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src/sql/engine/aggregate/ob_scalar_aggregate_op.h

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+/**
+ * Copyright (c) 2021 OceanBase
+ * OceanBase CE is licensed under Mulan PubL v2.
+ * You can use this software according to the terms and conditions of the Mulan PubL v2.
+ * You may obtain a copy of Mulan PubL v2 at:
+ *          http://license.coscl.org.cn/MulanPubL-2.0
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PubL v2 for more details.
+ */
+
+#ifndef OCEANBASE_BASIC_OB_SCALAR_GROUPBY_OP_H_
+#define OCEANBASE_BASIC_OB_SCALAR_GROUPBY_OP_H_
+
+#include "common/row/ob_row_store.h"
+#include "sql/engine/aggregate/ob_groupby_op.h"
+
+namespace oceanbase {
+namespace sql {
+class ObScalarAggregateSpec : public ObGroupBySpec {
+  OB_UNIS_VERSION_V(1);
+
+  public:
+  ObScalarAggregateSpec(common::ObIAllocator& alloc, const ObPhyOperatorType type) : ObGroupBySpec(alloc, type)
+  {}
+
+  private:
+  // disallow copy
+  DISALLOW_COPY_AND_ASSIGN(ObScalarAggregateSpec);
+};
+
+class ObScalarAggregateOp : public ObGroupByOp {
+  public:
+  friend ObAggregateProcessor;
+  ObScalarAggregateOp(ObExecContext& exec_ctx, const ObOpSpec& spec, ObOpInput* input)
+      : ObGroupByOp(exec_ctx, spec, input), started_(false)
+  {}
+
+  virtual int inner_open() override;
+  virtual int inner_close() override;
+  virtual int rescan() override;
+  virtual int switch_iterator() override;
+  virtual int inner_get_next_row() override;
+  virtual void destroy() override;
+  // reset default value of %cur_rownum_ && %rownum_limit_
+  private:
+  // disallow copy
+  DISALLOW_COPY_AND_ASSIGN(ObScalarAggregateOp);
+
+  private:
+  bool started_;
+};
+
+}  // end namespace sql
+}  // end namespace oceanbase
+
+#endif  // OCEANBASE_BASIC_OB_SCALAR_GROUPBY_OP_H_