add const to local variables

5 files changed, 38 insertions, 39 deletions

diff --git a/ydb/core/tx/columnshard/columnshard_private_events.h b/ydb/core/tx/columnshard/columnshard_private_events.h
index c5dbd88e8b0..377f8782f56 100644
--- a/ydb/core/tx/columnshard/columnshard_private_events.h
+++ b/ydb/core/tx/columnshard/columnshard_private_events.h
@@ -72,7 +72,7 @@ struct TEvPrivate {
             GroupedBlobRanges = NOlap::TColumnEngineChanges::GroupedBlobRanges(TxEvent->IndexChanges->SwitchedPortions);
 
             if (blobManager.HasExternBlobs()) {
-                for (auto& [blobId, _] : GroupedBlobRanges) {
+                for (const auto& [blobId, _] : GroupedBlobRanges) {
                     TEvictMetadata meta;
                     if (blobManager.GetEvicted(blobId, meta).IsExternal()) {
                         Externals.insert(blobId);
diff --git a/ydb/core/tx/columnshard/engines/column_engine.h b/ydb/core/tx/columnshard/engines/column_engine.h
index 58cbf391acf..4fc878fe033 100644
--- a/ydb/core/tx/columnshard/engines/column_engine.h
+++ b/ydb/core/tx/columnshard/engines/column_engine.h
@@ -147,10 +147,10 @@ public:
     THashMap<TUnifiedBlobId, std::shared_ptr<arrow::RecordBatch>> CachedBlobs;
     bool NeedRepeat{false};
 
-    bool IsInsert() const { return Type == INSERT; }
-    bool IsCompaction() const { return Type == COMPACTION; }
-    bool IsCleanup() const { return Type == CLEANUP; }
-    bool IsTtl() const { return Type == TTL; }
+    bool IsInsert() const noexcept { return Type == INSERT; }
+    bool IsCompaction() const noexcept { return Type == COMPACTION; }
+    bool IsCleanup() const noexcept { return Type == CLEANUP; }
+    bool IsTtl() const noexcept { return Type == TTL; }
 
     const char * TypeString() const {
         switch (Type) {
@@ -170,36 +170,38 @@ public:
 
     ui64 TotalBlobsSize() const {
         ui64 size = 0;
-        for (auto& [blobId, blob] : Blobs) {
+        for (const auto& [_, blob] : Blobs) {
             size += blob.size();
         }
         return size;
     }
 
+    /// Returns blob-ranges grouped by blob-id.
     static THashMap<TUnifiedBlobId, std::vector<TBlobRange>>
     GroupedBlobRanges(const TVector<TPortionInfo>& portions) {
         Y_VERIFY(portions.size());
 
         THashMap<TUnifiedBlobId, std::vector<TBlobRange>> sameBlobRanges;
-        for (auto& portionInfo : portions) {
+        for (const auto& portionInfo : portions) {
             Y_VERIFY(!portionInfo.Empty());
 
-            for (auto& rec : portionInfo.Records) {
+            for (const auto& rec : portionInfo.Records) {
                 sameBlobRanges[rec.BlobRange.BlobId].push_back(rec.BlobRange);
             }
         }
         return sameBlobRanges;
     }
 
+    /// Returns blob-ranges grouped by blob-id.
     static THashMap<TUnifiedBlobId, std::vector<TBlobRange>>
     GroupedBlobRanges(const TVector<std::pair<TPortionInfo, TPortionEvictionFeatures>>& portions) {
         Y_VERIFY(portions.size());
 
         THashMap<TUnifiedBlobId, std::vector<TBlobRange>> sameBlobRanges;
-        for (auto& [portionInfo, _] : portions) {
+        for (const auto& [portionInfo, _] : portions) {
             Y_VERIFY(!portionInfo.Empty());
 
-            for (auto& rec : portionInfo.Records) {
+            for (const auto& rec : portionInfo.Records) {
                 sameBlobRanges[rec.BlobRange.BlobId].push_back(rec.BlobRange);
             }
         }
diff --git a/ydb/core/tx/columnshard/engines/column_engine_logs.cpp b/ydb/core/tx/columnshard/engines/column_engine_logs.cpp
index 8c0153d3a78..2c3a607e285 100644
--- a/ydb/core/tx/columnshard/engines/column_engine_logs.cpp
+++ b/ydb/core/tx/columnshard/engines/column_engine_logs.cpp
@@ -110,13 +110,13 @@ bool UpdateEvictedPortion(TPortionInfo& portionInfo, const TIndexInfo& indexInfo
     return true;
 }
 
-TVector<TPortionInfo> MakeAppendedPortions(ui64 pathId, const TIndexInfo& indexInfo,
-                                           std::shared_ptr<arrow::RecordBatch> batch,
-                                           ui64 granule,
+TVector<TPortionInfo> MakeAppendedPortions(const ui64 pathId, const TIndexInfo& indexInfo,
+                                           const std::shared_ptr<arrow::RecordBatch> batch,
+                                           const ui64 granule,
                                            const TSnapshot& minSnapshot,
                                            TVector<TString>& blobs) {
     Y_VERIFY(batch->num_rows());
-    auto schema = indexInfo.ArrowSchemaWithSpecials();
+    const auto schema = indexInfo.ArrowSchemaWithSpecials();
     TVector<TPortionInfo> out;
 
