xref: /aosp_15_r20/external/abseil-cpp/absl/time/duration.cc (revision 9356374a3709195abf420251b3e825997ff56c0f)
1*9356374aSAndroid Build Coastguard Worker // Copyright 2017 The Abseil Authors.
2*9356374aSAndroid Build Coastguard Worker //
3*9356374aSAndroid Build Coastguard Worker // Licensed under the Apache License, Version 2.0 (the "License");
4*9356374aSAndroid Build Coastguard Worker // you may not use this file except in compliance with the License.
5*9356374aSAndroid Build Coastguard Worker // You may obtain a copy of the License at
6*9356374aSAndroid Build Coastguard Worker //
7*9356374aSAndroid Build Coastguard Worker //      https://www.apache.org/licenses/LICENSE-2.0
8*9356374aSAndroid Build Coastguard Worker //
9*9356374aSAndroid Build Coastguard Worker // Unless required by applicable law or agreed to in writing, software
10*9356374aSAndroid Build Coastguard Worker // distributed under the License is distributed on an "AS IS" BASIS,
11*9356374aSAndroid Build Coastguard Worker // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12*9356374aSAndroid Build Coastguard Worker // See the License for the specific language governing permissions and
13*9356374aSAndroid Build Coastguard Worker // limitations under the License.
14*9356374aSAndroid Build Coastguard Worker 
15*9356374aSAndroid Build Coastguard Worker // The implementation of the absl::Duration class, which is declared in
16*9356374aSAndroid Build Coastguard Worker // //absl/time.h.  This class behaves like a numeric type; it has no public
17*9356374aSAndroid Build Coastguard Worker // methods and is used only through the operators defined here.
18*9356374aSAndroid Build Coastguard Worker //
19*9356374aSAndroid Build Coastguard Worker // Implementation notes:
20*9356374aSAndroid Build Coastguard Worker //
21*9356374aSAndroid Build Coastguard Worker // An absl::Duration is represented as
22*9356374aSAndroid Build Coastguard Worker //
23*9356374aSAndroid Build Coastguard Worker //   rep_hi_ : (int64_t)  Whole seconds
24*9356374aSAndroid Build Coastguard Worker //   rep_lo_ : (uint32_t) Fractions of a second
25*9356374aSAndroid Build Coastguard Worker //
26*9356374aSAndroid Build Coastguard Worker // The seconds value (rep_hi_) may be positive or negative as appropriate.
27*9356374aSAndroid Build Coastguard Worker // The fractional seconds (rep_lo_) is always a positive offset from rep_hi_.
28*9356374aSAndroid Build Coastguard Worker // The API for Duration guarantees at least nanosecond resolution, which
29*9356374aSAndroid Build Coastguard Worker // means rep_lo_ could have a max value of 1B - 1 if it stored nanoseconds.
30*9356374aSAndroid Build Coastguard Worker // However, to utilize more of the available 32 bits of space in rep_lo_,
31*9356374aSAndroid Build Coastguard Worker // we instead store quarters of a nanosecond in rep_lo_ resulting in a max
32*9356374aSAndroid Build Coastguard Worker // value of 4B - 1.  This allows us to correctly handle calculations like
33*9356374aSAndroid Build Coastguard Worker // 0.5 nanos + 0.5 nanos = 1 nano.  The following example shows the actual
34*9356374aSAndroid Build Coastguard Worker // Duration rep using quarters of a nanosecond.
35*9356374aSAndroid Build Coastguard Worker //
36*9356374aSAndroid Build Coastguard Worker //    2.5 sec = {rep_hi_=2,  rep_lo_=2000000000}  // lo = 4 * 500000000
37*9356374aSAndroid Build Coastguard Worker //   -2.5 sec = {rep_hi_=-3, rep_lo_=2000000000}
38*9356374aSAndroid Build Coastguard Worker //
39*9356374aSAndroid Build Coastguard Worker // Infinite durations are represented as Durations with the rep_lo_ field set
40*9356374aSAndroid Build Coastguard Worker // to all 1s.
41*9356374aSAndroid Build Coastguard Worker //
42*9356374aSAndroid Build Coastguard Worker //   +InfiniteDuration:
43*9356374aSAndroid Build Coastguard Worker //     rep_hi_ : kint64max
44*9356374aSAndroid Build Coastguard Worker //     rep_lo_ : ~0U
45*9356374aSAndroid Build Coastguard Worker //
46*9356374aSAndroid Build Coastguard Worker //   -InfiniteDuration:
47*9356374aSAndroid Build Coastguard Worker //     rep_hi_ : kint64min
48*9356374aSAndroid Build Coastguard Worker //     rep_lo_ : ~0U
49*9356374aSAndroid Build Coastguard Worker //
50*9356374aSAndroid Build Coastguard Worker // Arithmetic overflows/underflows to +/- infinity and saturates.
