R-JunmingChen commented on code in PR #37100:
URL: https://github.com/apache/arrow/pull/37100#discussion_r1299398307


##########
cpp/src/arrow/compute/kernels/aggregate_basic_internal.h:
##########
@@ -891,6 +891,105 @@ struct NullMinMaxImpl : public ScalarAggregator {
   }
 };
 
+template <SimdLevel::type SimdLevel>
+struct DictionaryMinMaxImpl : public ScalarAggregator {
+  using ThisType = DictionaryMinMaxImpl<SimdLevel>;
+
+  DictionaryMinMaxImpl(std::shared_ptr<DataType> out_type, 
ScalarAggregateOptions options)
+      : options(std::move(options)),
+        out_type(std::move(out_type)),
+        has_nulls(false),
+        count(0),
+        min(nullptr),
+        max(nullptr) {
+    this->options.min_count = std::max<uint32_t>(1, this->options.min_count);
+  }
+
+  Status Consume(KernelContext*, const ExecSpan& batch) override {
+    if (batch[0].is_scalar()) {
+      return Status::NotImplemented("No min/max implemented for 
DictionaryScalar");
+    }
+
+    DictionaryArray arr(batch[0].array.ToArrayData());
+    this->has_nulls = arr.null_count() > 0;
+    this->count += arr.length() - arr.null_count();
+
+    Datum dict_values(arr.dictionary());
+    ARROW_ASSIGN_OR_RAISE(Datum result, MinMax(std::move(dict_values)));
+    const StructScalar& struct_result =
+        checked_cast<const StructScalar&>(*std::move(result.scalar()));
+    ARROW_ASSIGN_OR_RAISE(auto min_, struct_result.field(FieldRef("min")));
+    ARROW_ASSIGN_OR_RAISE(auto max_, struct_result.field(FieldRef("max")));
+    ARROW_RETURN_NOT_OK(CompareMinMax(std::move(min_), std::move(max_)));
+    return Status::OK();
+  }
+
+  Status MergeFrom(KernelContext*, KernelState&& src) override {
+    const auto& other = checked_cast<const ThisType&>(src);
+
+    ARROW_RETURN_NOT_OK(CompareMinMax(other.min, other.max));
+    this->has_nulls = this->has_nulls || other.has_nulls;
+    this->count += other.count;
+    return Status::OK();
+  }
+
+  Status Finalize(KernelContext*, Datum* out) override {
+    const auto& struct_type = checked_cast<const StructType&>(*out_type);
+    const auto& child_type = struct_type.field(0)->type();
+
+    std::vector<std::shared_ptr<Scalar>> values;
+    // Physical type != result type
+    if ((this->has_nulls && !options.skip_nulls) || (this->count < 
options.min_count) ||
+        this->min == nullptr || this->min->type->id() == Type::NA) {
+      // (null, null)
+      std::shared_ptr<Scalar> null_scalar = MakeNullScalar(child_type);
+      values = {null_scalar, null_scalar};
+    } else {
+      values = {std::move(this->min), std::move(this->max)};
+    }
+
+    out->value = std::make_shared<StructScalar>(std::move(values), 
this->out_type);
+    return Status::OK();
+  }
+
+  ScalarAggregateOptions options;
+  std::shared_ptr<DataType> out_type;
+  bool has_nulls;
+  int64_t count;
+  std::shared_ptr<Scalar> min;
+  std::shared_ptr<Scalar> max;
+
+ private:
+  Status CompareMinMax(std::shared_ptr<Scalar> min_, std::shared_ptr<Scalar> 
max_) {

Review Comment:
   Hi, Thanks for review, have updated



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to