use unique_ptr

Author: zhjwpku

src/iceberg/sort_order.cc

@@ -125,24 +125,25 @@ SortOrderBuilder& SortOrderBuilder::CaseSensitive(bool case_sensitive) {
   return *this;
 }
 
-Result<std::shared_ptr<SortOrder>> SortOrderBuilder::BuildUncheckd() {
+Result<std::unique_ptr<SortOrder>> SortOrderBuilder::BuildUncheckd() {
   if (impl_->fields.empty()) {
     if (impl_->sort_id.has_value() && impl_->sort_id != SortOrder::kUnsortedOrderId) {
       return InvalidArgument("Unsorted order ID must be 0");
     }
-    return SortOrder::Unsorted();
+    return std::make_unique<SortOrder>(SortOrder::kUnsortedOrderId,
+                                       std::vector<SortField>{});
   }
 
   if (impl_->sort_id.has_value() && impl_->sort_id == SortOrder::kUnsortedOrderId) {
     return InvalidArgument("Sort order ID 0 is reserved for unsorted order");
   }
 
   // default ID to 1 as 0 is reserved for unsorted order
-  return std::make_shared<SortOrder>(
+  return std::make_unique<SortOrder>(
       impl_->sort_id.value_or(SortOrder::kInitialSortOrderId), std::move(impl_->fields));
 }
 
-Result<std::shared_ptr<SortOrder>> SortOrderBuilder::Build() {
+Result<std::unique_ptr<SortOrder>> SortOrderBuilder::Build() {
   ICEBERG_ASSIGN_OR_RAISE(auto sort_order, BuildUncheckd());
   ICEBERG_RETURN_UNEXPECTED(CheckCompatibility(sort_order, impl_->schema));
   return sort_order;
@@ -180,7 +181,7 @@ SortOrderBuilder& SortOrderBuilder::AddSortField(const std::shared_ptr<Term>& te
   return *this;
 }
 
-Status SortOrderBuilder::CheckCompatibility(const std::shared_ptr<SortOrder>& sort_order,
+Status SortOrderBuilder::CheckCompatibility(const std::unique_ptr<SortOrder>& sort_order,
                                             const Schema* schema) {
   for (const auto& field : sort_order->fields()) {
     ICEBERG_ASSIGN_OR_RAISE(auto schema_field, schema->FindFieldById(field.source_id()));

src/iceberg/sort_order.h

@@ -132,7 +132,7 @@ class ICEBERG_EXPORT SortOrderBuilder {
   /// \brief Builds a SortOrder instance.
   ///
   /// \return A Result containing the constructed SortOrder or an error
-  Result<std::shared_ptr<SortOrder>> Build();
+  Result<std::unique_ptr<SortOrder>> Build();
 
   /// \brief Destructor
   ~SortOrderBuilder();
@@ -153,9 +153,9 @@ class ICEBERG_EXPORT SortOrderBuilder {
                                  SortDirection direction, NullOrder null_order);
 
   /// \brief Builds an unchecked SortOrder instance.
-  Result<std::shared_ptr<SortOrder>> BuildUncheckd();
+  Result<std::unique_ptr<SortOrder>> BuildUncheckd();
 
-  static Status CheckCompatibility(const std::shared_ptr<SortOrder>& sort_order,
+  static Status CheckCompatibility(const std::unique_ptr<SortOrder>& sort_order,
                                    const Schema* schema);
 
   /// Internal state members