51*9356374aSAndroid Build Coastguard Worker 
52*9356374aSAndroid Build Coastguard Worker #if defined(_MSC_VER)
53*9356374aSAndroid Build Coastguard Worker #include <winsock2.h>  // for timeval
54*9356374aSAndroid Build Coastguard Worker #endif
55*9356374aSAndroid Build Coastguard Worker 
56*9356374aSAndroid Build Coastguard Worker #include <algorithm>
57*9356374aSAndroid Build Coastguard Worker #include <cassert>
58*9356374aSAndroid Build Coastguard Worker #include <chrono>  // NOLINT(build/c++11)
59*9356374aSAndroid Build Coastguard Worker #include <cmath>
60*9356374aSAndroid Build Coastguard Worker #include <cstdint>
61*9356374aSAndroid Build Coastguard Worker #include <cstdlib>
62*9356374aSAndroid Build Coastguard Worker #include <cstring>
63*9356374aSAndroid Build Coastguard Worker #include <ctime>
64*9356374aSAndroid Build Coastguard Worker #include <functional>
65*9356374aSAndroid Build Coastguard Worker #include <limits>
66*9356374aSAndroid Build Coastguard Worker #include <string>
67*9356374aSAndroid Build Coastguard Worker 
68*9356374aSAndroid Build Coastguard Worker #include "absl/base/attributes.h"
69*9356374aSAndroid Build Coastguard Worker #include "absl/base/casts.h"
70*9356374aSAndroid Build Coastguard Worker #include "absl/base/config.h"
71*9356374aSAndroid Build Coastguard Worker #include "absl/numeric/int128.h"
72*9356374aSAndroid Build Coastguard Worker #include "absl/strings/string_view.h"
73*9356374aSAndroid Build Coastguard Worker #include "absl/strings/strip.h"
74*9356374aSAndroid Build Coastguard Worker #include "absl/time/time.h"
75*9356374aSAndroid Build Coastguard Worker 
76*9356374aSAndroid Build Coastguard Worker namespace absl {
77*9356374aSAndroid Build Coastguard Worker ABSL_NAMESPACE_BEGIN
78*9356374aSAndroid Build Coastguard Worker 
79*9356374aSAndroid Build Coastguard Worker namespace {
80*9356374aSAndroid Build Coastguard Worker 
81*9356374aSAndroid Build Coastguard Worker using time_internal::kTicksPerNanosecond;
82*9356374aSAndroid Build Coastguard Worker using time_internal::kTicksPerSecond;
83*9356374aSAndroid Build Coastguard Worker 
84*9356374aSAndroid Build Coastguard Worker constexpr int64_t kint64max = std::numeric_limits<int64_t>::max();
85*9356374aSAndroid Build Coastguard Worker constexpr int64_t kint64min = std::numeric_limits<int64_t>::min();
86*9356374aSAndroid Build Coastguard Worker 
87*9356374aSAndroid Build Coastguard Worker // Can't use std::isinfinite() because it doesn't exist on windows.
IsFinite(double d)88*9356374aSAndroid Build Coastguard Worker inline bool IsFinite(double d) {
89*9356374aSAndroid Build Coastguard Worker   if (std::isnan(d)) return false;
90*9356374aSAndroid Build Coastguard Worker   return d != std::numeric_limits<double>::infinity() &&
91*9356374aSAndroid Build Coastguard Worker          d != -std::numeric_limits<double>::infinity();
92*9356374aSAndroid Build Coastguard Worker }
93*9356374aSAndroid Build Coastguard Worker 
IsValidDivisor(double d)94*9356374aSAndroid Build Coastguard Worker inline bool IsValidDivisor(double d) {
95*9356374aSAndroid Build Coastguard Worker   if (std::isnan(d)) return false;
96*9356374aSAndroid Build Coastguard Worker   return d != 0.0;
97*9356374aSAndroid Build Coastguard Worker }
98*9356374aSAndroid Build Coastguard Worker 
99*9356374aSAndroid Build Coastguard Worker // *sec may be positive or negative.  *ticks must be in the range
100*9356374aSAndroid Build Coastguard Worker // -kTicksPerSecond < *ticks < kTicksPerSecond.  If *ticks is negative it
101*9356374aSAndroid Build Coastguard Worker // will be normalized to a positive value by adjusting *sec accordingly.