     TString tierName;
@@ -124,12 +124,12 @@ TVector<TPortionInfo> MakeAppendedPortions(ui64 pathId, const TIndexInfo& indexI
     if (pathId) {
         if (auto* tiering = indexInfo.GetTiering(pathId)) {
             tierName = tiering->GetHottestTierName();
-            if (auto tierCompression = tiering->GetCompression(tierName)) {
+            if (const auto& tierCompression = tiering->GetCompression(tierName)) {
                 compression = *tierCompression;
             }
         }
     }
-    auto writeOptions = WriteOptions(compression);
+    const auto writeOptions = WriteOptions(compression);
 
     std::shared_ptr<arrow::RecordBatch> portionBatch = batch;
     for (i32 pos = 0; pos < batch->num_rows();) {
@@ -143,7 +143,7 @@ TVector<TPortionInfo> MakeAppendedPortions(ui64 pathId, const TIndexInfo& indexI
         // Serialize portion's columns into blobs
 
         bool ok = true;
-        for (auto& field : schema->fields()) {
+        for (const auto& field : schema->fields()) {
             const auto& name = field->name();
             ui32 columnId = indexInfo.GetColumnId(TString(name.data(), name.size()));
 
@@ -171,7 +171,7 @@ TVector<TPortionInfo> MakeAppendedPortions(ui64 pathId, const TIndexInfo& indexI
                 portionBatch = batch->Slice(pos);
             }
         } else {
-            i64 halfLen = portionBatch->num_rows() / 2;
+            const i64 halfLen = portionBatch->num_rows() / 2;
             Y_VERIFY(halfLen);
             portionBatch = batch->Slice(pos, halfLen);
         }
@@ -211,7 +211,7 @@ bool InitInGranuleMerge(const TMark& granuleMark, TVector<TPortionInfo>& portion
     {
         TMap<NArrow::TReplaceKey, TVector<const TPortionInfo*>> points;
 
-        for (auto& portionInfo : portions) {
+        for (const auto& portionInfo : portions) {
             if (portionInfo.IsInserted()) {
                 ++insertedCount;
                 if (portionInfo.Snapshot().PlanStep > oldTimePlanStep) {
@@ -232,8 +232,8 @@ bool InitInGranuleMerge(const TMark& granuleMark, TVector<TPortionInfo>& portion
         ui64 bucketStartPortion = 0;
         bool isGood = false;
         int sum = 0;
-        for (auto& [key, vec] : points) {
-            for (auto& portionInfo : vec) {
+        for (const auto& [key, vec] : points) {
+            for (const auto* portionInfo : vec) {
                 if (portionInfo) {
                     ++sum;
                     ui64 currentPortion = portionInfo->Portion();
@@ -285,7 +285,7 @@ bool InitInGranuleMerge(const TMark& granuleMark, TVector<TPortionInfo>& portion
 
     TVector<TPortionInfo> tmp;
     tmp.reserve(portions.size());
-    for (auto& portionInfo : portions) {
+    for (const auto& portionInfo : portions) {
         ui64 curPortion = portionInfo.Portion();
 
         // Prevent merge of compacted portions with no intersections
@@ -1698,7 +1698,7 @@ static std::shared_ptr<arrow::RecordBatch> CompactInOneGranule(const TIndexInfo&
 
 static TVector<TString> CompactInGranule(const TIndexInfo& indexInfo,
                                          std::shared_ptr<TColumnEngineForLogs::TChanges> changes) {
-    ui64 pathId = changes->SrcGranule->PathId;
+    const ui64 pathId = changes->SrcGranule->PathId;
     TVector<TString> blobs;
     auto& switchedProtions = changes->SwitchedPortions;
     Y_VERIFY(switchedProtions.size());
@@ -1738,14 +1738,14 @@ static TVector<TString> CompactInGranule(const TIndexInfo& indexInfo,
 static TVector<std::pair<TMark, std::shared_ptr<arrow::RecordBatch>>>
 SliceGranuleBatches(const TIndexInfo& indexInfo,
                     const TColumnEngineForLogs::TChanges& changes,
-                    std::vector<std::shared_ptr<arrow::RecordBatch>>&& batches,
+                    const std::vector<std::shared_ptr<arrow::RecordBatch>>& batches,
                     const TMark& ts0) {
     TVector<std::pair<TMark, std::shared_ptr<arrow::RecordBatch>>> out;
 
