tvl-depot/absl/time/duration.cc

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// 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.
// The implementation of the absl::Duration class, which is declared in
// //absl/time.h. This class behaves like a numeric type; it has no public
// methods and is used only through the operators defined here.
//
// Implementation notes:
//
// An absl::Duration is represented as
//
// rep_hi_ : (int64_t) Whole seconds
// rep_lo_ : (uint32_t) Fractions of a second
//
// The seconds value (rep_hi_) may be positive or negative as appropriate.
// The fractional seconds (rep_lo_) is always a positive offset from rep_hi_.
// The API for Duration guarantees at least nanosecond resolution, which
// means rep_lo_ could have a max value of 1B - 1 if it stored nanoseconds.
// However, to utilize more of the available 32 bits of space in rep_lo_,
// we instead store quarters of a nanosecond in rep_lo_ resulting in a max
// value of 4B - 1. This allows us to correctly handle calculations like
// 0.5 nanos + 0.5 nanos = 1 nano. The following example shows the actual
// Duration rep using quarters of a nanosecond.
//
// 2.5 sec = {rep_hi_=2, rep_lo_=2000000000} // lo = 4 * 500000000
// -2.5 sec = {rep_hi_=-3, rep_lo_=2000000000}
//
// Infinite durations are represented as Durations with the rep_lo_ field set
// to all 1s.
//
// +InfiniteDuration:
// rep_hi_ : kint64max
// rep_lo_ : ~0U
//
// -InfiniteDuration:
// rep_hi_ : kint64min
// rep_lo_ : ~0U
//
// Arithmetic overflows/underflows to +/- infinity and saturates.
#include <algorithm>
#include <cassert>
#include <cctype>
#include <cerrno>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <functional>
#include <limits>
#include <string>
#include "absl/base/casts.h"
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#include "absl/numeric/int128.h"
#include "absl/time/time.h"
namespace absl {
namespace {
using time_internal::kTicksPerNanosecond;
using time_internal::kTicksPerSecond;
constexpr int64_t kint64max = std::numeric_limits<int64_t>::max();
constexpr int64_t kint64min = std::numeric_limits<int64_t>::min();
// Can't use std::isinfinite() because it doesn't exist on windows.
inline bool IsFinite(double d) {
return d != std::numeric_limits<double>::infinity() &&
d != -std::numeric_limits<double>::infinity();
}
// Can't use std::round() because it is only available in C++11.
// Note that we ignore the possibility of floating-point over/underflow.
template <typename Double>
inline double Round(Double d) {
return d < 0 ? std::ceil(d - 0.5) : std::floor(d + 0.5);
}
// *sec may be positive or negative. *ticks must be in the range
// -kTicksPerSecond < *ticks < kTicksPerSecond. If *ticks is negative it
// will be normalized to a positive value by adjusting *sec accordingly.
inline void NormalizeTicks(int64_t* sec, int64_t* ticks) {
if (*ticks < 0) {
--*sec;
*ticks += kTicksPerSecond;
}
}
// Makes a uint128 from the absolute value of the given scalar.
inline uint128 MakeU128(int64_t a) {
uint128 u128 = 0;
if (a < 0) {
++u128;
++a; // Makes it safe to negate 'a'
a = -a;
}
u128 += static_cast<uint64_t>(a);
return u128;
}
// Makes a uint128 count of ticks out of the absolute value of the Duration.
inline uint128 MakeU128Ticks(Duration d) {
int64_t rep_hi = time_internal::GetRepHi(d);
uint32_t rep_lo = time_internal::GetRepLo(d);
if (rep_hi < 0) {
++rep_hi;
rep_hi = -rep_hi;
rep_lo = kTicksPerSecond - rep_lo;
}
uint128 u128 = static_cast<uint64_t>(rep_hi);
u128 *= static_cast<uint64_t>(kTicksPerSecond);
u128 += rep_lo;
return u128;
}
// Breaks a uint128 of ticks into a Duration.
inline Duration MakeDurationFromU128(uint128 u128, bool is_neg) {
int64_t rep_hi;
uint32_t rep_lo;
const uint64_t h64 = Uint128High64(u128);
const uint64_t l64 = Uint128Low64(u128);
if (h64 == 0) { // fastpath
const uint64_t hi = l64 / kTicksPerSecond;
rep_hi = static_cast<int64_t>(hi);
rep_lo = static_cast<uint32_t>(l64 - hi * kTicksPerSecond);
} else {
// kMaxRepHi64 is the high 64 bits of (2^63 * kTicksPerSecond).