NormalizeTicks(int64_t * sec,int64_t * ticks)102*9356374aSAndroid Build Coastguard Worker inline void NormalizeTicks(int64_t* sec, int64_t* ticks) {
103*9356374aSAndroid Build Coastguard Worker   if (*ticks < 0) {
104*9356374aSAndroid Build Coastguard Worker     --*sec;
105*9356374aSAndroid Build Coastguard Worker     *ticks += kTicksPerSecond;
106*9356374aSAndroid Build Coastguard Worker   }
107*9356374aSAndroid Build Coastguard Worker }
108*9356374aSAndroid Build Coastguard Worker 
109*9356374aSAndroid Build Coastguard Worker // Makes a uint128 from the absolute value of the given scalar.
MakeU128(int64_t a)110*9356374aSAndroid Build Coastguard Worker inline uint128 MakeU128(int64_t a) {
111*9356374aSAndroid Build Coastguard Worker   uint128 u128 = 0;
112*9356374aSAndroid Build Coastguard Worker   if (a < 0) {
113*9356374aSAndroid Build Coastguard Worker     ++u128;
114*9356374aSAndroid Build Coastguard Worker     ++a;  // Makes it safe to negate 'a'
115*9356374aSAndroid Build Coastguard Worker     a = -a;
116*9356374aSAndroid Build Coastguard Worker   }
117*9356374aSAndroid Build Coastguard Worker   u128 += static_cast<uint64_t>(a);
118*9356374aSAndroid Build Coastguard Worker   return u128;
119*9356374aSAndroid Build Coastguard Worker }
120*9356374aSAndroid Build Coastguard Worker 
121*9356374aSAndroid Build Coastguard Worker // Makes a uint128 count of ticks out of the absolute value of the Duration.
MakeU128Ticks(Duration d)122*9356374aSAndroid Build Coastguard Worker inline uint128 MakeU128Ticks(Duration d) {
123*9356374aSAndroid Build Coastguard Worker   int64_t rep_hi = time_internal::GetRepHi(d);
124*9356374aSAndroid Build Coastguard Worker   uint32_t rep_lo = time_internal::GetRepLo(d);
125*9356374aSAndroid Build Coastguard Worker   if (rep_hi < 0) {
126*9356374aSAndroid Build Coastguard Worker     ++rep_hi;
127*9356374aSAndroid Build Coastguard Worker     rep_hi = -rep_hi;
128*9356374aSAndroid Build Coastguard Worker     rep_lo = kTicksPerSecond - rep_lo;
129*9356374aSAndroid Build Coastguard Worker   }
130*9356374aSAndroid Build Coastguard Worker   uint128 u128 = static_cast<uint64_t>(rep_hi);
131*9356374aSAndroid Build Coastguard Worker   u128 *= static_cast<uint64_t>(kTicksPerSecond);
132*9356374aSAndroid Build Coastguard Worker   u128 += rep_lo;
133*9356374aSAndroid Build Coastguard Worker   return u128;
134*9356374aSAndroid Build Coastguard Worker }
135*9356374aSAndroid Build Coastguard Worker 
136*9356374aSAndroid Build Coastguard Worker // Breaks a uint128 of ticks into a Duration.
MakeDurationFromU128(uint128 u128,bool is_neg)137*9356374aSAndroid Build Coastguard Worker inline Duration MakeDurationFromU128(uint128 u128, bool is_neg) {
138*9356374aSAndroid Build Coastguard Worker   int64_t rep_hi;
139*9356374aSAndroid Build Coastguard Worker   uint32_t rep_lo;
140*9356374aSAndroid Build Coastguard Worker   const uint64_t h64 = Uint128High64(u128);
141*9356374aSAndroid Build Coastguard Worker   const uint64_t l64 = Uint128Low64(u128);
142*9356374aSAndroid Build Coastguard Worker   if (h64 == 0) {  // fastpath
143*9356374aSAndroid Build Coastguard Worker     const uint64_t hi = l64 / kTicksPerSecond;
144*9356374aSAndroid Build Coastguard Worker     rep_hi = static_cast<int64_t>(hi);
145*9356374aSAndroid Build Coastguard Worker     rep_lo = static_cast<uint32_t>(l64 - hi * kTicksPerSecond);
146*9356374aSAndroid Build Coastguard Worker   } else {
147*9356374aSAndroid Build Coastguard Worker     // kMaxRepHi64 is the high 64 bits of (2^63 * kTicksPerSecond).
