/**

* 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_PARSER_H

#define _OB_PARSER_H 1

#include "sql/parser/parse_node.h"

#include "sql/parser/parse_define.h"

#include "lib/allocator/ob_allocator.h"

#include "lib/container/ob_iarray.h"

#include "lib/string/ob_string.h"

#include "lib/charset/ob_charset.h"

#include "sql/parser/ob_parser_utils.h"

namespace oceanbase {

namespace sql {

struct ObMPParseStat {

public:

ObMPParseStat() : parse_fail_(false), fail_ret_(common::OB_SUCCESS), fail_query_idx_(-1)

{}

void reset()

{

parse_fail_ = false;

fail_ret_ = common::OB_SUCCESS;

fail_query_idx_ = -1;

}

bool parse_fail_;

int fail_ret_;

int64_t fail_query_idx_;

};

struct PreParseResult {

common::ObString trace_id_;

};

class ObParser {

public:

explicit ObParser(common::ObIAllocator& allocator, ObSQLMode mode,

common::ObCollationType conn_collation = common::CS_TYPE_UTF8MB4_GENERAL_CI);

virtual ~ObParser();

/// @param queries Note that all three members of ObString is valid, size() is the length

/// of the single statement, length() is the length of remainer statements

static bool is_pl_stmt(const common::ObString& stmt, bool* is_create_func = NULL);

bool is_single_stmt(const common::ObString& stmt);

int split_multiple_stmt(const common::ObString& stmt, common::ObIArray<common::ObString>& queries,

ObMPParseStat& parse_fail, bool is_ret_first_stmt = false);

//@param:

// no_throw_parser_error is used to mark not throw parser error. in the split multi stmt

// situation we will try find ';' delimiter to parser part of string in case of save memory,

// but this maybe parser error and throw error info. However, we will still try parser remain

// string when parse part of string failed, if we throw parse part error info, maybe will let

// someone misunderstand have bug, So, we introduce this mark to decide to throw parser erorr.

// eg: select '123;' from dual; select '123' from dual;

int parse_sql(const common::ObString& stmt, ParseResult& parse_result,

const bool no_throw_parser_error = false);

virtual int parse(const common::ObString& stmt, ParseResult& parse_result, ParseMode mode = STD_MODE,

const bool is_batched_multi_stmt_split_on = false, const bool no_throw_parser_error = false);

virtual void free_result(ParseResult& parse_result);

/**

* @brief The parse interface for prepare

* @param [in] query - To be parsed statement

* @param [in] ns - External namespace

* @param [out] parse_result - parse result

* @retval OB_SUCCESS execute success

* @retval OB_SOME_ERROR special errno need to handle

*

* Compared with general prepare, the external name space is passed in and the redundant process

* that this path will not go to is simplified. The main idea is that in the process of parser,

* whenever you encounter a variable in sql, try to find it in the pl namespace. If you can find

* it, copy the SQL statement before this variable and rewrite this variable as question mark,Also

* record this variable.At the same time, all objects (tables, views, functions) encountered are

* also recorded.

*

*/

int prepare_parse(const common::ObString& query, void* ns, ParseResult& parse_result);

static int pre_parse(const common::ObString& stmt, PreParseResult& res);

private:

static int scan_trace_id(const char* ptr, int64_t len, int32_t& pos, common::ObString& trace_id);

static bool is_trace_id_end(char ch);

static bool is_space(char ch);

// types and constants

private:

// disallow copy

DISALLOW_COPY_AND_ASSIGN(ObParser);

// function members

private:

// data members

common::ObIAllocator* allocator_;

// when sql_mode = "ANSI_QUOTES", Treat " as an identifier quote character

// we don't use it in parser now

ObSQLMode sql_mode_;

common::ObCollationType connection_collation_;

};

} // end namespace sql

} // end namespace oceanbase

#endif /* _OB_PARSER_H */