// Any positive tick count whose high 64 bits are >= kMaxRepHi64
// is not representable as a Duration. A negative tick count can
// have its high 64 bits == kMaxRepHi64 but only when the low 64
// bits are all zero, otherwise it is not representable either.
const uint64_t kMaxRepHi64 = 0x77359400UL;
if (h64 >= kMaxRepHi64) {
if (is_neg && h64 == kMaxRepHi64 && l64 == 0) {
// Avoid trying to represent -kint64min below.
return time_internal::MakeDuration(kint64min);
}
return is_neg ? -InfiniteDuration() : InfiniteDuration();
}
const uint128 kTicksPerSecond128 = static_cast<uint64_t>(kTicksPerSecond);
const uint128 hi = u128 / kTicksPerSecond128;
rep_hi = static_cast<int64_t>(Uint128Low64(hi));
rep_lo =
static_cast<uint32_t>(Uint128Low64(u128 - hi * kTicksPerSecond128));
}
if (is_neg) {
rep_hi = -rep_hi;
if (rep_lo != 0) {
--rep_hi;
rep_lo = kTicksPerSecond - rep_lo;
}
}
return time_internal::MakeDuration(rep_hi, rep_lo);
}
// Convert between int64_t and uint64_t, preserving representation. This
// allows us to do arithmetic in the unsigned domain, where overflow has
// well-defined behavior. See operator+=() and operator-=().
//
// C99 7.20.1.1.1, as referenced by C++11 18.4.1.2, says, "The typedef
// name intN_t designates a signed integer type with width N, no padding
// bits, and a two's complement representation." So, we can convert to
// and from the corresponding uint64_t value using a bit cast.
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inline uint64_t EncodeTwosComp(int64_t v) {
return absl::bit_cast<uint64_t>(v);
}
inline int64_t DecodeTwosComp(uint64_t v) { return absl::bit_cast<int64_t>(v); }
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// Note: The overflow detection in this function is done using greater/less *or
// equal* because kint64max/min is too large to be represented exactly in a
// double (which only has 53 bits of precision). In order to avoid assigning to
// rep->hi a double value that is too large for an int64_t (and therefore is
// undefined), we must consider computations that equal kint64max/min as a
// double as overflow cases.
inline bool SafeAddRepHi(double a_hi, double b_hi, Duration* d) {
double c = a_hi + b_hi;
if (c >= kint64max) {
*d = InfiniteDuration();
return false;
}
if (c <= kint64min) {
*d = -InfiniteDuration();
return false;
}
*d = time_internal::MakeDuration(c, time_internal::GetRepLo(*d));
return true;
}
// A functor that's similar to std::multiplies<T>, except this returns the max
// T value instead of overflowing. This is only defined for uint128.
template <typename Ignored>
struct SafeMultiply {
uint128 operator()(uint128 a, uint128 b) const {
// b hi is always zero because it originated as an int64_t.
assert(Uint128High64(b) == 0);
// Fastpath to avoid the expensive overflow check with division.
if (Uint128High64(a) == 0) {
return (((Uint128Low64(a) | Uint128Low64(b)) >> 32) == 0)
? static_cast<uint128>(Uint128Low64(a) * Uint128Low64(b))
: a * b;
}
return b == 0 ? b : (a > kuint128max / b) ? kuint128max : a * b;
}
};
// Scales (i.e., multiplies or divides, depending on the Operation template)
// the Duration d by the int64_t r.
template <template <typename> class Operation>
inline Duration ScaleFixed(Duration d, int64_t r) {
const uint128 a = MakeU128Ticks(d);
const uint128 b = MakeU128(r);
const uint128 q = Operation<uint128>()(a, b);
const bool is_neg = (time_internal::GetRepHi(d) < 0) != (r < 0);
return MakeDurationFromU128(q, is_neg);
}
// Scales (i.e., multiplies or divides, depending on the Operation template)
// the Duration d by the double r.
template <template <typename> class Operation>
inline Duration ScaleDouble(Duration d, double r) {
Operation<double> op;
double hi_doub = op(time_internal::GetRepHi(d), r);
double lo_doub = op(time_internal::GetRepLo(d), r);
double hi_int = 0;
double hi_frac = std::modf(hi_doub, &hi_int);
// Moves hi's fractional bits to lo.
lo_doub /= kTicksPerSecond;
lo_doub += hi_frac;
double lo_int = 0;
double lo_frac = std::modf(lo_doub, &lo_int);
// Rolls lo into hi if necessary.
int64_t lo64 = Round(lo_frac * kTicksPerSecond);
Duration ans;
if (!SafeAddRepHi(hi_int, lo_int, &ans)) return ans;
int64_t hi64 = time_internal::GetRepHi(ans);
if (!SafeAddRepHi(hi64, lo64 / kTicksPerSecond, &ans)) return ans;
hi64 = time_internal::GetRepHi(ans);
lo64 %= kTicksPerSecond;
NormalizeTicks(&hi64, &lo64);
return time_internal::MakeDuration(hi64, lo64);
}
// Tries to divide num by den as fast as possible by looking for common, easy
// cases. If the division was done, the quotient is in *q and the remainder is
// in *rem and true will be returned.
inline bool IDivFastPath(const Duration num, const Duration den, int64_t* q,
Duration* rem) {
// Bail if num or den is an infinity.
