[Feature](functions) support ignore and nullable functions (#27848)

support ignore and nullable functions

be/src/vec/functions/function_nullables.cpp

@@ -0,0 +1,113 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include "common/status.h"
+#include "vec/columns/column.h"
+#include "vec/columns/column_nullable.h"
+#include "vec/columns/columns_number.h"
+#include "vec/core/block.h"
+#include "vec/core/column_numbers.h"
+#include "vec/core/column_with_type_and_name.h"
+#include "vec/core/types.h"
+#include "vec/data_types/data_type.h"
+#include "vec/data_types/data_type_nullable.h"
+#include "vec/functions/function.h"
+#include "vec/functions/simple_function_factory.h"
+
+namespace doris {
+class FunctionContext;
+} // namespace doris
+
+namespace doris::vectorized {
+
+class FunctionNullable : public IFunction {
+public:
+    static constexpr auto name = "nullable";
+
+    static FunctionPtr create() { return std::make_shared<FunctionNullable>(); }
+
+    String get_name() const override { return name; }
+
+    size_t get_number_of_arguments() const override { return 1; }
+
+    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {
+        return make_nullable(arguments[0]);
+    }
+
+    bool use_default_implementation_for_nulls() const override { return false; }
+
+    // trans nullable column to non-nullable column. If argument is already non-nullable, raise error.
+    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
+                        size_t result, size_t input_rows_count) const override {
+        ColumnPtr& col = block.get_by_position(arguments[0]).column;
+        if (const auto* col_null = check_and_get_column<ColumnNullable>(col); col_null == nullptr) {
+            // not null
+            block.replace_by_position(
+                    result, ColumnNullable::create(col, ColumnBool::create(input_rows_count, 0)));
+        } else { // column is ColumnNullable
+            block.replace_by_position(result, col->clone_resized(input_rows_count));
+        }
+        return Status::OK();
+    }
+};
+
+class FunctionNonNullable : public IFunction {
+public:
+    static constexpr auto name = "non_nullable";
+
+    static FunctionPtr create() { return std::make_shared<FunctionNonNullable>(); }
+
+    String get_name() const override { return name; }
+
+    size_t get_number_of_arguments() const override { return 1; }
+
+    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {
+        return remove_nullable(arguments[0]);
+    }
+
+    bool use_default_implementation_for_nulls() const override { return false; }
+
+    // trans nullable column to non-nullable column. If argument is already non-nullable, raise error.
+    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
+                        size_t result, size_t input_rows_count) const override {
+        auto& data = block.get_by_position(arguments[0]);
+        if (const auto* col_null = check_and_get_column<ColumnNullable>(data.column);
+            col_null == nullptr) // raise error if input is not nullable.
+        {
+            return Status::InvalidArgument(
+                    "Try to use originally non-nullable column {} in nullable's non-nullable "
+                    "convertion.",
+                    data.column->get_name());
+        } else { // column is ColumnNullable
+            if (col_null->has_null()) [[unlikely]] {
+                return Status::InvalidArgument(
+                        "There's NULL value in column {} which is illegal for non_nullable",
+                        data.column->get_name());
+            }
+            const ColumnPtr& nest_col = col_null->get_nested_column_ptr();
+            block.replace_by_position(result, nest_col->clone_resized(nest_col->size()));
+        }
+        return Status::OK();
+    }
+};
+
+void register_function_nullables(SimpleFunctionFactory& factory) {
+    factory.register_function<FunctionNullable>();
+    factory.register_function<FunctionNonNullable>();
+}
+
+} // namespace doris::vectorized