sql_time.h

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/* Copyright (c) 2006, 2019, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#ifndef SQL_TIME_INCLUDED
#define SQL_TIME_INCLUDED

/**
  @ingroup SQL_TIME
  @{

  @file sql/sql_time.h

  Interface for server time utilities.
*/

#include "my_config.h"

#include <stddef.h>
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <sys/types.h>

#include "field_types.h"  // enum_field_types
#include "lex_string.h"
#include "m_ctype.h"
#include "my_dbug.h"
#include "my_inttypes.h"
#include "my_time.h"
#include "mysql_time.h"    /* enum_mysql_timestamp_type */
#include "sql/sql_error.h" /* Sql_condition */
#include "sql_string.h"

class THD;
class my_decimal;

/**
   Representation of time formats.
 */
struct Date_time_format {
  uchar positions[8];
  LEX_CSTRING format;
};

/**
   Collection of strings describing date/time formats.
 */
struct Known_date_time_format {
  const char *format_name;
  const char *date_format;
  const char *datetime_format;
  const char *time_format;
};

my_time_t TIME_to_timestamp(THD *thd, const MYSQL_TIME *t, bool *not_exist);
bool datetime_with_no_zero_in_date_to_timeval(THD *thd, const MYSQL_TIME *t,
                                              struct timeval *tm,
                                              int *warnings);
bool datetime_to_timeval(THD *thd, const MYSQL_TIME *t, struct timeval *tm,
                         int *warnings);
bool str_to_datetime_with_warn(String *str, MYSQL_TIME *l_time,
                               my_time_flags_t flags);
bool my_decimal_to_datetime_with_warn(const my_decimal *decimal,
                                      MYSQL_TIME *ltime, my_time_flags_t flags);
bool my_double_to_datetime_with_warn(double nr, MYSQL_TIME *ltime,
                                     my_time_flags_t flags);
bool my_longlong_to_datetime_with_warn(longlong nr, MYSQL_TIME *ltime,
                                       my_time_flags_t flags);
bool my_decimal_to_time_with_warn(const my_decimal *decimal, MYSQL_TIME *ltime);
bool my_double_to_time_with_warn(double nr, MYSQL_TIME *ltime);
bool my_longlong_to_time_with_warn(longlong nr, MYSQL_TIME *ltime);
bool str_to_time_with_warn(String *str, MYSQL_TIME *l_time);
void time_to_datetime(THD *thd, const MYSQL_TIME *tm, MYSQL_TIME *dt);

bool make_truncated_value_warning(THD *thd,
                                  Sql_condition::enum_severity_level level,
                                  const ErrConvString &val,
                                  enum_mysql_timestamp_type time_type,
                                  const char *field_name);

const char *get_date_time_format_str(const Known_date_time_format *format,
                                     enum_mysql_timestamp_type type);
void make_date(const Date_time_format *format, const MYSQL_TIME *l_time,
               String *str);
void make_time(const Date_time_format *format, const MYSQL_TIME *l_time,
               String *str, uint dec);
void make_datetime(const Date_time_format *format, const MYSQL_TIME *l_time,
                   String *str, uint dec);
bool my_TIME_to_str(const MYSQL_TIME *ltime, String *str, uint dec);

void propagate_datetime_overflow_helper(THD *thd, int *warnings);

/**
   Wrapper function which will propagate any DATETIME_OVERFLOW warnings
   to the THD. Overload for the case where a warnings bitset already
   exists which can be inspected before the value of the mysys
   function is passed on.

   @param thd Thread context
   @param warnings bitset used mysys function
   @param t value mysys function which is passed on
   @retval t
 */
template <class T>
inline T propagate_datetime_overflow(THD *thd, int *warnings, T t) {
  propagate_datetime_overflow_helper(thd, warnings);
  return t;
}

/**
   Wrapper function which will propagate any DATETIME_OVERFLOW warnings
   to the THD. Overload for the case when a warnings bitset must be
   created and inspected to call a mysys function. The mysys function
   must be invoked by the closure argument which invoked with a
   pointer to the warnings bitset as argument.