if (time_internal::IsInfiniteDuration(num) ||
time_internal::IsInfiniteDuration(den))
return false;
int64_t num_hi = time_internal::GetRepHi(num);
uint32_t num_lo = time_internal::GetRepLo(num);
int64_t den_hi = time_internal::GetRepHi(den);
uint32_t den_lo = time_internal::GetRepLo(den);
if (den_hi == 0 && den_lo == kTicksPerNanosecond) {
// Dividing by 1ns
if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000000000) {
*q = num_hi * 1000000000 + num_lo / kTicksPerNanosecond;
*rem = time_internal::MakeDuration(0, num_lo % den_lo);
return true;
}
} else if (den_hi == 0 && den_lo == 100 * kTicksPerNanosecond) {
// Dividing by 100ns (common when converting to Universal time)
if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 10000000) {
*q = num_hi * 10000000 + num_lo / (100 * kTicksPerNanosecond);
*rem = time_internal::MakeDuration(0, num_lo % den_lo);
return true;
}
} else if (den_hi == 0 && den_lo == 1000 * kTicksPerNanosecond) {
// Dividing by 1us
if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000000) {
*q = num_hi * 1000000 + num_lo / (1000 * kTicksPerNanosecond);
*rem = time_internal::MakeDuration(0, num_lo % den_lo);
return true;
}
} else if (den_hi == 0 && den_lo == 1000000 * kTicksPerNanosecond) {
// Dividing by 1ms
if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000) {
*q = num_hi * 1000 + num_lo / (1000000 * kTicksPerNanosecond);
*rem = time_internal::MakeDuration(0, num_lo % den_lo);
return true;
}
} else if (den_hi > 0 && den_lo == 0) {
// Dividing by positive multiple of 1s
if (num_hi >= 0) {
if (den_hi == 1) {
*q = num_hi;
*rem = time_internal::MakeDuration(0, num_lo);
return true;
}
*q = num_hi / den_hi;
*rem = time_internal::MakeDuration(num_hi % den_hi, num_lo);
return true;
}
if (num_lo != 0) {
num_hi += 1;
}
int64_t quotient = num_hi / den_hi;
int64_t rem_sec = num_hi % den_hi;
if (rem_sec > 0) {
rem_sec -= den_hi;
quotient += 1;
}
if (num_lo != 0) {
rem_sec -= 1;
}
*q = quotient;
*rem = time_internal::MakeDuration(rem_sec, num_lo);
return true;
}
return false;
}
} // namespace
namespace time_internal {
// The 'satq' argument indicates whether the quotient should saturate at the
// bounds of int64_t. If it does saturate, the difference will spill over to
// the remainder. If it does not saturate, the remainder remain accurate,
// but the returned quotient will over/underflow int64_t and should not be used.
int64_t IDivDuration(bool satq, const Duration num, const Duration den,
Duration* rem) {
int64_t q = 0;
if (IDivFastPath(num, den, &q, rem)) {
return q;
}
const bool num_neg = num < ZeroDuration();
const bool den_neg = den < ZeroDuration();
const bool quotient_neg = num_neg != den_neg;
if (time_internal::IsInfiniteDuration(num) || den == ZeroDuration()) {
*rem = num_neg ? -InfiniteDuration() : InfiniteDuration();
return quotient_neg ? kint64min : kint64max;
}
if (time_internal::IsInfiniteDuration(den)) {
*rem = num;
return 0;
}
const uint128 a = MakeU128Ticks(num);
const uint128 b = MakeU128Ticks(den);
uint128 quotient128 = a / b;
if (satq) {
// Limits the quotient to the range of int64_t.
if (quotient128 > uint128(static_cast<uint64_t>(kint64max))) {
quotient128 = quotient_neg ? uint128(static_cast<uint64_t>(kint64min))
: uint128(static_cast<uint64_t>(kint64max));
}
}
const uint128 remainder128 = a - quotient128 * b;
*rem = MakeDurationFromU128(remainder128, num_neg);
if (!quotient_neg || quotient128 == 0) {
return Uint128Low64(quotient128) & kint64max;
}
// The quotient needs to be negated, but we need to carefully handle
// quotient128s with the top bit on.
return -static_cast<int64_t>(Uint128Low64(quotient128 - 1) & kint64max) - 1;
}
} // namespace time_internal
//
// Additive operators.
