Mark some functions of RowContainer as const (facebookincubator#11510)

Summary:
Some functions of RowContainer should be const, and then prefix sort RowContainer can be const also, change both in this PR.

Pull Request resolved: facebookincubator#11510

Reviewed By: gggrace14

Differential Revision: D65803417

Pulled By: xiaoxmeng

fbshipit-source-id: 8e28c29528cd0c603e75bb94040f57bded5f413d

velox/exec/PrefixSort.cpp

@@ -193,7 +193,7 @@ int PrefixSort::comparePartNormalizedKeys(char* left, char* right) {
 }
 
 PrefixSort::PrefixSort(
-    RowContainer* rowContainer,
+    const RowContainer* rowContainer,
     const PrefixSortLayout& sortLayout,
     memory::MemoryPool* pool)
     : rowContainer_(rowContainer), sortLayout_(sortLayout), pool_(pool) {}
@@ -229,7 +229,7 @@ void PrefixSort::extractRowAndEncodePrefixKeys(char* row, char* prefixBuffer) {
 
 // static.
 uint32_t PrefixSort::maxRequiredBytes(
-    RowContainer* rowContainer,
+    const RowContainer* rowContainer,
     const std::vector<CompareFlags>& compareFlags,
     const velox::common::PrefixSortConfig& config,
     memory::MemoryPool* pool) {
@@ -250,7 +250,7 @@ uint32_t PrefixSort::maxRequiredBytes(
 // static
 void PrefixSort::stdSort(
     std::vector<char*, memory::StlAllocator<char*>>& rows,
-    RowContainer* rowContainer,
+    const RowContainer* rowContainer,
     const std::vector<CompareFlags>& compareFlags) {
   std::sort(
       rows.begin(), rows.end(), [&](const char* leftRow, const char* rightRow) {

velox/exec/PrefixSort.h

@@ -72,7 +72,7 @@ struct PrefixSortLayout {
 class PrefixSort {
  public:
   PrefixSort(
-      RowContainer* rowContainer,
+      const RowContainer* rowContainer,
       const PrefixSortLayout& sortLayout,
       memory::MemoryPool* pool);
 
@@ -100,7 +100,7 @@ class PrefixSort {
   /// @param rows The result of RowContainer::listRows(), assuming that the
   /// caller (SortBuffer etc.) has already got the result.
   FOLLY_ALWAYS_INLINE static void sort(
-      RowContainer* rowContainer,
+      const RowContainer* rowContainer,
       const std::vector<CompareFlags>& compareFlags,
       const velox::common::PrefixSortConfig& config,
       memory::MemoryPool* pool,
@@ -128,7 +128,7 @@ class PrefixSort {
   /// such as prefix data. The logic is similar to the above function
   /// PrefixSort::sort but returns the maximum buffer the sort may need.
   static uint32_t maxRequiredBytes(
-      RowContainer* rowContainer,
+      const RowContainer* rowContainer,
       const std::vector<CompareFlags>& compareFlags,
       const velox::common::PrefixSortConfig& config,
       memory::MemoryPool* pool);
@@ -139,7 +139,7 @@ class PrefixSort {
   /// user experienced data.
   static void stdSort(
       std::vector<char*, memory::StlAllocator<char*>>& rows,
-      RowContainer* rowContainer,
+      const RowContainer* rowContainer,
       const std::vector<CompareFlags>& compareFlags);
 
   // Estimates the memory required for prefix sort such as prefix buffer and
@@ -161,7 +161,7 @@ class PrefixSort {
         prefixBuffer + sortLayout_.normalizedBufferSize);
   }
 
-  RowContainer* const rowContainer_;
+  const RowContainer* const rowContainer_;
   const PrefixSortLayout sortLayout_;
   memory::MemoryPool* const pool_;
 };

velox/exec/RowContainer.cpp

@@ -346,7 +346,7 @@ void RowContainer::eraseRows(folly::Range<char**> rows) {
   numFreeRows_ += rows.size();
 }
 
-int32_t RowContainer::findRows(folly::Range<char**> rows, char** result) {
+int32_t RowContainer::findRows(folly::Range<char**> rows, char** result) const {
   raw_vector<folly::Range<char*>> ranges;
   ranges.resize(rows_.numRanges());
   for (auto i = 0; i < rows_.numRanges(); ++i) {
@@ -424,7 +424,7 @@ void RowContainer::freeVariableWidthFields(folly::Range<char**> rows) {
   }
 }
 
-void RowContainer::checkConsistency() {
+void RowContainer::checkConsistency() const {
   constexpr int32_t kBatch = 1000;
   std::vector<char*> rows(kBatch);
 
