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Diffstat (limited to 'third_party/abseil_cpp/absl/time/internal/cctz/include/cctz/time_zone.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/time/internal/cctz/include/cctz/time_zone.h | 386 |
1 files changed, 0 insertions, 386 deletions
diff --git a/third_party/abseil_cpp/absl/time/internal/cctz/include/cctz/time_zone.h b/third_party/abseil_cpp/absl/time/internal/cctz/include/cctz/time_zone.h deleted file mode 100644 index 5562a37bc8..0000000000 --- a/third_party/abseil_cpp/absl/time/internal/cctz/include/cctz/time_zone.h +++ /dev/null @@ -1,386 +0,0 @@ -// 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 -// -// https://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. - -// A library for translating between absolute times (represented by -// std::chrono::time_points of the std::chrono::system_clock) and civil -// times (represented by cctz::civil_second) using the rules defined by -// a time zone (cctz::time_zone). - -#ifndef ABSL_TIME_INTERNAL_CCTZ_TIME_ZONE_H_ -#define ABSL_TIME_INTERNAL_CCTZ_TIME_ZONE_H_ - -#include <chrono> -#include <cstdint> -#include <string> -#include <utility> - -#include "absl/base/config.h" -#include "absl/time/internal/cctz/include/cctz/civil_time.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace time_internal { -namespace cctz { - -// Convenience aliases. Not intended as public API points. -template <typename D> -using time_point = std::chrono::time_point<std::chrono::system_clock, D>; -using seconds = std::chrono::duration<std::int_fast64_t>; -using sys_seconds = seconds; // Deprecated. Use cctz::seconds instead. - -namespace detail { -template <typename D> -inline std::pair<time_point<seconds>, D> split_seconds( - const time_point<D>& tp) { - auto sec = std::chrono::time_point_cast<seconds>(tp); - auto sub = tp - sec; - if (sub.count() < 0) { - sec -= seconds(1); - sub += seconds(1); - } - return {sec, std::chrono::duration_cast<D>(sub)}; -} -inline std::pair<time_point<seconds>, seconds> split_seconds( - const time_point<seconds>& tp) { - return {tp, seconds::zero()}; -} -} // namespace detail - -// cctz::time_zone is an opaque, small, value-type class representing a -// geo-political region within which particular rules are used for mapping -// between absolute and civil times. Time zones are named using the TZ -// identifiers from the IANA Time Zone Database, such as "America/Los_Angeles" -// or "Australia/Sydney". Time zones are created from factory functions such -// as load_time_zone(). Note: strings like "PST" and "EDT" are not valid TZ -// identifiers. -// -// Example: -// cctz::time_zone utc = cctz::utc_time_zone(); -// cctz::time_zone pst = cctz::fixed_time_zone(std::chrono::hours(-8)); -// cctz::time_zone loc = cctz::local_time_zone(); -// cctz::time_zone lax; -// if (!cctz::load_time_zone("America/Los_Angeles", &lax)) { ... } -// -// See also: -// - http://www.iana.org/time-zones -// - https://en.wikipedia.org/wiki/Zoneinfo -class time_zone { - public: - time_zone() : time_zone(nullptr) {} // Equivalent to UTC - time_zone(const time_zone&) = default; - time_zone& operator=(const time_zone&) = default; - - std::string name() const; - - // An absolute_lookup represents the civil time (cctz::civil_second) within - // this time_zone at the given absolute time (time_point). There are - // additionally a few other fields that may be useful when working with - // older APIs, such as std::tm. - // - // Example: - // const cctz::time_zone tz = ... - // const auto tp = std::chrono::system_clock::now(); - // const cctz::time_zone::absolute_lookup al = tz.lookup(tp); - struct absolute_lookup { - civil_second cs; - // Note: The following fields exist for backward compatibility with older - // APIs. Accessing these fields directly is a sign of imprudent logic in - // the calling code. Modern time-related code should only access this data - // indirectly by way of cctz::format(). - int offset; // civil seconds east of UTC - bool is_dst; // is offset non-standard? - const char* abbr; // time-zone abbreviation (e.g., "PST") - }; - absolute_lookup lookup(const time_point<seconds>& tp) const; - template <typename D> - absolute_lookup lookup(const time_point<D>& tp) const { - return lookup(detail::split_seconds(tp).first); - } - - // A civil_lookup represents the absolute time(s) (time_point) that - // correspond to the given civil time (cctz::civil_second) within this - // time_zone. Usually the given civil time represents a unique instant - // in time, in which case the conversion is unambiguous. However, - // within this time zone, the given civil time may be skipped (e.g., - // during a positive UTC offset shift), or repeated (e.g., during a - // negative UTC offset shift). To account for these possibilities, - // civil_lookup is richer than just a single time_point. - // - // In all cases the civil_lookup::kind enum will indicate the nature - // of the given civil-time argument, and the pre, trans, and post - // members will give the absolute time answers using the pre-transition - // offset, the transition point itself, and the post-transition offset, - // respectively (all three times are equal if kind == UNIQUE). If any - // of these three absolute times is outside the representable range of a - // time_point<seconds> the field is set to its maximum/minimum value. - // - // Example: - // cctz::time_zone lax; - // if (!cctz::load_time_zone("America/Los_Angeles", &lax)) { ... } - // - // // A unique civil time. - // auto jan01 = lax.lookup(cctz::civil_second(2011, 1, 1, 0, 0, 0)); - // // jan01.kind == cctz::time_zone::civil_lookup::UNIQUE - // // jan01.pre is 2011/01/01 00:00:00 -0800 - // // jan01.trans is 2011/01/01 00:00:00 -0800 - // // jan01.post is 2011/01/01 00:00:00 -0800 - // - // // A Spring DST transition, when there is a gap in civil time. - // auto mar13 = lax.lookup(cctz::civil_second(2011, 3, 13, 2, 15, 0)); - // // mar13.kind == cctz::time_zone::civil_lookup::SKIPPED - // // mar13.pre is 2011/03/13 03:15:00 -0700 - // // mar13.trans is 2011/03/13 03:00:00 -0700 - // // mar13.post is 2011/03/13 01:15:00 -0800 - // - // // A Fall DST transition, when civil times are repeated. - // auto nov06 = lax.lookup(cctz::civil_second(2011, 11, 6, 1, 15, 0)); - // // nov06.kind == cctz::time_zone::civil_lookup::REPEATED - // // nov06.pre is 2011/11/06 01:15:00 -0700 - // // nov06.trans is 2011/11/06 01:00:00 -0800 - // // nov06.post is 2011/11/06 01:15:00 -0800 - struct civil_lookup { - enum civil_kind { - UNIQUE, // the civil time was singular (pre == trans == post) - SKIPPED, // the civil time did not exist (pre >= trans > post) - REPEATED, // the civil time was ambiguous (pre < trans <= post) - } kind; - time_point<seconds> pre; // uses the pre-transition offset - time_point<seconds> trans; // instant of civil-offset change - time_point<seconds> post; // uses the post-transition offset - }; - civil_lookup lookup(const civil_second& cs) const; - - // Finds the time of the next/previous offset change in this time zone. - // - // By definition, next_transition(tp, &trans) returns false when tp has - // its maximum value, and prev_transition(tp, &trans) returns false - // when tp has its minimum value. If the zone has no transitions, the - // result will also be false no matter what the argument. - // - // Otherwise, when tp has its minimum value, next_transition(tp, &trans) - // returns true and sets trans to the first recorded transition. Chains - // of calls to next_transition()/prev_transition() will eventually return - // false, but it is unspecified exactly when next_transition(tp, &trans) - // jumps to false, or what time is set by prev_transition(tp, &trans) for - // a very distant tp. - // - // Note: Enumeration of time-zone transitions is for informational purposes - // only. Modern time-related code should not care about when offset changes - // occur. - // - // Example: - // cctz::time_zone nyc; - // if (!cctz::load_time_zone("America/New_York", &nyc)) { ... } - // const auto now = std::chrono::system_clock::now(); - // auto tp = cctz::time_point<cctz::seconds>::min(); - // cctz::time_zone::civil_transition trans; - // while (tp <= now && nyc.next_transition(tp, &trans)) { - // // transition: trans.from -> trans.to - // tp = nyc.lookup(trans.to).trans; - // } - struct civil_transition { - civil_second from; // the civil time we jump from - civil_second to; // the civil time we jump to - }; - bool next_transition(const time_point<seconds>& tp, - civil_transition* trans) const; - template <typename D> - bool next_transition(const time_point<D>& tp, civil_transition* trans) const { - return next_transition(detail::split_seconds(tp).first, trans); - } - bool prev_transition(const time_point<seconds>& tp, - civil_transition* trans) const; - template <typename D> - bool prev_transition(const time_point<D>& tp, civil_transition* trans) const { - return prev_transition(detail::split_seconds(tp).first, trans); - } - - // version() and description() provide additional information about the - // time zone. The content of each of the returned strings is unspecified, - // however, when the IANA Time Zone Database is the underlying data source - // the version() string will be in the familar form (e.g, "2018e") or - // empty when unavailable. - // - // Note: These functions are for informational or testing purposes only. - std::string version() const; // empty when unknown - std::string description() const; - - // Relational operators. - friend bool operator==(time_zone lhs, time_zone rhs) { - return &lhs.effective_impl() == &rhs.effective_impl(); - } - friend bool operator!=(time_zone lhs, time_zone rhs) { return !(lhs == rhs); } - - template <typename H> - friend H AbslHashValue(H h, time_zone tz) { - return H::combine(std::move(h), &tz.effective_impl()); - } - - class Impl; - - private: - explicit time_zone(const Impl* impl) : impl_(impl) {} - const Impl& effective_impl() const; // handles implicit UTC - const Impl* impl_; -}; - -// Loads the named time zone. May perform I/O on the initial load. -// If the name is invalid, or some other kind of error occurs, returns -// false and "*tz" is set to the UTC time zone. -bool load_time_zone(const std::string& name, time_zone* tz); - -// Returns a time_zone representing UTC. Cannot fail. -time_zone utc_time_zone(); - -// Returns a time zone that is a fixed offset (seconds east) from UTC. -// Note: If the absolute value of the offset is greater than 24 hours -// you'll get UTC (i.e., zero offset) instead. -time_zone fixed_time_zone(const seconds& offset); - -// Returns a time zone representing the local time zone. Falls back to UTC. -// Note: local_time_zone.name() may only be something like "localtime". -time_zone local_time_zone(); - -// Returns the civil time (cctz::civil_second) within the given time zone at -// the given absolute time (time_point). Since the additional fields provided -// by the time_zone::absolute_lookup struct should rarely be needed in modern -// code, this convert() function is simpler and should be preferred. -template <typename D> -inline civil_second convert(const time_point<D>& tp, const time_zone& tz) { - return tz.lookup(tp).cs; -} - -// Returns the absolute time (time_point) that corresponds to the given civil -// time within the given time zone. If the civil time is not unique (i.e., if -// it was either repeated or non-existent), then the returned time_point is -// the best estimate that preserves relative order. That is, this function -// guarantees that if cs1 < cs2, then convert(cs1, tz) <= convert(cs2, tz). -inline time_point<seconds> convert(const civil_second& cs, - const time_zone& tz) { - const time_zone::civil_lookup cl = tz.lookup(cs); - if (cl.kind == time_zone::civil_lookup::SKIPPED) return cl.trans; - return cl.pre; -} - -namespace detail { -using femtoseconds = std::chrono::duration<std::int_fast64_t, std::femto>; -std::string format(const std::string&, const time_point<seconds>&, - const femtoseconds&, const time_zone&); -bool parse(const std::string&, const std::string&, const time_zone&, - time_point<seconds>*, femtoseconds*, std::string* err = nullptr); -} // namespace detail - -// Formats the given time_point in the given cctz::time_zone according to -// the provided format string. Uses strftime()-like formatting options, -// with the following extensions: -// -// - %Ez - RFC3339-compatible numeric UTC offset (+hh:mm or -hh:mm) -// - %E*z - Full-resolution numeric UTC offset (+hh:mm:ss or -hh:mm:ss) -// - %E#S - Seconds with # digits of fractional precision -// - %E*S - Seconds with full fractional precision (a literal '*') -// - %E#f - Fractional seconds with # digits of precision -// - %E*f - Fractional seconds with full precision (a literal '*') -// - %E4Y - Four-character years (-999 ... -001, 0000, 0001 ... 