//
Duration& Duration::operator+=(Duration rhs) {
if (time_internal::IsInfiniteDuration(*this)) return *this;
if (time_internal::IsInfiniteDuration(rhs)) return *this = rhs;
const int64_t orig_rep_hi = rep_hi_;
rep_hi_ =
DecodeTwosComp(EncodeTwosComp(rep_hi_) + EncodeTwosComp(rhs.rep_hi_));
if (rep_lo_ >= kTicksPerSecond - rhs.rep_lo_) {
rep_hi_ = DecodeTwosComp(EncodeTwosComp(rep_hi_) + 1);
rep_lo_ -= kTicksPerSecond;
}
rep_lo_ += rhs.rep_lo_;
if (rhs.rep_hi_ < 0 ? rep_hi_ > orig_rep_hi : rep_hi_ < orig_rep_hi) {
return *this = rhs.rep_hi_ < 0 ? -InfiniteDuration() : InfiniteDuration();
}
return *this;
}
Duration& Duration::operator-=(Duration rhs) {
if (time_internal::IsInfiniteDuration(*this)) return *this;
if (time_internal::IsInfiniteDuration(rhs)) {
return *this = rhs.rep_hi_ >= 0 ? -InfiniteDuration() : InfiniteDuration();
}
const int64_t orig_rep_hi = rep_hi_;
rep_hi_ =
DecodeTwosComp(EncodeTwosComp(rep_hi_) - EncodeTwosComp(rhs.rep_hi_));
if (rep_lo_ < rhs.rep_lo_) {
rep_hi_ = DecodeTwosComp(EncodeTwosComp(rep_hi_) - 1);
rep_lo_ += kTicksPerSecond;
}
rep_lo_ -= rhs.rep_lo_;
if (rhs.rep_hi_ < 0 ? rep_hi_ < orig_rep_hi : rep_hi_ > orig_rep_hi) {
return *this = rhs.rep_hi_ >= 0 ? -InfiniteDuration() : InfiniteDuration();
}
return *this;
}
//
// Multiplicative operators.
//
Duration& Duration::operator*=(int64_t r) {
if (time_internal::IsInfiniteDuration(*this)) {
const bool is_neg = (r < 0) != (rep_hi_ < 0);
return *this = is_neg ? -InfiniteDuration() : InfiniteDuration();
}
return *this = ScaleFixed<SafeMultiply>(*this, r);
}
Duration& Duration::operator*=(double r) {
if (time_internal::IsInfiniteDuration(*this) || !IsFinite(r)) {
const bool is_neg = (std::signbit(r) != 0) != (rep_hi_ < 0);
return *this = is_neg ? -InfiniteDuration() : InfiniteDuration();
}
return *this = ScaleDouble<std::multiplies>(*this, r);
}
Duration& Duration::operator/=(int64_t r) {
if (time_internal::IsInfiniteDuration(*this) || r == 0) {
const bool is_neg = (r < 0) != (rep_hi_ < 0);
return *this = is_neg ? -InfiniteDuration() : InfiniteDuration();
}
return *this = ScaleFixed<std::divides>(*this, r);
}
Duration& Duration::operator/=(double r) {
if (time_internal::IsInfiniteDuration(*this) || r == 0.0) {
const bool is_neg = (std::signbit(r) != 0) != (rep_hi_ < 0);
return *this = is_neg ? -InfiniteDuration() : InfiniteDuration();
}
return *this = ScaleDouble<std::divides>(*this, r);
}
Duration& Duration::operator%=(Duration rhs) {
time_internal::IDivDuration(false, *this, rhs, this);
return *this;
}
double FDivDuration(Duration num, Duration den) {
// Arithmetic with infinity is sticky.
if (time_internal::IsInfiniteDuration(num) || den == ZeroDuration()) {
return (num < ZeroDuration()) == (den < ZeroDuration())
? std::numeric_limits<double>::infinity()
: -std::numeric_limits<double>::infinity();
}
if (time_internal::IsInfiniteDuration(den)) return 0.0;
double a =
static_cast<double>(time_internal::GetRepHi(num)) * kTicksPerSecond +
time_internal::GetRepLo(num);
double b =
static_cast<double>(time_internal::GetRepHi(den)) * kTicksPerSecond +
time_internal::GetRepLo(den);
return a / b;
}
//
// Trunc/Floor/Ceil.
//
Duration Trunc(Duration d, Duration unit) {
return d - (d % unit);
}
Duration Floor(const Duration d, const Duration unit) {
const absl::Duration td = Trunc(d, unit);
return td <= d ? td : td - AbsDuration(unit);
}
Duration Ceil(const Duration d, const Duration unit) {
const absl::Duration td = Trunc(d, unit);
return td >= d ? td : td + AbsDuration(unit);
}
//
// Factory functions.
//
Duration DurationFromTimespec(timespec ts) {
if (static_cast<uint64_t>(ts.tv_nsec) < 1000 * 1000 * 1000) {
int64_t ticks = ts.tv_nsec * kTicksPerNanosecond;
return time_internal::MakeDuration(ts.tv_sec, ticks);
}
return Seconds(ts.tv_sec) + Nanoseconds(ts.tv_nsec);
}
Duration DurationFromTimeval(timeval tv) {
if (static_cast<uint64_t>(tv.tv_usec) < 1000 * 1000) {
int64_t ticks = tv.tv_usec * 1000 * kTicksPerNanosecond;
return time_internal::MakeDuration(tv.tv_sec, ticks);
}
return Seconds(tv.tv_sec) + Microseconds(tv.tv_usec);
}
//
// Conversion to other duration types.
