}", settings.query_plan_enable_optimizations, PlanUtil::explainPlan(*query_plan));
-    // LOG_DEBUG(logger, "clickhouse pipeline:\n{}", QueryPipelineUtil::explainPipeline(pipeline));
+    LOG_DEBUG(logger, "clickhouse pipeline:\n{}", QueryPipelineUtil::explainPipeline(pipeline));
 
     auto config = ExecutorConfig::loadFromContext(context);
     return std::make_unique<LocalExecutor>(std::move(query_plan), std::move(builder), config.dump_pipeline);

cpp-ch/local-engine/Shuffle/SparkExchangeSink.cpp

@@ -386,4 +386,4 @@ std::unordered_map<String, SelectBuilderCreator> SparkExchangeManager::partition
     {"single", createSingleSelectorBuilder},
     {"range", createRangeSelectorBuilder},
 };
-}
+}

cpp-ch/local-engine/Storages/SourceFromJavaIter.cpp

@@ -21,7 +21,6 @@
 #include <Common/CHUtil.h>
 #include <Common/Exception.h>
 #include <Common/JNIUtils.h>
-#include <Common/DebugUtils.h>
 
 namespace DB
 {

cpp-ch/local-engine/local_engine_jni.cpp

@@ -56,7 +56,6 @@
 #include <Common/ErrorCodes.h>
 #include <Processors/Executors/PipelineExecutor.h>
 #include <Storages/Cache/CacheManager.h>
-#include <Common/DebugUtils.h>
 
 #ifdef __cplusplus
 namespace DB

cpp-ch/local-engine/tests/benchmark_local_engine.cpp

@@ -49,6 +49,7 @@
 #include <Common/PODArray_fwd.h>
 #include <Common/Stopwatch.h>
 #include <Common/logger_useful.h>
+#include <Parser/LocalExecutor.h>
 #include "testConfig.h"
 
 #if defined(__SSE2__)