From c2e754829628d1e9b7a16b3389cfdace76950fdf Mon Sep 17 00:00:00 2001 From: misterg Date: Tue, 19 Sep 2017 16:54:40 -0400 Subject: Initial Commit --- absl/time/format.cc | 140 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) create mode 100644 absl/time/format.cc (limited to 'absl/time/format.cc') diff --git a/absl/time/format.cc b/absl/time/format.cc new file mode 100644 index 0000000..c58a886 --- /dev/null +++ b/absl/time/format.cc @@ -0,0 +1,140 @@ +// Copyright 2017 The Abseil Authors. +// +// 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. + +#include +#include +#include + +#include "absl/time/time.h" +#include "cctz/time_zone.h" + +namespace absl { + +extern const char RFC3339_full[] = "%Y-%m-%dT%H:%M:%E*S%Ez"; +extern const char RFC3339_sec[] = "%Y-%m-%dT%H:%M:%S%Ez"; + +extern const char RFC1123_full[] = "%a, %d %b %E4Y %H:%M:%S %z"; +extern const char RFC1123_no_wday[] = "%d %b %E4Y %H:%M:%S %z"; + +namespace { + +const char kInfiniteFutureStr[] = "infinite-future"; +const char kInfinitePastStr[] = "infinite-past"; + +using cctz_sec = cctz::time_point; +using cctz_fem = cctz::detail::femtoseconds; +struct cctz_parts { + cctz_sec sec; + cctz_fem fem; +}; + +inline cctz_sec unix_epoch() { + return std::chrono::time_point_cast( + std::chrono::system_clock::from_time_t(0)); +} + +// Splits a Time into seconds and femtoseconds, which can be used with CCTZ. +// Requires that 't' is finite. See duration.cc for details about rep_hi and +// rep_lo. +cctz_parts Split(absl::Time t) { + const auto d = time_internal::ToUnixDuration(t); + const int64_t rep_hi = time_internal::GetRepHi(d); + const int64_t rep_lo = time_internal::GetRepLo(d); + const auto sec = unix_epoch() + cctz::sys_seconds(rep_hi); + const auto fem = cctz_fem(rep_lo * (1000 * 1000 / 4)); + return {sec, fem}; +} + +// Joins the given seconds and femtoseconds into a Time. See duration.cc for +// details about rep_hi and rep_lo. +absl::Time Join(const cctz_parts& parts) { + const int64_t rep_hi = (parts.sec - unix_epoch()).count(); + const uint32_t rep_lo = parts.fem.count() / (1000 * 1000 / 4); + const auto d = time_internal::MakeDuration(rep_hi, rep_lo); + return time_internal::FromUnixDuration(d); +} + +} // namespace + +std::string FormatTime(const std::string& format, absl::Time t, absl::TimeZone tz) { + if (t == absl::InfiniteFuture()) return kInfiniteFutureStr; + if (t == absl::InfinitePast()) return kInfinitePastStr; + const auto parts = Split(t); + return cctz::detail::format(format, parts.sec, parts.fem, + cctz::time_zone(tz)); +} + +std::string FormatTime(absl::Time t, absl::TimeZone tz) { + return FormatTime(RFC3339_full, t, tz); +} + +std::string FormatTime(absl::Time t) { + return absl::FormatTime(RFC3339_full, t, absl::LocalTimeZone()); +} + +bool ParseTime(const std::string& format, const std::string& input, absl::Time* time, + std::string* err) { + return absl::ParseTime(format, input, absl::UTCTimeZone(), time, err); +} + +// If the input std::string does not contain an explicit UTC offset, interpret +// the fields with respect to the given TimeZone. +bool ParseTime(const std::string& format, const std::string& input, absl::TimeZone tz, + absl::Time* time, std::string* err) { + const char* data = input.c_str(); + while (std::isspace(*data)) ++data; + + size_t inf_size = strlen(kInfiniteFutureStr); + if (strncmp(data, kInfiniteFutureStr, inf_size) == 0) { + const char* new_data = data + inf_size; + while (std::isspace(*new_data)) ++new_data; + if (*new_data == '\0') { + *time = InfiniteFuture(); + return true; + } + } + + inf_size = strlen(kInfinitePastStr); + if (strncmp(data, kInfinitePastStr, inf_size) == 0) { + const char* new_data = data + inf_size; + while (std::isspace(*new_data)) ++new_data; + if (*new_data == '\0') { + *time = InfinitePast(); + return true; + } + } + + std::string error; + cctz_parts parts; + const bool b = cctz::detail::parse(format, input, cctz::time_zone(tz), + &parts.sec, &parts.fem, &error); + if (b) { + *time = Join(parts); + } else if (err != nullptr) { + *err = error; + } + return b; +} + +// TODO(b/63899288) copybara strip once dependencies are removed. +// Functions required to support absl::Time flags. See go/flags. +bool ParseFlag(const std::string& text, absl::Time* t, std::string* error) { + return absl::ParseTime(RFC3339_full, text, absl::UTCTimeZone(), t, error); +} + +std::string UnparseFlag(absl::Time t) { + return absl::FormatTime(RFC3339_full, t, absl::UTCTimeZone()); +} + +} // namespace absl -- cgit v1.2.3