Fix fb_reshape_row for ArrayType equal comparison (#11169)

Summary:

fb_reshape_row returns wrong result for array of row when "from" and "to" row
types are the same size and same type but different names.

For example:
```
SELECT
    fb_reshape_row(
        col,
        CAST(NULL AS ROW(arr ARRAY(ROW(b VARCHAR, a VARCHAR))))
    ) as col
FROM (
    SELECT CAST(ROW(x) AS ROW(arr ARRAY(ROW(a VARCHAR, b VARCHAR)))) AS col
    FROM (
    VALUES
        (ARRAY[('1', '2')])
    ) t(x)
);
```

In fb_reshape_row::reshapeRow, if it finds fromType is equal to toType, it will not
do transformation
```
if (fromVector->type()->asRow().equals(toType->asRow())) {
      return fromVector;
    }
```

For `RowType::equals` comparison, it will iterate its children and apply
`operator==` for equal comparison. However `operator==`  is not
defined for `ArrayType` and the equal logic fall back to use
ArrayType::equivalent which is weakly matched.

Change `operator==`  to use `equals` for complex type to ensure strongly
matching for equal comparison

Differential Revision: D63993116

velox/type/Type.cpp

@@ -244,6 +244,17 @@ bool ArrayType::equivalent(const Type& other) const {
   return child_->equivalent(*otherArray.child_);
 }
 
+bool ArrayType::equals(const Type& other) const {
+  if (&other == this) {
+    return true;
+  }
+  if (!Type::hasSameTypeId(other)) {
+    return false;
+  }
+  auto& otherArray = other.asArray();
+  return *child_ == *otherArray.child_;
+}
+
 folly::dynamic ArrayType::serialize() const {
   folly::dynamic obj = folly::dynamic::object;
   obj["name"] = "Type";
@@ -476,14 +487,6 @@ bool RowType::equals(const Type& other) const {
   return true;
 }
 
-bool RowType::operator==(const Type& other) const {
-  return this->equals(other);
-}
-
-bool RowType::operator==(const RowType& other) const {
-  return this->equals(other);
-}
-
 void RowType::printChildren(std::stringstream& ss, std::string_view delimiter)
     const {
   bool any = false;
@@ -569,6 +572,17 @@ bool MapType::equivalent(const Type& other) const {
       valueType_->equivalent(*otherMap.valueType_);
 }
 
+bool MapType::equals(const Type& other) const {
+  if (&other == this) {
+    return true;
+  }
+  if (!Type::hasSameTypeId(other)) {
+    return false;
+  }
+  auto& otherMap = other.asMap();
+  return *keyType_ == *otherMap.keyType_ && *valueType_ == *otherMap.valueType_;
+}
+
 FunctionType::FunctionType(
     std::vector<std::shared_ptr<const Type>>&& argumentTypes,
     std::shared_ptr<const Type> returnType)
@@ -598,6 +612,29 @@ bool FunctionType::equivalent(const Type& other) const {
   return true;
 }
 
+bool FunctionType::equals(const Type& other) const {
+  if (&other == this) {
+    return true;
+  }
+
+  if (!Type::hasSameTypeId(other)) {
+    return false;
+  }
+
+  auto& otherTyped = *reinterpret_cast<const FunctionType*>(&other);
+  if (children_.size() != otherTyped.size()) {
+    return false;
+  }
+
+  for (auto i = 0; i < children_.size(); ++i) {
+    if (*children_.at(i) != *otherTyped.children_.at(i)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 std::string FunctionType::toString() const {
   std::stringstream out;
   out << "FUNCTION<";
@@ -629,11 +666,11 @@ bool OpaqueType::equivalent(const Type& other) const {
   return true;
 }
 
-bool OpaqueType::operator==(const Type& other) const {
+bool OpaqueType::equals(const Type& other) const {
   if (&other == this) {
     return true;
   }
-  if (!this->equivalent(other)) {
+  if (*this != other) {
     return false;
   }
   auto& otherTyped = *reinterpret_cast<const OpaqueType*>(&other);

velox/type/Type.h

@@ -32,6 +32,7 @@
 #include <vector>
 
 #include "velox/common/base/ClassName.h"
+#include "velox/common/base/Exceptions.h"
 #include "velox/common/serialization/Serializable.h"
 #include "velox/type/HugeInt.h"
 #include "velox/type/StringView.h"
@@ -492,12 +493,10 @@ class Type : public Tree<const TypePtr>, public velox::ISerializable {
   /// equivalent if the typeKind matches, but the typeIndex could be different.
   virtual bool equivalent(const Type& other) const = 0;
 
