MySQL  8.0.27
Source Code Documentation
tztime.h
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1 #ifndef TZTIME_INCLUDED
2 #define TZTIME_INCLUDED
3 
4 #include "my_config.h"
5 /* Copyright (c) 2004, 2021, Oracle and/or its affiliates.
6 
7  This program is free software; you can redistribute it and/or modify
8  it under the terms of the GNU General Public License, version 2.0,
9  as published by the Free Software Foundation.
10 
11  This program is also distributed with certain software (including
12  but not limited to OpenSSL) that is licensed under separate terms,
13  as designated in a particular file or component or in included license
14  documentation. The authors of MySQL hereby grant you an additional
15  permission to link the program and your derivative works with the
16  separately licensed software that they have included with MySQL.
17 
18  This program is distributed in the hope that it will be useful,
19  but WITHOUT ANY WARRANTY; without even the implied warranty of
20  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21  GNU General Public License, version 2.0, for more details.
22 
23  You should have received a copy of the GNU General Public License
24  along with this program; if not, write to the Free Software
25  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
26 
27 #include "my_inttypes.h"
28 
29 #ifdef HAVE_SYS_TIME_H
30 #include <sys/time.h>
31 #endif
32 #ifdef _WIN32
33 #include <winsock2.h>
34 #endif
35 
36 #include "mysql_time.h" // MYSQL_TIME
37 #include "time_zone_common.h" // my_time_t
38 
39 class String;
40 class THD;
41 
42 /**
43  This class represents abstract time zone and provides
44  basic interface for MYSQL_TIME <-> my_time_t conversion.
45  Actual time zones which are specified by DB, or via offset
46  or use system functions are its descendants.
47 */
48 class Time_zone {
49  public:
50  /**
51  Enum to identify the type of the timezone
52  */
53  enum tz_type { TZ_DB = 1, TZ_OFFSET = 2, TZ_SYSTEM = 3, TZ_UTC = 4 };
54 
55  /**
56  Converts local time in broken down MYSQL_TIME representation to
57  my_time_t (UTC seconds since Epoch) represenation.
58  Returns 0 in case of error. Sets in_dst_time_gap to true if date provided
59  falls into spring time-gap (or lefts it untouched otherwise).
60  */
62  bool *in_dst_time_gap) const = 0;
63  /**
64  Converts time in my_time_t representation to local time in
65  broken down MYSQL_TIME representation.
66  */
67  virtual void gmt_sec_to_TIME(MYSQL_TIME *tmp, my_time_t t) const = 0;
68  /**
69  Comverts "struct timeval" to local time in
70  broken down MYSQL_TIME represendation.
71  */
72  void gmt_sec_to_TIME(MYSQL_TIME *tmp, struct timeval tv) const {
73  gmt_sec_to_TIME(tmp, (my_time_t)tv.tv_sec);
74  tmp->second_part = tv.tv_usec;
75  }
76  /**
77  Because of constness of String returned by get_name() time zone name
78  have to be already zeroended to be able to use String::ptr() instead
79  of c_ptr().
80  */
81  virtual const String *get_name() const = 0;
82  /**
83  *Returns the timezone type set.
84  */
85  virtual tz_type get_timezone_type() const = 0;
86  /**
87  Returns the offset set for a Timezone offset.
88  This function has to be invoked ONLY when TZ_OFFSET is set.
89  */
90  virtual long get_timezone_offset() const = 0;
91  /**
92  We need this only for surpressing warnings, objects of this type are
93  allocated on MEM_ROOT and should not require destruction.
94  */
95  virtual ~Time_zone() = default;
96 
97  protected:
98  static inline void adjust_leap_second(MYSQL_TIME *t);
99 };
100 
101 extern Time_zone *my_tz_UTC;
102 extern Time_zone *my_tz_SYSTEM;
103 extern Time_zone *my_tz_OFFSET0;
104 extern Time_zone *my_tz_find(THD *thd, const String *name);
105 extern bool my_tz_init(THD *org_thd, const char *default_tzname,
106  bool bootstrap);
107 extern void my_tz_free();
109 
112 my_time_t use_input_time_zone(const MYSQL_TIME *input, bool *in_dst_time_gap);
113 void sec_to_TIME(MYSQL_TIME *tmp, my_time_t t, int64 offset);
114 
115 /**
116  Number of elements in table list produced by my_tz_get_table_list()
117  (this table list contains tables which are needed for dynamical loading
118  of time zone descriptions). Actually it is imlementation detail that
119  should not be used anywhere outside of tztime.h and tztime.cc.
