1 // Copyright 2016 Google Inc. All Rights Reserved.
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
7 // https://www.apache.org/licenses/LICENSE-2.0
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
15 #ifndef ABSL_TIME_INTERNAL_CCTZ_TIME_ZONE_IF_H_
16 #define ABSL_TIME_INTERNAL_CCTZ_TIME_ZONE_IF_H_
23 #include "absl/time/internal/cctz/include/cctz/civil_time.h"
24 #include "absl/time/internal/cctz/include/cctz/time_zone.h"
27 namespace time_internal {
30 // A simple interface used to hide time-zone complexities from time_zone::Impl.
31 // Subclasses implement the functions for civil-time conversions in the zone.
34 // A factory function for TimeZoneIf implementations.
35 static std::unique_ptr<TimeZoneIf> Load(const std::string& name);
37 virtual ~TimeZoneIf();
39 virtual time_zone::absolute_lookup BreakTime(
40 const time_point<seconds>& tp) const = 0;
41 virtual time_zone::civil_lookup MakeTime(
42 const civil_second& cs) const = 0;
44 virtual bool NextTransition(const time_point<seconds>& tp,
45 time_zone::civil_transition* trans) const = 0;
46 virtual bool PrevTransition(const time_point<seconds>& tp,
47 time_zone::civil_transition* trans) const = 0;
49 virtual std::string Version() const = 0;
50 virtual std::string Description() const = 0;
56 // Convert between time_point<seconds> and a count of seconds since the
57 // Unix epoch. We assume that the std::chrono::system_clock and the
58 // Unix clock are second aligned, but not that they share an epoch.
59 inline std::int_fast64_t ToUnixSeconds(const time_point<seconds>& tp) {
60 return (tp - std::chrono::time_point_cast<seconds>(
61 std::chrono::system_clock::from_time_t(0))).count();
63 inline time_point<seconds> FromUnixSeconds(std::int_fast64_t t) {
64 return std::chrono::time_point_cast<seconds>(
65 std::chrono::system_clock::from_time_t(0)) + seconds(t);
69 } // namespace time_internal
72 #endif // ABSL_TIME_INTERNAL_CCTZ_TIME_ZONE_IF_H_