//
int64_t ToInt64Nanoseconds(Duration d) {
if (time_internal::GetRepHi(d) >= 0 &&
time_internal::GetRepHi(d) >> 33 == 0) {
return (time_internal::GetRepHi(d) * 1000 * 1000 * 1000) +
(time_internal::GetRepLo(d) / kTicksPerNanosecond);
}
return d / Nanoseconds(1);
}
int64_t ToInt64Microseconds(Duration d) {
if (time_internal::GetRepHi(d) >= 0 &&
time_internal::GetRepHi(d) >> 43 == 0) {
return (time_internal::GetRepHi(d) * 1000 * 1000) +
(time_internal::GetRepLo(d) / (kTicksPerNanosecond * 1000));
}
return d / Microseconds(1);
}
int64_t ToInt64Milliseconds(Duration d) {
if (time_internal::GetRepHi(d) >= 0 &&
time_internal::GetRepHi(d) >> 53 == 0) {
return (time_internal::GetRepHi(d) * 1000) +
(time_internal::GetRepLo(d) / (kTicksPerNanosecond * 1000 * 1000));
}
return d / Milliseconds(1);
}
int64_t ToInt64Seconds(Duration d) {
int64_t hi = time_internal::GetRepHi(d);
if (time_internal::IsInfiniteDuration(d)) return hi;
if (hi < 0 && time_internal::GetRepLo(d) != 0) ++hi;
return hi;
}
int64_t ToInt64Minutes(Duration d) {
int64_t hi = time_internal::GetRepHi(d);
if (time_internal::IsInfiniteDuration(d)) return hi;
if (hi < 0 && time_internal::GetRepLo(d) != 0) ++hi;
return hi / 60;
}
int64_t ToInt64Hours(Duration d) {
int64_t hi = time_internal::GetRepHi(d);
if (time_internal::IsInfiniteDuration(d)) return hi;
if (hi < 0 && time_internal::GetRepLo(d) != 0) ++hi;
return hi / (60 * 60);
}
double ToDoubleNanoseconds(Duration d) {
return FDivDuration(d, Nanoseconds(1));
}
double ToDoubleMicroseconds(Duration d) {
return FDivDuration(d, Microseconds(1));
}
double ToDoubleMilliseconds(Duration d) {
return FDivDuration(d, Milliseconds(1));
}
double ToDoubleSeconds(Duration d) {
return FDivDuration(d, Seconds(1));
}
double ToDoubleMinutes(Duration d) {
return FDivDuration(d, Minutes(1));
}
double ToDoubleHours(Duration d) {
return FDivDuration(d, Hours(1));
}
timespec ToTimespec(Duration d) {
timespec ts;
if (!time_internal::IsInfiniteDuration(d)) {
int64_t rep_hi = time_internal::GetRepHi(d);
uint32_t rep_lo = time_internal::GetRepLo(d);
if (rep_hi < 0) {
// Tweak the fields so that unsigned division of rep_lo
// maps to truncation (towards zero) for the timespec.
rep_lo += kTicksPerNanosecond - 1;
if (rep_lo >= kTicksPerSecond) {
rep_hi += 1;
rep_lo -= kTicksPerSecond;
}
}
ts.tv_sec = rep_hi;
if (ts.tv_sec == rep_hi) { // no time_t narrowing
ts.tv_nsec = rep_lo / kTicksPerNanosecond;
return ts;
}
}
if (d >= ZeroDuration()) {
ts.tv_sec = std::numeric_limits<time_t>::max();
ts.tv_nsec = 1000 * 1000 * 1000 - 1;
} else {
ts.tv_sec = std::numeric_limits<time_t>::min();
ts.tv_nsec = 0;
}
return ts;
}
timeval ToTimeval(Duration d) {
timeval tv;
timespec ts = ToTimespec(d);
if (ts.tv_sec < 0) {
// Tweak the fields so that positive division of tv_nsec
// maps to truncation (towards zero) for the timeval.
ts.tv_nsec += 1000 - 1;
if (ts.tv_nsec >= 1000 * 1000 * 1000) {
ts.tv_sec += 1;
ts.tv_nsec -= 1000 * 1000 * 1000;
}
}
tv.tv_sec = ts.tv_sec;
if (tv.tv_sec != ts.tv_sec) { // narrowing
if (ts.tv_sec < 0) {
tv.tv_sec = std::numeric_limits<decltype(tv.tv_sec)>::min();
tv.tv_usec = 0;
} else {
tv.tv_sec = std::numeric_limits<decltype(tv.tv_sec)>::max();
tv.tv_usec = 1000 * 1000 - 1;
}
return tv;
}
tv.tv_usec = static_cast<int>(ts.tv_nsec / 1000); // suseconds_t
return tv;
}
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
2017-09-24 17:20:48 +02:00
std::chrono::nanoseconds ToChronoNanoseconds(Duration d) {
return time_internal::ToChronoDuration<std::chrono::nanoseconds>(d);
}
std::chrono::microseconds ToChronoMicroseconds(Duration d) {
return time_internal::ToChronoDuration<std::chrono::microseconds>(d);
}
std::chrono::milliseconds ToChronoMilliseconds(Duration d) {
return time_internal::ToChronoDuration<std::chrono::milliseconds>(d);
}
std::chrono::seconds ToChronoSeconds(Duration d) {
return time_internal::ToChronoDuration<std::chrono::seconds>(d);
}
std::chrono::minutes ToChronoMinutes(Duration d) {
return time_internal::ToChronoDuration<std::chrono::minutes>(d);
}
std::chrono::hours ToChronoHours(Duration d) {
return time_internal::ToChronoDuration<std::chrono::hours>(d);
}
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//
// To/From std::string formatting.