120 */
121 
122 static const int MY_TZ_TABLES_COUNT = 4;
123 
124 #endif /* TZTIME_INCLUDED */
Using this class is fraught with peril, and you need to be very careful when doing so.
Definition: sql_string.h:165
For each client connection we create a separate thread with THD serving as a thread/connection descri...
Definition: sql_class.h:821
This class represents abstract time zone and provides basic interface for MYSQL_TIME <-> my_time_t co...
Definition: tztime.h:48
virtual ~Time_zone()=default
We need this only for surpressing warnings, objects of this type are allocated on MEM_ROOT and should...
static void adjust_leap_second(MYSQL_TIME *t)
Convert leap seconds into non-leap.
Definition: tztime.cc:1856
virtual my_time_t TIME_to_gmt_sec(const MYSQL_TIME *t, bool *in_dst_time_gap) const =0
Converts local time in broken down MYSQL_TIME representation to my_time_t (UTC seconds since Epoch) r...
void gmt_sec_to_TIME(MYSQL_TIME *tmp, struct timeval tv) const
Comverts "struct timeval" to local time in broken down MYSQL_TIME represendation.
Definition: tztime.h:72
virtual void gmt_sec_to_TIME(MYSQL_TIME *tmp, my_time_t t) const =0
Converts time in my_time_t representation to local time in broken down MYSQL_TIME representation.
virtual const String * get_name() const =0
Because of constness of String returned by get_name() time zone name have to be already zeroended to ...
tz_type
Enum to identify the type of the timezone.
Definition: tztime.h:53
@ TZ_UTC
Definition: tztime.h:53
@ TZ_SYSTEM
Definition: tztime.h:53
@ TZ_DB
Definition: tztime.h:53
@ TZ_OFFSET
Definition: tztime.h:53
virtual long get_timezone_offset() const =0
Returns the offset set for a Timezone offset.
virtual tz_type get_timezone_type() const =0
Returns the timezone type set.
Some integer typedefs for easier portability.
int64_t int64
Definition: my_inttypes.h:67
[] long int my_time_t
Portable time_t replacement.
Time declarations shared between the server and client API: you should not add anything to this heade...
Definition: bootstrap.cc:69
case opt name
Definition: sslopt-case.h:32
Definition: mysql_time.h:81
unsigned long second_part
microseconds
Definition: mysql_time.h:83
Include file for Sun RPC to compile out of the box.
Contains common functionality shared between mysqld and mysql_tz_info_to_sql.
my_time_t use_input_time_zone(const MYSQL_TIME *input, bool *in_dst_time_gap)
void sec_to_TIME(MYSQL_TIME *tmp, my_time_t t, int64 offset)
Definition: tztime.cc:131
bool my_tz_init(THD *org_thd, const char *default_tzname, bool bootstrap)
Definition: tztime.cc:1175
Time_zone * my_tz_find(THD *thd, const String *name)
Get Time_zone object for specified time zone.
Definition: tztime.cc:1793
bool convert_time_zone_displacement(const Time_zone *tz, MYSQL_TIME *mt)
Converts a date/time value with time zone to the corresponding date/time value without time zone,...
Definition: tztime.cc:618
Time_zone * my_tz_UTC
Definition: tztime.cc:1025
void my_tz_free()
Definition: tztime.cc:1343
bool check_time_zone_convertibility(const MYSQL_TIME &mt)
Checks that this temporal value can be converted from its specified time zone (if any) to the current...
Definition: tztime.cc:589
static const int MY_TZ_TABLES_COUNT
Number of elements in table list produced by my_tz_get_table_list() (this table list contains tables ...
Definition: tztime.h:122
Time_zone * my_tz_OFFSET0
Definition: tztime.cc:1024
my_time_t sec_since_epoch_TIME(MYSQL_TIME *t)
Time_zone * my_tz_SYSTEM
Definition: tztime.cc:1026