1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
// Copyright 2016 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#if defined(_WIN32) || defined(_WIN64)
#define _CRT_SECURE_NO_WARNINGS 1
#endif
#include "time_zone_libc.h"
#include <chrono>
#include <ctime>
#include <tuple>
#include <utility>
#include "absl/time/internal/cctz/include/cctz/civil_time.h"
#include "absl/time/internal/cctz/include/cctz/time_zone.h"
namespace absl {
namespace time_internal {
namespace cctz {
namespace {
// .first is seconds east of UTC; .second is the time-zone abbreviation.
using OffsetAbbr = std::pair<int, const char*>;
// Defines a function that can be called as follows:
//
// std::tm tm = ...;
// OffsetAbbr off_abbr = get_offset_abbr(tm);
//
#if defined(_WIN32) || defined(_WIN64)
// Uses the globals: '_timezone', '_dstbias' and '_tzname'.
OffsetAbbr get_offset_abbr(const std::tm& tm) {
const bool is_dst = tm.tm_isdst > 0;
const int off = _timezone + (is_dst ? _dstbias : 0);
const char* abbr = _tzname[is_dst];
return {off, abbr};
}
#elif defined(__sun)
// Uses the globals: 'timezone', 'altzone' and 'tzname'.
OffsetAbbr get_offset_abbr(const std::tm& tm) {
const bool is_dst = tm.tm_isdst > 0;
const int off = is_dst ? altzone : timezone;
const char* abbr = tzname[is_dst];
return {off, abbr};
}
#elif defined(__native_client__) || defined(__myriad2__) || \
defined(__EMSCRIPTEN__)
// Uses the globals: 'timezone' and 'tzname'.
OffsetAbbr get_offset_abbr(const std::tm& tm) {
const bool is_dst = tm.tm_isdst > 0;
const int off = _timezone + (is_dst ? 60 * 60 : 0);
const char* abbr = tzname[is_dst];
return {off, abbr};
}
#else
//
// Returns an OffsetAbbr using std::tm fields with various spellings.
//
#if !defined(tm_gmtoff) && !defined(tm_zone)
template <typename T>
OffsetAbbr get_offset_abbr(const T& tm, decltype(&T::tm_gmtoff) = nullptr,
decltype(&T::tm_zone) = nullptr) {
return {tm.tm_gmtoff, tm.tm_zone};
}
#endif // !defined(tm_gmtoff) && !defined(tm_zone)
#if !defined(__tm_gmtoff) && !defined(__tm_zone)
template <typename T>
OffsetAbbr get_offset_abbr(const T& tm, decltype(&T::__tm_gmtoff) = nullptr,
decltype(&T::__tm_zone) = nullptr) {
return {tm.__tm_gmtoff, tm.__tm_zone};
}
#endif // !defined(__tm_gmtoff) && !defined(__tm_zone)
#endif
} // namespace
TimeZoneLibC::TimeZoneLibC(const std::string& name)
: local_(name == "localtime") {}
time_zone::absolute_lookup TimeZoneLibC::BreakTime(
const time_point<sys_seconds>& tp) const {
time_zone::absolute_lookup al;
std::time_t t = ToUnixSeconds(tp);
std::tm tm;
if (local_) {
#if defined(_WIN32) || defined(_WIN64)
localtime_s(&tm, &t);
#else
localtime_r(&t, &tm);
#endif
std::tie(al.offset, al.abbr) = get_offset_abbr(tm);
} else {
#if defined(_WIN32) || defined(_WIN64)
gmtime_s(&tm, &t);
#else
gmtime_r(&t, &tm);
#endif
al.offset = 0;
al.abbr = "UTC";
}
al.cs = civil_second(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec);
al.is_dst = tm.tm_isdst > 0;
return al;
}
time_zone::civil_lookup TimeZoneLibC::MakeTime(const civil_second& cs) const {
time_zone::civil_lookup cl;
std::time_t t;
if (local_) {
// Does not handle SKIPPED/AMBIGUOUS or huge years.
std::tm tm;
tm.tm_year = static_cast<int>(cs.year() - 1900);
tm.tm_mon = cs.month() - 1;
tm.tm_mday = cs.day();
tm.tm_hour = cs.hour();
tm.tm_min = cs.minute();
tm.tm_sec = cs.second();
tm.tm_isdst = -1;
t = std::mktime(&tm);
} else {
t = cs - civil_second();
}
cl.kind = time_zone::civil_lookup::UNIQUE;
cl.pre = cl.trans = cl.post = FromUnixSeconds(t);
return cl;
}
std::string TimeZoneLibC::Description() const {
return local_ ? "localtime" : "UTC";
}
bool TimeZoneLibC::NextTransition(time_point<sys_seconds>* tp) const {
return false;
}
bool TimeZoneLibC::PrevTransition(time_point<sys_seconds>* tp) const {
return false;
}
} // namespace cctz
} // namespace time_internal
} // namespace absl
|