//
namespace {
// Formats a positive 64-bit integer in the given field width. Note that
// it is up to the caller of Format64() to ensure that there is sufficient
// space before ep to hold the conversion.
char* Format64(char* ep, int width, int64_t v) {
do {
--width;
*--ep = '0' + (v % 10); // contiguous digits
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} while (v /= 10);
while (--width >= 0) *--ep = '0'; // zero pad
return ep;
}
// Helpers for FormatDuration() that format 'n' and append it to 'out'
// followed by the given 'unit'. If 'n' formats to "0", nothing is
// appended (not even the unit).
// A type that encapsulates how to display a value of a particular unit. For
// values that are displayed with fractional parts, the precision indicates
// where to round the value. The precision varies with the display unit because
// a Duration can hold only quarters of a nanosecond, so displaying information
// beyond that is just noise.
//
// For example, a microsecond value of 42.00025xxxxx should not display beyond 5
// fractional digits, because it is in the noise of what a Duration can
// represent.
struct DisplayUnit {
const char* abbr;
int prec;
double pow10;
};
const DisplayUnit kDisplayNano = {"ns", 2, 1e2};
const DisplayUnit kDisplayMicro = {"us", 5, 1e5};
const DisplayUnit kDisplayMilli = {"ms", 8, 1e8};
const DisplayUnit kDisplaySec = {"s", 11, 1e11};
const DisplayUnit kDisplayMin = {"m", -1, 0.0}; // prec ignored
const DisplayUnit kDisplayHour = {"h", -1, 0.0}; // prec ignored
void AppendNumberUnit(std::string* out, int64_t n, DisplayUnit unit) {
char buf[sizeof("2562047788015216")]; // hours in max duration
char* const ep = buf + sizeof(buf);
char* bp = Format64(ep, 0, n);
if (*bp != '0' || bp + 1 != ep) {
out->append(bp, ep - bp);
out->append(unit.abbr);
}
}
// Note: unit.prec is limited to double's digits10 value (typically 15) so it
// always fits in buf[].
void AppendNumberUnit(std::string* out, double n, DisplayUnit unit) {
const int buf_size = std::numeric_limits<double>::digits10;
const int prec = std::min(buf_size, unit.prec);
char buf[buf_size]; // also large enough to hold integer part
char* ep = buf + sizeof(buf);
double d = 0;
int64_t frac_part = Round(std::modf(n, &d) * unit.pow10);
int64_t int_part = d;
if (int_part != 0 || frac_part != 0) {
char* bp = Format64(ep, 0, int_part); // always < 1000
out->append(bp, ep - bp);
if (frac_part != 0) {
out->push_back('.');
bp = Format64(ep, prec, frac_part);
while (ep[-1] == '0') --ep;
out->append(bp, ep - bp);
}
out->append(unit.abbr);
}
}
} // namespace
// From Go's doc at http://golang.org/pkg/time/#Duration.String
// [FormatDuration] returns a std::string representing the duration in the
// form "72h3m0.5s". Leading zero units are omitted. As a special
// case, durations less than one second format use a smaller unit
// (milli-, micro-, or nanoseconds) to ensure that the leading digit
// is non-zero. The zero duration formats as 0, with no unit.
std::string FormatDuration(Duration d) {
const Duration min_duration = Seconds(kint64min);
if (d == min_duration) {
// Avoid needing to negate kint64min by directly returning what the
// following code should produce in that case.
return "-2562047788015215h30m8s";
}
std::string s;
if (d < ZeroDuration()) {
s.append("-");
d = -d;
}
if (d == InfiniteDuration()) {
s.append("inf");
} else if (d < Seconds(1)) {
// Special case for durations with a magnitude < 1 second. The duration
// is printed as a fraction of a single unit, e.g., "1.2ms".
if (d < Microseconds(1)) {
AppendNumberUnit(&s, FDivDuration(d, Nanoseconds(1)), kDisplayNano);
} else if (d < Milliseconds(1)) {
AppendNumberUnit(&s, FDivDuration(d, Microseconds(1)), kDisplayMicro);
} else {
AppendNumberUnit(&s, FDivDuration(d, Milliseconds(1)), kDisplayMilli);
}
} else {
AppendNumberUnit(&s, IDivDuration(d, Hours(1), &d), kDisplayHour);
AppendNumberUnit(&s, IDivDuration(d, Minutes(1), &d), kDisplayMin);
AppendNumberUnit(&s, FDivDuration(d, Seconds(1)), kDisplaySec);
}
if (s.empty() || s == "-") {
s = "0";
}
return s;
}
namespace {
// A helper for ParseDuration() that parses a leading number from the given
// std::string and stores the result in *int_part/*frac_part/*frac_scale. The
// given std::string pointer is modified to point to the first unconsumed char.
