Merge pull request #39191 from ClickHouse/sort_transform_cleanup

Cleanup: done during #38719 (SortingStep: deduce way to sort based on input stream sort)

src/Processors/Merges/Algorithms/MergingSortedAlgorithm.cpp

@@ -10,7 +10,7 @@ namespace DB
 MergingSortedAlgorithm::MergingSortedAlgorithm(
     Block header_,
     size_t num_inputs,
-    SortDescription description_,
+    const SortDescription & description_,
     size_t max_block_size,
     SortingQueueStrategy sorting_queue_strategy_,
     UInt64 limit_,
@@ -18,7 +18,7 @@ MergingSortedAlgorithm::MergingSortedAlgorithm(
     bool use_average_block_sizes)
     : header(std::move(header_))
     , merged_data(header.cloneEmptyColumns(), use_average_block_sizes, max_block_size)
-    , description(std::move(description_))
+    , description(description_)
     , limit(limit_)
     , out_row_sources_buf(out_row_sources_buf_)
     , current_inputs(num_inputs)
@@ -29,7 +29,7 @@ MergingSortedAlgorithm::MergingSortedAlgorithm(
     sort_description_types.reserve(description.size());
 
     /// Replace column names in description to positions.
-    for (auto & column_description : description)
+    for (const auto & column_description : description)
     {
         has_collation |= column_description.collator != nullptr;
         sort_description_types.emplace_back(header.getByName(column_description.column_name).type);

src/Processors/Merges/Algorithms/MergingSortedAlgorithm.h

@@ -16,7 +16,7 @@ public:
     MergingSortedAlgorithm(
         Block header_,
         size_t num_inputs,
-        SortDescription description_,
+        const SortDescription & description_,
         size_t max_block_size,
         SortingQueueStrategy sorting_queue_strategy_,
         UInt64 limit_ = 0,
@@ -38,7 +38,7 @@ private:
 
     /// Settings
     SortDescription description;
-    UInt64 limit;
+    const UInt64 limit;
     bool has_collation = false;
 
     /// Used in Vertical merge algorithm to gather non-PK/non-index columns (on next step)

src/Processors/Merges/MergingSortedTransform.cpp

@@ -10,7 +10,7 @@ namespace DB
 MergingSortedTransform::MergingSortedTransform(
     const Block & header,
     size_t num_inputs,
-    SortDescription  description_,
+    const SortDescription & description_,
     size_t max_block_size,
     SortingQueueStrategy sorting_queue_strategy,
     UInt64 limit_,
@@ -19,10 +19,14 @@ MergingSortedTransform::MergingSortedTransform(
     bool use_average_block_sizes,
     bool have_all_inputs_)
     : IMergingTransform(
-        num_inputs, header, header, have_all_inputs_, limit_,
+        num_inputs,
+        header,
+        header,
+        have_all_inputs_,
+        limit_,
         header,
         num_inputs,
-        std::move(description_),
+        description_,
         max_block_size,
         sorting_queue_strategy,
         limit_,

src/Processors/Merges/MergingSortedTransform.h

@@ -14,7 +14,7 @@ public:
     MergingSortedTransform(
         const Block & header,
         size_t num_inputs,
-        SortDescription description,
+        const SortDescription & description,
         size_t max_block_size,
         SortingQueueStrategy sorting_queue_strategy,
         UInt64 limit_ = 0,

src/Processors/Transforms/FinishSortingTransform.cpp

@@ -36,9 +36,8 @@ FinishSortingTransform::FinishSortingTransform(
 
     /// The target description is modified in SortingTransform constructor.
     /// To avoid doing the same actions with description_sorted just copy it from prefix of target description.
-    size_t prefix_size = description_sorted_.size();
-    for (size_t i = 0; i < prefix_size; ++i)
-        description_with_positions.emplace_back(description[i], header_without_constants.getPositionByName(description[i].column_name));
+    for (const auto & column_sort_desc : description_sorted_)
+        description_with_positions.emplace_back(column_sort_desc, header_without_constants.getPositionByName(column_sort_desc.column_name));
 }
 
 void FinishSortingTransform::consume(Chunk chunk)

src/Processors/Transforms/PartialSortingTransform.cpp

@@ -85,7 +85,7 @@ bool compareWithThreshold(const ColumnRawPtrs & raw_block_columns, size_t min_bl
 }
 
 PartialSortingTransform::PartialSortingTransform(
-    const Block & header_, SortDescription & description_, UInt64 limit_)
+    const Block & header_, const SortDescription & description_, UInt64 limit_)
     : ISimpleTransform(header_, header_, false)
     , description(description_)
     , limit(limit_)
@@ -93,9 +93,8 @@ PartialSortingTransform::PartialSortingTransform(
     // Sorting by no columns doesn't make sense.
     assert(!description_.empty());
 
-    size_t description_size = description.size();
-    for (size_t i = 0; i < description_size; ++i)
-        description_with_positions.emplace_back(description[i], header_.getPositionByName(description[i].column_name));
+    for (const auto & column_sort_desc : description)
+        description_with_positions.emplace_back(column_sort_desc, header_.getPositionByName(column_sort_desc.column_name));
 }
 
 void PartialSortingTransform::transform(Chunk & chunk)

src/Processors/Transforms/PartialSortingTransform.h

@@ -15,7 +15,7 @@ public:
     /// limit - if not 0, then you can sort each block not completely, but only `limit` first rows by order.
     PartialSortingTransform(
         const Block & header_,
-        SortDescription & description_,
+        const SortDescription & description_,
         UInt64 limit_ = 0);
 
     String getName() const override { return "PartialSortingTransform"; }
@@ -26,9 +26,9 @@ protected:
     void transform(Chunk & chunk) override;
 
 private:
-    SortDescription description;
+    const SortDescription description;
     SortDescriptionWithPositions description_with_positions;
-    UInt64 limit;
+    const UInt64 limit;
     RowsBeforeLimitCounterPtr read_rows;
 
     Columns sort_description_threshold_columns;

src/Processors/Transforms/SortingTransform.h

@@ -73,8 +73,8 @@ public:
     ~SortingTransform() override;
 
 protected:
-    Status prepare() override final;
-    void work() override final;
+    Status prepare() final;
+    void work() final;
 
     virtual void consume(Chunk chunk) = 0;
     virtual void generate() = 0;
@@ -82,7 +82,7 @@ protected:
 
     SortDescription description;
     size_t max_merged_block_size;
-    UInt64 limit;
+    const UInt64 limit;
 
     /// Before operation, will remove constant columns from blocks. And after, place constant columns back.
     /// (to avoid excessive virtual function calls and because constants cannot be serialized in Native format for temporary files)