     // Extract unique effective keys and their counts
     i64 numRows = 0;
     TMap<NArrow::TReplaceKey, ui32> uniqKeyCount;
-    for (auto& batch : batches) {
+    for (const auto& batch : batches) {
         Y_VERIFY(batch);
         if (batch->num_rows() == 0) {
             continue;
@@ -1804,7 +1804,7 @@ SliceGranuleBatches(const TIndexInfo& indexInfo,
     // Find offsets in source batches
     TVector<TVector<int>> offsets(batches.size()); // vec[batch][border] = offset
     for (size_t i = 0; i < batches.size(); ++i) {
-        auto& batch = batches[i];
+        const auto& batch = batches[i];
         auto& batchOffsets = offsets[i];
         batchOffsets.reserve(borders.size() + 1);
 
@@ -1838,7 +1838,7 @@ SliceGranuleBatches(const TIndexInfo& indexInfo,
         // Extract granule: slice source batches with offsets
         i64 granuleNumRows = 0;
         for (size_t i = 0; i < batches.size(); ++i) {
-            auto& batch = batches[i];
+            const auto& batch = batches[i];
             auto& batchOffsets = offsets[i];
 
             int offset = batchOffsets[granuleNo];
@@ -1971,7 +1971,7 @@ static TVector<TString> CompactSplitGranule(const TIndexInfo& indexInfo,
 
     std::vector<std::pair<TMark, ui64>> tsIds;
     ui64 movedRows = TryMovePortions(ts0, portions, tsIds, changes->PortionsToMove);
-    auto srcBatches = PortionsToBatches(indexInfo, portions, changes->Blobs, movedRows != 0);
+    const auto& srcBatches = PortionsToBatches(indexInfo, portions, changes->Blobs, movedRows != 0);
     Y_VERIFY(srcBatches.size() == portions.size());
 
     TVector<TString> blobs;
@@ -1983,7 +1983,7 @@ static TVector<TString> CompactSplitGranule(const TIndexInfo& indexInfo,
 
         // Calculate total number of rows.
         ui64 numRows = movedRows;
-        for (auto& batch : srcBatches) {
+        for (const auto& batch : srcBatches) {
             numRows += batch->num_rows();
         }
 
@@ -2071,7 +2071,7 @@ static TVector<TString> CompactSplitGranule(const TIndexInfo& indexInfo,
             }
         }
     } else {
-        auto batches = SliceGranuleBatches(indexInfo, *changes, std::move(srcBatches), ts0);
+        auto batches = SliceGranuleBatches(indexInfo, *changes, srcBatches, ts0);
 
         changes->SetTmpGranule(pathId, ts0);
         for (auto& [ts, batch] : batches) {
diff --git a/ydb/core/tx/columnshard/engines/column_engine_logs.h b/ydb/core/tx/columnshard/engines/column_engine_logs.h
index 396daf9cab8..6608fe67569 100644
--- a/ydb/core/tx/columnshard/engines/column_engine_logs.h
+++ b/ydb/core/tx/columnshard/engines/column_engine_logs.h
@@ -118,7 +118,7 @@ public:
 
         THashMap<ui64, ui64> TmpToNewGranules(ui64 start) {
             THashMap<ui64, ui64> granuleRemap;
-            for (auto& [mark, counter] : TmpGranuleIds) {
+            for (const auto& [mark, counter] : TmpGranuleIds) {
                 ui64 granule = start + counter;
                 if (mark == SrcGranule->Mark) {
                     Y_VERIFY(!counter);
@@ -132,14 +132,11 @@ public:
             return granuleRemap;
         }
 
-        ui32 NumSplitInto(ui32 srcRows) const {
+        ui32 NumSplitInto(const ui32 srcRows) const {
             Y_VERIFY(srcRows > 1);
-            ui64 totalBytes = TotalBlobsSize();
-            ui32 numSplitInto = totalBytes / Limits.GranuleExpectedSize + 1;
-            if (numSplitInto < 2) {
-                numSplitInto = 2;
-            }
-            return numSplitInto;
+            const ui64 totalBytes = TotalBlobsSize();
+            const ui32 numSplitInto = (totalBytes / Limits.GranuleExpectedSize) + 1;
+            return std::max<ui32>(2, numSplitInto);
         }
 
         TMark DefaultMark;
diff --git a/ydb/core/tx/columnshard/engines/portion_info.cpp b/ydb/core/tx/columnshard/engines/portion_info.cpp
index c0d34a36c55..f5174fd6068 100644
--- a/ydb/core/tx/columnshard/engines/portion_info.cpp
+++ b/ydb/core/tx/columnshard/engines/portion_info.cpp
@@ -18,7 +18,7 @@ TString TPortionInfo::AddOneChunkColumn(const std::shared_ptr<arrow::Array>& arr
                                         const std::shared_ptr<arrow::Field>& field,
                                         TColumnRecord&& record,
                                         const arrow::ipc::IpcWriteOptions& writeOptions,
-                                        ui32 limitBytes) {
+                                        const ui32 limitBytes) {
     auto blob = SerializeColumn(array, field, writeOptions);
     if (blob.size() >= limitBytes) {
         return {};