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datetime.hpp
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1 /*********************************************************************/
2 // dar - disk archive - a backup/restoration program
3 // Copyright (C) 2002-2020 Denis Corbin
4 //
5 // This program is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU General Public License
7 // as published by the Free Software Foundation; either version 2
8 // of the License, or (at your option) any later version.
9 //
10 // This program is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 // GNU General Public License for more details.
14 //
15 // You should have received a copy of the GNU General Public License
16 // along with this program; if not, write to the Free Software
17 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 //
19 // to contact the author : http://dar.linux.free.fr/email.html
20 /*********************************************************************/
21
25
26 #ifndef DATETIME_HPP
27 #define DATETIME_HPP
28
29 extern "C"
30 {
31 #if HAVE_SYS_TYPES_H
32 #include <sys/types.h>
33 #endif
34
35 #if HAVE_UTIME_H
36 #include <utime.h>
37 #endif
38
39 #if HAVE_SYS_TIME_H
40 #include <sys/time.h>
41 #endif
42
43 } // end extern "C"
44
45 #include "../my_config.h"
46 #include "infinint.hpp"
47
48 namespace libdar
49 {
52
54 class archive_version;
55 class generic_file;
56
58 class datetime
59 {
60 public:
61 // time units must be sorted: the first is the smallest step, last is the largest increment.
62 // this makes the comparison operators (<, >, <=, >=,...) become naturally defined on that type
63 enum time_unit { tu_nanosecond, tu_microsecond, tu_second };
64
66 datetime(const infinint & value = 0) { val = value; uni = tu_second; };
67
69
73 datetime(time_t second, time_t subsec, time_unit unit);
74
76 datetime(generic_file &x, archive_version ver);
77
78 datetime(const datetime & ref) = default;
79 datetime(datetime && ref) noexcept = default;
80 datetime & operator = (const datetime & ref) = default;
81 datetime & operator = (datetime && ref) noexcept = default;
82 ~datetime() = default;
83
84
85 // comparison operators
86
87 bool operator < (const datetime & ref) const;
88 bool operator == (const datetime & ref) const;
89 bool operator != (const datetime & ref) const { return ! (*this == ref); };
90 bool operator >= (const datetime & ref) const { return ! (*this < ref); };
91 bool operator > (const datetime & ref) const { return ref < *this; };
92 bool operator <= (const datetime & ref) const { return ref >= *this; };
93
94 // arithmetic on time
95 void operator -= (const datetime & ref);
96 void operator += (const datetime & ref);
97 datetime operator - (const datetime & ref) const { datetime tmp(*this); tmp -= ref; return tmp; };
98 datetime operator + (const datetime & ref) const { datetime tmp(*this); tmp += ref; return tmp; };
99
101 bool loose_equal(const datetime & ref) const;
102
104 datetime loose_diff(const datetime & ref) const;
105
107 infinint get_second_value() const { infinint sec, sub; get_value(sec, sub, uni); return sec; };
108
110 infinint get_subsecond_value(time_unit unit) const;
111
113 time_unit get_unit() const { return uni; };
114
116
121 bool get_value(time_t & second, time_t & subsecond, time_unit unit) const;
122
123
125 void dump(generic_file &x) const;
126
128 void read(generic_file &f, archive_version ver);
129
131 bool is_null() const { return val.is_zero(); };
132
134 bool is_integer_second() const { return (uni == tu_second); };
135
137 infinint get_storage_size() const;
138
140 void nullify() { val = 0; uni = tu_second ; };
141
142 private:
143 // the date must not be stored as a single integer
144 // to avoid reducing the possible addressable dates
145 // when compiling using 32 or 64 bits integer in place
146 // of infinint. The fraction cannot handle smaller unit
147 // than nanosecond if using 32 bits integer.
148
149 infinint val; //< the date expressed in the "uni" time unit
150 time_unit uni; //< the time unit used to store the subsecond fraction of the timestamp.
151
153 void reduce_to_largest_unit() const;
154 void get_value(infinint & sec, infinint & sub, time_unit unit) const;
155 void build(const infinint & sec, const infinint & sub, time_unit unit);
156
157 static time_unit min(time_unit a, time_unit b);
158 static time_unit max(time_unit a, time_unit b);
159 static const char time_unit_to_char(time_unit a);
160 static time_unit char_to_time_unit(const char a);
161
163
166 static const infinint & get_scaling_factor(time_unit source, time_unit dest);
167
168 };
169
171 extern archive_version db2archive_version(unsigned char db_version);
172
173
175
176 } // end of namespace
177
178 #endif
libdar::infinint::is_zero
bool is_zero() const
libdar::datetime::nullify
void nullify()
set to null (zero)
Definition: datetime.hpp:140
libdar::datetime::dump
void dump(generic_file &x) const
write down this to file
libdar::datetime::get_second_value
infinint get_second_value() const
return the integer number of second
Definition: datetime.hpp:107
libdar::datetime::reduce_to_largest_unit
void reduce_to_largest_unit() const
reduce the value to the largest unit possible
infinint.hpp
switch module to limitint (32 ou 64 bits integers) or infinint
libdar::infinint
the arbitrary large positive integer class
Definition: real_infinint.hpp:62
libdar::datetime::get_unit
time_unit get_unit() const
returns the time unit used internally to store the subsecond time fraction
Definition: datetime.hpp:113
libdar::datetime::read
void read(generic_file &f, archive_version ver)
read this from file
libdar::archive_version
class archive_version manages the version of the archive format
Definition: archive_version.hpp:47
libdar::datetime::is_null
bool is_null() const
return true if the datetime is exactly January 1st, 1970, 0 h 0 mn 0 s
Definition: datetime.hpp:131
libdar::datetime::loose_equal
bool loose_equal(const datetime &ref) const
equivalent to operator == but if compared object use different time unit, do the comparison rounding ...
libdar::datetime::datetime
datetime(const infinint &value=0)
constructor based on the number of second ellasped since the end of 1969
Definition: datetime.hpp:66
libdar::datetime::is_integer_second
bool is_integer_second() const
return true if the datetime is an integer number of second (subsecond part is zero)
Definition: datetime.hpp:134
libdar::datetime
stores time information
Definition: datetime.hpp:59
libdar::datetime::get_value
bool get_value(time_t &second, time_t &subsecond, time_unit unit) const
return a time as time_t arguments
libdar::generic_file
this is the interface class from which all other data transfer classes inherit
Definition: generic_file.hpp:77
libdar::datetime::loose_diff
datetime loose_diff(const datetime &ref) const
at the difference of operator - provides the difference using the less precise unit used between the ...
libdar::datetime::get_storage_size
infinint get_storage_size() const
return the storage it would require to dump this object
libdar::datetime::get_subsecond_value
infinint get_subsecond_value(time_unit unit) const
return the subsecond time fraction expressed in the given time unit
libdar::datetime::datetime
datetime(generic_file &x, archive_version ver)
constructor reading data dump() into a generic_file
libdar::datetime::get_scaling_factor
static const infinint & get_scaling_factor(time_unit source, time_unit dest)
return the factor between two units
libdar::db2archive_version
archive_version db2archive_version(unsigned char db_version)
converts dar_manager database version to dar archive version in order to properly read time fields
libdar::datetime::datetime
datetime(time_t second, time_t subsec, time_unit unit)
general constructor
libdar
libdar namespace encapsulate all libdar symbols
Definition: archive.hpp:47