-  /// Types are strongly matched.
-  /// Examples: Two RowTypes are == if the children types and the children names
-  /// are same. Two OpaqueTypes are == if the typeKind and the typeIndex are
-  /// same. Same as equivalent for most types except for Row, Opaque types.
+  /// For Complex types (Row, Array, Map, Opaque): types are strongly matched.
+  /// For primitive types: same as equivalent.
   virtual bool operator==(const Type& other) const {
-    return this->equivalent(other);
+    return this->equals(other);
   }
 
   inline bool operator!=(const Type& other) const {
@@ -566,6 +565,16 @@ class Type : public Tree<const TypePtr>, public velox::ISerializable {
     return typeid(*this) == typeid(other);
   }
 
+  /// For Complex types (Row, Array, Map, Opaque): types are strongly matched.
+  /// Examples: Two RowTypes are == if the children types and the children names
+  /// are same. Two OpaqueTypes are == if the typeKind and the typeIndex are
+  /// same.
+  /// For primitive types: same as equivalent.
+  virtual bool equals(const Type& other) const {
+    VELOX_CHECK(this->isPrimitiveType());
+    return this->equivalent(other);
+  }
+
  private:
   const TypeKind kind_;
   const bool providesCustomComparison_;
@@ -914,6 +923,8 @@ class ArrayType : public TypeBase<TypeKind::ARRAY> {
   }
 
  protected:
+  bool equals(const Type& other) const override;
+
   TypePtr child_;
   const std::vector<TypeParameter> parameters_;
 };
@@ -965,6 +976,9 @@ class MapType : public TypeBase<TypeKind::MAP> {
     return parameters_;
   }
 
+ protected:
+  bool equals(const Type& other) const override;
+
  private:
   TypePtr keyType_;
   TypePtr valueType_;
@@ -1005,10 +1019,6 @@ class RowType : public TypeBase<TypeKind::ROW> {
 
   bool equivalent(const Type& other) const override;
 
-  bool equals(const Type& other) const;
-  bool operator==(const Type& other) const override;
-  bool operator==(const RowType& other) const;
-
   std::string toString() const override;
 
   /// Print child names and types separated by 'delimiter'.
@@ -1037,6 +1047,9 @@ class RowType : public TypeBase<TypeKind::ROW> {
     return *parameters;
   }
 
+ protected:
+  bool equals(const Type& other) const override;
+
  private:
   std::unique_ptr<std::vector<TypeParameter>> makeParameters() const;
 
@@ -1090,6 +1103,9 @@ class FunctionType : public TypeBase<TypeKind::FUNCTION> {
     return parameters_;
   }
 
+ protected:
+  bool equals(const Type& other) const override;
+
  private:
   static std::vector<std::shared_ptr<const Type>> allChildren(
       std::vector<std::shared_ptr<const Type>>&& argumentTypes,
@@ -1124,8 +1140,6 @@ class OpaqueType : public TypeBase<TypeKind::OPAQUE> {
 
   bool equivalent(const Type& other) const override;
 
-  bool operator==(const Type& other) const override;
-
   const std::type_index& typeIndex() const {
     return typeIndex_;
   }
@@ -1186,6 +1200,9 @@ class OpaqueType : public TypeBase<TypeKind::OPAQUE> {
         deserializeTypeErased);
   }
 
+ protected:
+  bool equals(const Type& other) const override;
+
  private:
   const std::type_index typeIndex_;
 

velox/vector/tests/VectorMakerTest.cpp

@@ -596,7 +596,9 @@ TEST_F(VectorMakerTest, arrayOfRowVectorFromTuples) {
   auto expected = maker_.arrayVector(offsets, elements);
 
   ASSERT_EQ(expected->size(), arrayVector->size());
-  ASSERT_EQ(*expected->type(), *arrayVector->type());
+  // check equivalent because arrayVector's row type doesn't have name for each
+  // column ('', '' ..) whereas expected's row type have names ('c0', 'c1' ..)
+  ASSERT_TRUE((*expected->type()).equivalent((*arrayVector->type())));
   for (auto i = 0; i < expected->size(); i++) {
     ASSERT_TRUE(expected->equalValueAt(arrayVector.get(), i, i));
   }