bool ConsumeDurationNumber(const char** dpp, int64_t* int_part,
int64_t* frac_part, int64_t* frac_scale) {
*int_part = 0;
*frac_part = 0;
*frac_scale = 1; // invariant: *frac_part < *frac_scale
const char* start = *dpp;
for (; std::isdigit(**dpp); *dpp += 1) {
const int d = **dpp - '0'; // contiguous digits
if (*int_part > kint64max / 10) return false;
*int_part *= 10;
if (*int_part > kint64max - d) return false;
*int_part += d;
}
const bool int_part_empty = (*dpp == start);
if (**dpp != '.') return !int_part_empty;
for (*dpp += 1; std::isdigit(**dpp); *dpp += 1) {
const int d = **dpp - '0'; // contiguous digits
if (*frac_scale <= kint64max / 10) {
*frac_part *= 10;
*frac_part += d;
*frac_scale *= 10;
}
}
return !int_part_empty || *frac_scale != 1;
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}
// A helper for ParseDuration() that parses a leading unit designator (e.g.,
// ns, us, ms, s, m, h) from the given std::string and stores the resulting unit
// in "*unit". The given std::string pointer is modified to point to the first
// unconsumed char.
bool ConsumeDurationUnit(const char** start, Duration* unit) {
const char *s = *start;
bool ok = true;
if (strncmp(s, "ns", 2) == 0) {
s += 2;
*unit = Nanoseconds(1);
} else if (strncmp(s, "us", 2) == 0) {
s += 2;
*unit = Microseconds(1);
} else if (strncmp(s, "ms", 2) == 0) {
s += 2;
*unit = Milliseconds(1);
} else if (strncmp(s, "s", 1) == 0) {
s += 1;
*unit = Seconds(1);
} else if (strncmp(s, "m", 1) == 0) {
s += 1;
*unit = Minutes(1);
} else if (strncmp(s, "h", 1) == 0) {
s += 1;
*unit = Hours(1);
} else {
ok = false;
}
*start = s;
return ok;
}
} // namespace
// From Go's doc at http://golang.org/pkg/time/#ParseDuration
// [ParseDuration] parses a duration std::string. A duration std::string is
// a possibly signed sequence of decimal numbers, each with optional
// fraction and a unit suffix, such as "300ms", "-1.5h" or "2h45m".
// Valid time units are "ns", "us" "ms", "s", "m", "h".
bool ParseDuration(const std::string& dur_string, Duration* d) {
const char* start = dur_string.c_str();
int sign = 1;
if (*start == '-' || *start == '+') {
sign = *start == '-' ? -1 : 1;
++start;
}
// Can't parse a duration from an empty std::string.
if (*start == '\0') {
return false;
}
// Special case for a std::string of "0".
if (*start == '0' && *(start + 1) == '\0') {
*d = ZeroDuration();
return true;
}
if (strcmp(start, "inf") == 0) {
*d = sign * InfiniteDuration();
return true;
}
Duration dur;
while (*start != '\0') {
int64_t int_part;
int64_t frac_part;
int64_t frac_scale;
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Duration unit;
if (!ConsumeDurationNumber(&start, &int_part, &frac_part, &frac_scale) ||
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!ConsumeDurationUnit(&start, &unit)) {
return false;
}
if (int_part != 0) dur += sign * int_part * unit;
if (frac_part != 0) dur += sign * frac_part * unit / frac_scale;
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}
*d = dur;
return true;
}
-- f28d30df5769bb832dec3ff36d2fcd2bcdf494a3 by Shaindel Schwartz <shaindel@google.com>: Internal change PiperOrigin-RevId: 201046831 -- 711715a78b7e53dfaafd4d7f08a74e76db22af88 by Mark Barolak <mbar@google.com>: Internal fix PiperOrigin-RevId: 201043684 -- 64b53edd6bf1fa48f74e7f5d33f00f80d5089147 by Shaindel Schwartz <shaindel@google.com>: Remove extra whitespace PiperOrigin-RevId: 201041989 -- 0bdd2a0b33657b688e4a04aeba9ebba47e4dc6ca by Shaindel Schwartz <shaindel@google.com>: Whitespace fix. PiperOrigin-RevId: 201034413 -- 3deb0ac296ef1b74c4789e114a8a8bf53253f26b by Shaindel Schwartz <shaindel@google.com>: Scrub build tags. No functional changes. PiperOrigin-RevId: 201032927 -- da75d0f8b73baa7e8f4e9a092bba546012ed3b71 by Alex Strelnikov <strel@google.com>: Internal change. PiperOrigin-RevId: 201026131 -- 6815d80caa19870d0c441b6b9816c68db41393a5 by Tom Manshreck <shreck@google.com>: Add documentation for our LTS snapshot branches PiperOrigin-RevId: 201025191 -- 64c3b02006f39e6a8127bbabf9ec947fb45b6504 by Greg Falcon <gfalcon@google.com>: Provide absl::from_chars for double and float types. This is a forward-compatible implementation of std::from_chars