tvl-depot/absl/time/format.cc
Abseil Team cf6ab6bb2b Changes imported from Abseil "staging" branch:
- b527a3e4b36b644ac424e3c525b1cd393f6f6c40 Fix some typos in the usage examples by Jorg Brown <jorg@google.com>
  - 82be4a9adf3bb0ddafc0d46274969c99afffe870 Fix typo in optional.h comment. by Abseil Team <absl-team@google.com>
  - d6ee63bf8fc51fba074c23b33cebc28c808d7f07 Remove internal-only identifiers from code. by Daniel Katz <katzdm@google.com>
  - f9c3ad2f0d73f53b21603638af8b4bed636e79f4 Use easier understandable names for absl::StartsWith and ... by Abseil Team <absl-team@google.com>
  - 7c16c14fefee89c927b8789d6043c4691bcffc9b Add -Wno-missing-prototypes back to the LLVM copts. by Derek Mauro <dmauro@google.com>
  - 2f4b7d2e50c7023240242f1e15db60ccd7e8768d IWYU | absl/strings by Juemin Yang <jueminyang@google.com>
  - a99cbcc1daa34a2d6a2bb26de275e05173cc77e9 IWYU | absl/type by Juemin Yang <jueminyang@google.com>
  - 12e1146d0fc76c071d7e0ebaabb62f0a984fae66 Use LLVM_FLAGS and LLVM_TEST_FLAGS when --compiler=llvm. by Derek Mauro <dmauro@google.com>
  - cd6bea616abda558d0bace5bd77455662a233688 IWYU | absl/debugging by Juemin Yang <jueminyang@google.com>
  - d9a7382e59d46a8581b6b7a31cd5a48bb89326e9 IWYU | absl/synchronization by Juemin Yang <jueminyang@google.com>
  - 07ec7d6d5a4a666f4183c5d0ed9c342baa7b24bc IWYU | absl/numeric by Juemin Yang <jueminyang@google.com>
  - 12bfe40051f4270f8707e191af5652f83f2f750c Remove the RoundTrip{Float,Double}ToBuffer routines from ... by Jorg Brown <jorg@google.com>
  - eeb4fd67c9d97f66cb9475c3c5e51ab132f1c810 Adds conversion functions for converting between absl/tim... by Greg Miller <jgm@google.com>
  - 59a2108d05d4ea85dc5cc11e49b2cd2335d4295a Change Substitute to use %.6g formatting rather than 15/1... by Jorg Brown <jorg@google.com>
  - 394becb48e0fcd161642cdaac5120d32567e0ef8 IWYU | absl/meta by Juemin Yang <jueminyang@google.com>
  - 1e5da6e8da336699b2469dcf6dda025b9b0ec4c9 Rewrite atomic_hook.h to not use std::atomic<T*> under Wi... by Greg Falcon <gfalcon@google.com>

GitOrigin-RevId: b527a3e4b36b644ac424e3c525b1cd393f6f6c40
Change-Id: I14e331d91c956ef045ac7927091a9f179716de0c
2017-09-25 10:12:29 -04:00

140 lines
4.5 KiB
C++

// 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 <string.h>
#include <cctype>
#include <cstdint>
#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<cctz::sys_seconds>;
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<cctz::sys_seconds>(
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(absl-team): Remove once dependencies are removed.
// Functions required to support absl::Time 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