blob: 4005fb704cf64fec5fc9374203253f17fe1a416e [file] [log] [blame]
// 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
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
#include <string.h>
#include <cctype>
#include <cstdint>
#include "absl/strings/match.h"
#include "absl/strings/string_view.h"
#include "absl/time/internal/cctz/include/cctz/time_zone.h"
#include "absl/time/time.h"
namespace cctz = absl::time_internal::cctz;
namespace absl {
ABSL_DLL extern const char RFC3339_full[] = "%Y-%m-%d%ET%H:%M:%E*S%Ez";
ABSL_DLL extern const char RFC3339_sec[] = "%Y-%m-%d%ET%H:%M:%S%Ez";
ABSL_DLL extern const char RFC1123_full[] = "%a, %d %b %E4Y %H:%M:%S %z";
ABSL_DLL extern const char RFC1123_no_wday[] = "%d %b %E4Y %H:%M:%S %z";
namespace {
const char kInfiniteFutureStr[] = "infinite-future";
const char kInfinitePastStr[] = "infinite-past";
struct cctz_parts {
cctz::time_point<cctz::seconds> sec;
cctz::detail::femtoseconds fem;
inline cctz::time_point<cctz::seconds> unix_epoch() {
return std::chrono::time_point_cast<cctz::seconds>(
// Splits a Time into seconds and femtoseconds, which can be used with CCTZ.
// Requires that 't' is finite. See 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::seconds(rep_hi);
const auto fem = cctz::detail::femtoseconds(rep_lo * (1000 * 1000 / 4));
return {sec, fem};
// Joins the given seconds and femtoseconds into a Time. See 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(absl::string_view format, absl::Time t,
absl::TimeZone tz) {
if (t == absl::InfiniteFuture()) return std::string(kInfiniteFutureStr);
if (t == absl::InfinitePast()) return std::string(kInfinitePastStr);
const auto parts = Split(t);
return cctz::detail::format(std::string(format), parts.sec, parts.fem,
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(absl::string_view format, absl::string_view input,
absl::Time* time, std::string* err) {
return absl::ParseTime(format, input, absl::UTCTimeZone(), time, err);
// If the input string does not contain an explicit UTC offset, interpret
// the fields with respect to the given TimeZone.
bool ParseTime(absl::string_view format, absl::string_view input,
absl::TimeZone tz, absl::Time* time, std::string* err) {
auto strip_leading_space = [](absl::string_view* sv) {
while (!sv->empty()) {
if (!std::isspace(sv->front())) return;
// Portable toolchains means we don't get nice constexpr here.
struct Literal {
const char* name;
size_t size;
absl::Time value;
static Literal literals[] = {
{kInfiniteFutureStr, strlen(kInfiniteFutureStr), InfiniteFuture()},
{kInfinitePastStr, strlen(kInfinitePastStr), InfinitePast()},
for (const auto& lit : literals) {
if (absl::StartsWith(input, absl::string_view(, lit.size))) {
absl::string_view tail = input;
if (tail.empty()) {
*time = lit.value;
return true;
std::string error;
cctz_parts parts;
const bool b =
cctz::detail::parse(std::string(format), std::string(input),
cctz::time_zone(tz), &parts.sec, &parts.fem, &error);
if (b) {
*time = Join(parts);
} else if (err != nullptr) {
*err = error;
return b;
// Functions required to support absl::Time flags.
bool AbslParseFlag(absl::string_view text, absl::Time* t, std::string* error) {
return absl::ParseTime(RFC3339_full, text, absl::UTCTimeZone(), t, error);
std::string AbslUnparseFlag(absl::Time t) {
return absl::FormatTime(RFC3339_full, t, absl::UTCTimeZone());
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