   @param thd Thread context
   @param clos closure to call with empty warnings bitset
   @return return value of closure
 */
template <class CLOS>
inline auto propagate_datetime_overflow(THD *thd, CLOS &&clos) {
  int warnings = 0;
  return propagate_datetime_overflow(thd, &warnings, clos(&warnings));
}

bool date_add_interval_with_warn(THD *, MYSQL_TIME *ltime,
                                 interval_type int_type, Interval interval);

bool str_to_time(const CHARSET_INFO *cs, const char *str, size_t length,
                 MYSQL_TIME *l_time, my_time_flags_t flags,
                 MYSQL_TIME_STATUS *status);

/**
   Converts a time String value to MYSQL_TIME. Forwards to the version
   taking an explicit charset, c-string and length.

   @return False on success, true on error.
 */
inline bool str_to_time(const String *str, MYSQL_TIME *ltime,
                        my_time_flags_t flags, MYSQL_TIME_STATUS *status) {
  return str_to_time(str->charset(), str->ptr(), str->length(), ltime, flags,
                     status);
}

bool str_to_datetime(const CHARSET_INFO *cs, const char *str, size_t length,
                     MYSQL_TIME *l_time, my_time_flags_t flags,
                     MYSQL_TIME_STATUS *status);

/**
   Converts a datetime String value to MYSQL_TIME. Forwards to the
   version taking an explicit charset, c-string and length.

   @return False on success, true on error.
*/
inline bool str_to_datetime(const String *str, MYSQL_TIME *ltime,
                            my_time_flags_t flags, MYSQL_TIME_STATUS *status) {
  return str_to_datetime(str->charset(), str->ptr(), str->length(), ltime,
                         flags, status);
}

extern const LEX_CSTRING interval_type_to_name[];

my_decimal *my_decimal_from_datetime_packed(my_decimal *dec,
                                            enum enum_field_types type,
                                            longlong packed_value);

/**
   Return the timstamp value corresponding the field type passed as argument.

   @param type field type
   @return corresponding timestamp type
 */
inline enum_mysql_timestamp_type field_type_to_timestamp_type(
    enum enum_field_types type) {
  switch (type) {
    case MYSQL_TYPE_TIME:
      return MYSQL_TIMESTAMP_TIME;
    case MYSQL_TYPE_DATE:
      return MYSQL_TIMESTAMP_DATE;
    case MYSQL_TYPE_TIMESTAMP:
    case MYSQL_TYPE_DATETIME:
      return MYSQL_TIMESTAMP_DATETIME;
    default:
      return MYSQL_TIMESTAMP_NONE;
  }
}

/**
  This function gets GMT time and adds value of time_zone to get
  the local time. This function is used when server wants a timestamp
  value from dictionary system.

  @return time converted to local time
*/

ulonglong gmt_time_to_local_time(ulonglong time);

/**
  In lieu of a proper constructor for the C struct MYSQL_TIME, this method
  initializes the struct.
*/
MYSQL_TIME my_time_set(uint y, uint m, uint d, uint h, uint mi, uint s,
                       unsigned long ms, bool negative,
                       enum_mysql_timestamp_type type);
/**
  Return the number of significant second fraction decimals in ts, e.g.
  for ts->second_part == 120300, return 4.

  @param ts the time value for which we wnat the number of decmals
  @return the number of decimals
*/
uint actual_decimals(const MYSQL_TIME *ts);

/**
  For a time fraction with a given number of decimals, return maximum fraction,
  if any, can be are present in a time value. For example, if 2 decimals are
  specified, return 990000. If none, 0.

  @param decimals the number of decimals
  @return the maximum fraction
*/
size_t max_fraction(uint decimals);

/**
   @} (end of ingroup SQL_TIME)
*/

#endif /* SQL_TIME_INCLUDED */