@@ -563,7 +563,8 @@ std::unique_ptr<ByteInputStream> RowContainer::prepareRead(
       HashStringAllocator::headerOf(view->data()));
 }
 
-int32_t RowContainer::variableSizeAt(const char* row, column_index_t column) {
+int32_t RowContainer::variableSizeAt(const char* row, column_index_t column)
+    const {
   const auto rowColumn = rowColumns_[column];
 
   if (isNullAt(row, rowColumn)) {
@@ -580,14 +581,14 @@ int32_t RowContainer::variableSizeAt(const char* row, column_index_t column) {
   }
 }
 
-int32_t RowContainer::fixedSizeAt(column_index_t column) {
+int32_t RowContainer::fixedSizeAt(column_index_t column) const {
   return typeKindSize(typeKinds_[column]);
 }
 
 int32_t RowContainer::extractVariableSizeAt(
     const char* row,
     column_index_t column,
-    char* output) {
+    char* output) const {
   const auto rowColumn = rowColumns_[column];
 
   // 4 bytes for size + N bytes for data.
@@ -660,7 +661,7 @@ int32_t RowContainer::storeVariableSizeAt(
 
 void RowContainer::extractSerializedRows(
     folly::Range<char**> rows,
-    const VectorPtr& result) {
+    const VectorPtr& result) const {
   // The format of the extracted row is: null bytes followed by keys and
   // dependent columns. Fixed-width columns are serialized into fixed number of
   // bytes (see typeKindSize). Variable-width columns are serialized as 4 bytes
@@ -815,7 +816,7 @@ int RowContainer::compareComplexType(
     int32_t offset,
     const DecodedVector& decoded,
     vector_size_t index,
-    CompareFlags flags) {
+    CompareFlags flags) const {
   VELOX_DCHECK(flags.nullAsValue(), "not supported null handling mode");
 
   auto stream = prepareRead(row, offset);
@@ -835,7 +836,7 @@ int32_t RowContainer::compareComplexType(
     const Type* type,
     int32_t leftOffset,
     int32_t rightOffset,
-    CompareFlags flags) {
+    CompareFlags flags) const {
   VELOX_DCHECK(flags.nullAsValue(), "not supported null handling mode");
 
   auto leftStream = prepareRead(left, leftOffset);
@@ -848,7 +849,7 @@ int32_t RowContainer::compareComplexType(
     const char* right,
     const Type* type,
     int32_t offset,
-    CompareFlags flags) {
+    CompareFlags flags) const {
   return compareComplexType(left, right, type, offset, offset, flags);
 }
 
@@ -859,7 +860,7 @@ void RowContainer::hashTyped(
     bool nullable,
     folly::Range<char**> rows,
     bool mix,
-    uint64_t* result) {
+    uint64_t* result) const {
   using T = typename KindToFlatVector<Kind>::HashRowType;
 
   auto offset = column.offset();
@@ -899,7 +900,7 @@ void RowContainer::hash(
     int32_t column,
     folly::Range<char**> rows,
     bool mix,
-    uint64_t* result) {
+    uint64_t* result) const {
   if (typeKinds_[column] == TypeKind::UNKNOWN) {
     for (auto i = 0; i < rows.size(); ++i) {
       result[i] = mix ? bits::hashMix(result[i], BaseVector::kNullHash)
@@ -973,7 +974,7 @@ void RowContainer::extractProbedFlags(
     int32_t numRows,
     bool setNullForNullKeysRow,
     bool setNullForNonProbedRow,
-    const VectorPtr& result) {
+    const VectorPtr& result) const {
   result->resize(numRows);
   result->clearAllNulls();
   auto flatResult = result->as<FlatVector<bool>>();
@@ -1029,7 +1030,7 @@ int64_t RowContainer::sizeIncrement(
       bits::roundUp(needBytes, kAllocUnit);
 }
 
-void RowContainer::skip(RowContainerIterator& iter, int32_t numRows) {
+void RowContainer::skip(RowContainerIterator& iter, int32_t numRows) const {
   VELOX_DCHECK(accumulators_.empty(), "Used in join only");
   VELOX_DCHECK_LE(0, numRows);
   if (!iter.endOfRun) {
@@ -1087,7 +1088,7 @@ int32_t RowContainer::listPartitionRows(
     uint8_t partition,
     int32_t maxRows,
     const RowPartitions& rowPartitions,
-    char** result) {
+    char** result) const {
   VELOX_CHECK(
       !mutable_, "Can't list partition rows from a mutable row container");
   VELOX_CHECK_EQ(