from C++17. This provides exact "round_to_nearest" conversions, and has some nice properties: * Works with string_view (it can convert numbers from non-NUL-terminated buffers) * Never allocates memory * Faster than the standard library strtod() in our toolchain * Uses integer math in its calculations, so is unaffected by floating point environment * Unaffected by C locale Also change SimpleAtod/SimpleAtoi to use this new API under the hood. PiperOrigin-RevId: 201003324 -- 542869258eb100779497c899103dc96aced52749 by Greg Falcon <gfalcon@google.com>: Internal change PiperOrigin-RevId: 200999200 -- 3aba192775c7f80e2cd7f221b0a73537823c54ea by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 200947470 -- daf9b9feedd748d5364a4c06165b7cb7604d3e1e by Mark Barolak <mbar@google.com>: Add an absl:: qualification to a usage of base_internal::SchedulingMode outside of an absl:: namespace. PiperOrigin-RevId: 200748234 -- a8d265290a22d629f3d9bf9f872c204200bfe8c8 by Mark Barolak <mbar@google.com>: Add a missing namespace closing comment to optional.h. PiperOrigin-RevId: 200739934 -- f05af8ee1c6b864dad2df7c907d424209a3e3202 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 200719115 GitOrigin-RevId: f28d30df5769bb832dec3ff36d2fcd2bcdf494a3 Change-Id: Ie4fa601078fd4aa57286372611f1d114fdec82c0
2018-06-18 22:18:53 +02:00
bool ParseFlag(const std::string& text, Duration* dst, std::string* ) {
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return ParseDuration(text, dst);
}
Export of internal Abseil changes. -- ac7508120c60dfe689c40929e416b6a486f83ee3 by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 206912089 -- bd709faba88565367b6d337466e6456481b5f3e8 by Matt Calabrese <calabrese@google.com>: Implement `std::experimental::is_detected` in type_traits internals and move `is_detected_convertible` from variant's internals to type_traits internals. This is in preparation of creating workarounds for broken standard traits. PiperOrigin-RevId: 206825598 -- 0dbddea569370eb9b6348cee172d1874f9046eb4 by Jorg Brown <jorg@google.com>: Support users who turn on floating-point conversion warnings PiperOrigin-RevId: 206813209 -- 30991f757c8f0100584619d8a9c41897d029f112 by Jorg Brown <jorg@google.com>: Speed up the absl::Seconds() function for floating-point values, roughly by 4.5x, since we can take advantage of the fact that we're just taking a floating-point number and splitting it into its integral and fractional parts. PiperOrigin-RevId: 206806270 -- 6883837176838aa5a517e7a8cb4c99afd24c0d12 by Jon Cohen <cohenjon@google.com>: Remove the DISABLE_INSTALL from absl_container. It doesn't do anything. PiperOrigin-RevId: 206802544 -- 92ab14fed06e6dd1f01a0284bd7f95d3e2c0c3d8 by Jon Cohen <cohenjon@google.com>: Internal change PiperOrigin-RevId: 206776244 -- 17b76c7f364ac562d9e0faeca0320f63aa3fdb85 by Jorg Brown <jorg@google.com>: Fix absl/strings:numbers_test flakiness due to exceeding the 1-minute timeout PiperOrigin-RevId: 206763175 -- 6637843f2e198b8efd90e5577fbc86bdea43b2cc by Abseil Team <absl-team@google.com>: Adds templated allocator to absl::FixedArray with corresponding tests PiperOrigin-RevId: 206354178 -- bced22f81add828c9b4c60eb45554d36c22e2f96 by Abseil Team <absl-team@google.com>: Adds templated allocator to absl::FixedArray with corresponding tests PiperOrigin-RevId: 206347377 -- 75be14a71d2d5e335812d5b7670120271fb5bd79 by Abseil Team <absl-team@google.com>: Internal change. PiperOrigin-RevId: 206326935 -- 6929e43f4c7898b1f51e441911a19092a06fbf97 by Abseil Team <absl-team@google.com>: Adds templated allocator to absl::FixedArray with corresponding tests PiperOrigin-RevId: 206326368 -- 55ae34b75ff029eb267f9519e577bab8a575b487 by Abseil Team <absl-team@google.com>: Internal change. PiperOrigin-RevId: 206233448 -- 6950a8ccddf35d451eec2d02cd28a797c8b7cf6a by Matt Kulukundis <kfm@google.com>: Internal change PiperOrigin-RevId: 206035613 GitOrigin-RevId: ac7508120c60dfe689c40929e416b6a486f83ee3 Change-Id: I675605abbedab6b3ac9aa82195cbd059ff7c82b1
2018-08-01 13:34:12 +02:00
std::string UnparseFlag(Duration d) { return FormatDuration(d); }
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} // namespace absl