9999) -// - %ET - The RFC3339 "date-time" separator "T" -// -// Note that %E0S behaves like %S, and %E0f produces no characters. In -// contrast %E*f always produces at least one digit, which may be '0'. -// -// Note that %Y produces as many characters as it takes to fully render the -// year. A year outside of [-999:9999] when formatted with %E4Y will produce -// more than four characters, just like %Y. -// -// Tip: Format strings should include the UTC offset (e.g., %z, %Ez, or %E*z) -// so that the resulting string uniquely identifies an absolute time. -// -// Example: -// cctz::time_zone lax; -// if (!cctz::load_time_zone("America/Los_Angeles", &lax)) { ... } -// auto tp = cctz::convert(cctz::civil_second(2013, 1, 2, 3, 4, 5), lax); -// std::string f = cctz::format("%H:%M:%S", tp, lax); // "03:04:05" -// f = cctz::format("%H:%M:%E3S", tp, lax); // "03:04:05.000" -template <typename D> -inline std::string format(const std::string& fmt, const time_point<D>& tp, - const time_zone& tz) { - const auto p = detail::split_seconds(tp); - const auto n = std::chrono::duration_cast<detail::femtoseconds>(p.second); - return detail::format(fmt, p.first, n, tz); -} - -// Parses an input string according to the provided format string and -// returns the corresponding time_point. Uses strftime()-like formatting -// options, with the same extensions as cctz::format(), but with the -// exceptions that %E#S is interpreted as %E*S, and %E#f as %E*f. %Ez -// and %E*z also accept the same inputs, which (along with %z) includes -// 'z' and 'Z' as synonyms for +00:00. %ET accepts either 'T' or 't'. -// -// %Y consumes as many numeric characters as it can, so the matching data -// should always be terminated with a non-numeric. %E4Y always consumes -// exactly four characters, including any sign. -// -// Unspecified fields are taken from the default date and time of ... -// -// "1970-01-01 00:00:00.0 +0000" -// -// For example, parsing a string of "15:45" (%H:%M) will return a time_point -// that represents "1970-01-01 15:45:00.0 +0000". -// -// Note that parse() returns time instants, so it makes most sense to parse -// fully-specified date/time strings that include a UTC offset (%z, %Ez, or -// %E*z). -// -// Note also that parse() only heeds the fields year, month, day, hour, -// minute, (fractional) second, and UTC offset. Other fields, like weekday (%a -// or %A), while parsed for syntactic validity, are ignored in the conversion. -// -// Date and time fields that are out-of-range will be treated as errors rather -// than normalizing them like cctz::civil_second() would do. For example, it -// is an error to parse the date "Oct 32, 2013" because 32 is out of range. -// -// A second of ":60" is normalized to ":00" of the following minute with -// fractional seconds discarded. The following table shows how the given -// seconds and subseconds will be parsed: -// -// "59.x" -> 59.x // exact -// "60.x" -> 00.0 // normalized -// "00.x" -> 00.x // exact -// -// Errors are indicated by returning false. -// -// Example: -// const cctz::time_zone tz = ... -// std::chrono::system_clock::time_point tp; -// if (cctz::parse("%Y-%m-%d", "2015-10-09", tz, &tp)) { -// ... -// } -template <typename D> -inline bool parse(const std::string& fmt, const std::string& input, - const time_zone& tz, time_point<D>* tpp) { - time_point<seconds> sec; - detail::femtoseconds fs; - const bool b = detail::parse(fmt, input, tz, &sec, &fs); - if (b) { - // TODO: Return false if unrepresentable as a time_point<D>. - *tpp = std::chrono::time_point_cast<D>(sec); - *tpp += std::chrono::duration_cast<D>(fs); - } - return b; -} - -} // namespace cctz -} // namespace time_internal -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_TIME_INTERNAL_CCTZ_TIME_ZONE_H_ |