diff options
Diffstat (limited to 'absl/time/time.h')
-rw-r--r-- | absl/time/time.h | 97 |
1 files changed, 55 insertions, 42 deletions
diff --git a/absl/time/time.h b/absl/time/time.h index 880fc783..c41cb89c 100644 --- a/absl/time/time.h +++ b/absl/time/time.h @@ -81,6 +81,7 @@ constexpr int64_t GetRepHi(Duration d); constexpr uint32_t GetRepLo(Duration d); constexpr Duration MakeDuration(int64_t hi, uint32_t lo); constexpr Duration MakeDuration(int64_t hi, int64_t lo); +inline Duration MakePosDoubleDuration(double n); constexpr int64_t kTicksPerNanosecond = 4; constexpr int64_t kTicksPerSecond = 1000 * 1000 * 1000 * kTicksPerNanosecond; template <std::intmax_t N> @@ -295,6 +296,39 @@ Duration Floor(Duration d, Duration unit); // absl::Duration c = absl::Ceil(d, absl::Microseconds(1)); // 123457us Duration Ceil(Duration d, Duration unit); +// InfiniteDuration() +// +// Returns an infinite `Duration`. To get a `Duration` representing negative +// infinity, use `-InfiniteDuration()`. +// +// Duration arithmetic overflows to +/- infinity and saturates. In general, +// arithmetic with `Duration` infinities is similar to IEEE 754 infinities +// except where IEEE 754 NaN would be involved, in which case +/- +// `InfiniteDuration()` is used in place of a "nan" Duration. +// +// Examples: +// +// constexpr absl::Duration inf = absl::InfiniteDuration(); +// const absl::Duration d = ... any finite duration ... +// +// inf == inf + inf +// inf == inf + d +// inf == inf - inf +// -inf == d - inf +// +// inf == d * 1e100 +// inf == inf / 2 +// 0 == d / inf +// INT64_MAX == inf / d +// +// // Division by zero returns infinity, or INT64_MIN/MAX where appropriate. +// inf == d / 0 +// INT64_MAX == d / absl::ZeroDuration() +// +// The examples involving the `/` operator above also apply to `IDivDuration()` +// and `FDivDuration()`. +constexpr Duration InfiniteDuration(); + // Nanoseconds() // Microseconds() // Milliseconds() @@ -344,7 +378,13 @@ Duration Milliseconds(T n) { } template <typename T, time_internal::EnableIfFloat<T> = 0> Duration Seconds(T n) { - return n * Seconds(1); + if (n >= 0) { + if (n >= std::numeric_limits<int64_t>::max()) return InfiniteDuration(); + return time_internal::MakePosDoubleDuration(n); + } else { + if (n <= std::numeric_limits<int64_t>::min()) return -InfiniteDuration(); + return -time_internal::MakePosDoubleDuration(-n); + } } template <typename T, time_internal::EnableIfFloat<T> = 0> Duration Minutes(T n) { @@ -439,39 +479,6 @@ std::chrono::seconds ToChronoSeconds(Duration d); std::chrono::minutes ToChronoMinutes(Duration d); std::chrono::hours ToChronoHours(Duration d); -// InfiniteDuration() -// -// Returns an infinite `Duration`. To get a `Duration` representing negative -// infinity, use `-InfiniteDuration()`. -// -// Duration arithmetic overflows to +/- infinity and saturates. In general, -// arithmetic with `Duration` infinities is similar to IEEE 754 infinities -// except where IEEE 754 NaN would be involved, in which case +/- -// `InfiniteDuration()` is used in place of a "nan" Duration. -// -// Examples: -// -// constexpr absl::Duration inf = absl::InfiniteDuration(); -// const absl::Duration d = ... any finite duration ... -// -// inf == inf + inf -// inf == inf + d -// inf == inf - inf -// -inf == d - inf -// -// inf == d * 1e100 -// inf == inf / 2 -// 0 == d / inf -// INT64_MAX == inf / d -// -// // Division by zero returns infinity, or INT64_MIN/MAX where appropriate. -// inf == d / 0 -// INT64_MAX == d / absl::ZeroDuration() -// -// The examples involving the `/` operator above also apply to `IDivDuration()` -// and `FDivDuration()`. -constexpr Duration InfiniteDuration(); - // FormatDuration() // // Returns a std::string representing the duration in the form "72h3m0.5s". @@ -492,12 +499,9 @@ inline std::ostream& operator<<(std::ostream& os, Duration d) { // `ZeroDuration()`. Parses "inf" and "-inf" as +/- `InfiniteDuration()`. bool ParseDuration(const std::string& dur_string, Duration* d); -// ParseFlag() -// +// Support for flag values of type Duration. Duration flags must be specified +// in a format that is valid input for absl::ParseDuration(). bool ParseFlag(const std::string& text, Duration* dst, std::string* error); - -// UnparseFlag() -// std::string UnparseFlag(Duration d); // Time @@ -991,9 +995,6 @@ bool ParseTime(const std::string& format, const std::string& input, Time* time, bool ParseTime(const std::string& format, const std::string& input, TimeZone tz, Time* time, std::string* err); -// ParseFlag() -// UnparseFlag() -// // Support for flag values of type Time. Time flags must be specified in a // format that matches absl::RFC3339_full. For example: // @@ -1114,6 +1115,18 @@ constexpr Duration MakeDuration(int64_t hi, int64_t lo) { return MakeDuration(hi, static_cast<uint32_t>(lo)); } +// Make a Duration value from a floating-point number, as long as that number +// is in the range [ 0 .. numeric_limits<int64_t>::max ), that is, as long as +// it's positive and can be converted to int64_t without risk of UB. +inline Duration MakePosDoubleDuration(double n) { + const int64_t int_secs = static_cast<int64_t>(n); + const uint32_t ticks = + static_cast<uint32_t>((n - int_secs) * kTicksPerSecond + 0.5); + return ticks < kTicksPerSecond + ? MakeDuration(int_secs, ticks) + : MakeDuration(int_secs + 1, ticks - kTicksPerSecond); +} + // Creates a normalized Duration from an almost-normalized (sec,ticks) // pair. sec may be positive or negative. ticks must be in the range // -kTicksPerSecond < *ticks < kTicksPerSecond. If ticks is negative it |