oceanbase/src/sql/engine/expr/ob_expr_trim.h

/**
 * 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 _OB_SQL_EXPR_TRIM_H_
#define _OB_SQL_EXPR_TRIM_H_

#include "sql/engine/expr/ob_expr_operator.h"

namespace oceanbase {
namespace common {
class ObExprTypeCtx;
class ObExprCtx;
}  // namespace common
namespace sql {
class ObExprTrim : public ObStringExprOperator {
  public:
  enum TrimType { TYPE_LRTRIM = 0, TYPE_LTRIM = 1, TYPE_RTRIM = 2 };

  explicit ObExprTrim(common::ObIAllocator& alloc);
  explicit ObExprTrim(common::ObIAllocator& alloc, ObExprOperatorType type, const char* name, int32_t param_num);

  virtual ~ObExprTrim();
  static int calc(common::ObObj& result, const int64_t trim_type, const common::ObString& trim_pattern,
      const common::ObString& text, const common::ObObjType& res_type, common::ObExprCtx& expr_ctx);

  static int trim(common::ObString& result, const int64_t trim_type, const common::ObString& trim_pattern,
      const common::ObString& text);

  static int trim2(common::ObString& result, const int64_t trim_type, const common::ObString& trim_pattern,
      const common::ObString& text, const common::ObCollationType& cs_type,
      const common::ObFixedArray<size_t, common::ObIAllocator>&,
      const common::ObFixedArray<size_t, common::ObIAllocator>&);

  virtual int calc_result_typeN(
      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const
  {
    return deduce_result_type(type, types, param_num, type_ctx);
  }

  static int deduce_result_type(
      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx);

  virtual int calc_resultN(
      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;

  virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;

  static int eval_trim(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum);

  // fill ' ' to %buf with specified charset.
  static int fill_default_pattern(char* buf, const int64_t in_len, common::ObCollationType cs_type, int64_t& out_len);

  private:
  // helper func
  static int lrtrim(const common::ObString src, const common::ObString pattern, int32_t& start, int32_t& end);
  static int ltrim(const common::ObString src, const common::ObString pattern, int32_t& start);
  static int rtrim(const common::ObString src, const common::ObString pattern, int32_t& end);

  static int lrtrim2(const common::ObString src, const common::ObString pattern, int32_t& start, int32_t& end);
  static int ltrim2(const common::ObString src, const common::ObString pattern, int32_t& start,
      const common::ObCollationType& cs_type, const common::ObFixedArray<size_t, common::ObIAllocator>&,
      const common::ObFixedArray<size_t, common::ObIAllocator>&);
  static int rtrim2(const common::ObString src, const common::ObString pattern, int32_t& end,
      const common::ObCollationType& cs_type, const common::ObFixedArray<size_t, common::ObIAllocator>&,
      const common::ObFixedArray<size_t, common::ObIAllocator>&);

  // disallow copy
  DISALLOW_COPY_AND_ASSIGN(ObExprTrim);
};

// Ltrim can use ObExprTrim's calc
class ObExprLtrim : public ObExprTrim {
  public:
  explicit ObExprLtrim(common::ObIAllocator& alloc);
  explicit ObExprLtrim(common::ObIAllocator& alloc, ObExprOperatorType type, const char* name, int32_t param_num);
  virtual ~ObExprLtrim();

  virtual int calc_result_type1(ObExprResType& res_type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;

  virtual int calc_result_typeN(
      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const
  {
    return deduce_result_type(type, types, param_num, type_ctx);
  }

  static int deduce_result_type(
      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx);

  virtual int calc_result1(common::ObObj& res_obj, const common::ObObj& obj1, common::ObExprCtx& expr_ctx) const;

  int calc(common::ObObj& res_obj, const common::ObObj& obj1, common::ObExprCtx& expr_ctx, int64_t trim_type_val) const;

  virtual int calc_resultN(
      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;

  static int calc_oracle_mode(common::ObObj& result, const int64_t trim_type, const common::ObString& pattern,
      const common::ObString& text, const common::ObObjType& res_type, common::ObExprCtx& expr_ctx,
      const int64_t param_num, const common::ObCollationType& cs_type);

  virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const override;

  private:
  DISALLOW_COPY_AND_ASSIGN(ObExprLtrim);
};
// Rtrim can use ObExprTrim's calc
class ObExprRtrim : public ObExprLtrim {
  public:
  explicit ObExprRtrim(common::ObIAllocator& alloc);
  virtual ~ObExprRtrim();

  virtual int calc_result1(common::ObObj& res_obj, const common::ObObj& obj1, common::ObExprCtx& expr_ctx) const;

  virtual int calc_resultN(
      common::ObObj& result, const common::ObObj* objs_array, int64_t param_num, common::ObExprCtx& expr_ctx) const;

  virtual int calc_result_type1(ObExprResType& res_type, ObExprResType& type1, common::ObExprTypeCtx& type_ctx) const;

  virtual int calc_result_typeN(
      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx) const
  {
    return ObExprLtrim::deduce_result_type(type, types, param_num, type_ctx);
  }

  static int deduce_result_type(
      ObExprResType& type, ObExprResType* types, int64_t param_num, common::ObExprTypeCtx& type_ctx);

  virtual int cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const
  {
    return ObExprLtrim::cg_expr(op_cg_ctx, raw_expr, rt_expr);
  }

  private:
  DISALLOW_COPY_AND_ASSIGN(ObExprRtrim);
};
}  // namespace sql
}  // namespace oceanbase
#endif /* _OB_SQL_EXPR_TRIM_H_ */