148*9356374aSAndroid Build Coastguard Worker     // Any positive tick count whose high 64 bits are >= kMaxRepHi64
149*9356374aSAndroid Build Coastguard Worker     // is not representable as a Duration.  A negative tick count can
150*9356374aSAndroid Build Coastguard Worker     // have its high 64 bits == kMaxRepHi64 but only when the low 64
151*9356374aSAndroid Build Coastguard Worker     // bits are all zero, otherwise it is not representable either.
152*9356374aSAndroid Build Coastguard Worker     const uint64_t kMaxRepHi64 = 0x77359400UL;
153*9356374aSAndroid Build Coastguard Worker     if (h64 >= kMaxRepHi64) {
154*9356374aSAndroid Build Coastguard Worker       if (is_neg && h64 == kMaxRepHi64 && l64 == 0) {
155*9356374aSAndroid Build Coastguard Worker         // Avoid trying to represent -kint64min below.
156*9356374aSAndroid Build Coastguard Worker         return time_internal::MakeDuration(kint64min);
157*9356374aSAndroid Build Coastguard Worker       }
158*9356374aSAndroid Build Coastguard Worker       return is_neg ? -InfiniteDuration() : InfiniteDuration();
159*9356374aSAndroid Build Coastguard Worker     }
160*9356374aSAndroid Build Coastguard Worker     const uint128 kTicksPerSecond128 = static_cast<uint64_t>(kTicksPerSecond);
161*9356374aSAndroid Build Coastguard Worker     const uint128 hi = u128 / kTicksPerSecond128;
162*9356374aSAndroid Build Coastguard Worker     rep_hi = static_cast<int64_t>(Uint128Low64(hi));
163*9356374aSAndroid Build Coastguard Worker     rep_lo =
164*9356374aSAndroid Build Coastguard Worker         static_cast<uint32_t>(Uint128Low64(u128 - hi * kTicksPerSecond128));
165*9356374aSAndroid Build Coastguard Worker   }
166*9356374aSAndroid Build Coastguard Worker   if (is_neg) {
167*9356374aSAndroid Build Coastguard Worker     rep_hi = -rep_hi;
168*9356374aSAndroid Build Coastguard Worker     if (rep_lo != 0) {
169*9356374aSAndroid Build Coastguard Worker       --rep_hi;
170*9356374aSAndroid Build Coastguard Worker       rep_lo = kTicksPerSecond - rep_lo;
171*9356374aSAndroid Build Coastguard Worker     }
172*9356374aSAndroid Build Coastguard Worker   }
173*9356374aSAndroid Build Coastguard Worker   return time_internal::MakeDuration(rep_hi, rep_lo);
174*9356374aSAndroid Build Coastguard Worker }
175*9356374aSAndroid Build Coastguard Worker 
176*9356374aSAndroid Build Coastguard Worker // Convert between int64_t and uint64_t, preserving representation. This
177*9356374aSAndroid Build Coastguard Worker // allows us to do arithmetic in the unsigned domain, where overflow has
178*9356374aSAndroid Build Coastguard Worker // well-defined behavior. See operator+=() and operator-=().
179*9356374aSAndroid Build Coastguard Worker //
180*9356374aSAndroid Build Coastguard Worker // C99 7.20.1.1.1, as referenced by C++11 18.4.1.2, says, "The typedef
181*9356374aSAndroid Build Coastguard Worker // name intN_t designates a signed integer type with width N, no padding
182*9356374aSAndroid Build Coastguard Worker // bits, and a two's complement representation." So, we can convert to
183*9356374aSAndroid Build Coastguard Worker // and from the corresponding uint64_t value using a bit cast.
EncodeTwosComp(int64_t v)184*9356374aSAndroid Build Coastguard Worker inline uint64_t EncodeTwosComp(int64_t v) {
185*9356374aSAndroid Build Coastguard Worker   return absl::bit_cast<uint64_t>(v);
186*9356374aSAndroid Build Coastguard Worker }
DecodeTwosComp(uint64_t v)187*9356374aSAndroid Build Coastguard Worker inline int64_t DecodeTwosComp(uint64_t v) { return absl::bit_cast<int64_t>(v); }
188*9356374aSAndroid Build Coastguard Worker 
189*9356374aSAndroid Build Coastguard Worker // Note: The overflow detection in this function is done using greater/less *or
190*9356374aSAndroid Build Coastguard Worker // equal* because kint64max/min is too large to be represented exactly in a
191*9356374aSAndroid Build Coastguard Worker // double (which only has 53 bits of precision). In order to avoid assigning to
192*9356374aSAndroid Build Coastguard Worker // rep->hi a double value that is too large for an int64_t (and therefore is
193*9356374aSAndroid Build Coastguard Worker // undefined), we must consider computations that equal kint64max/min as a
194*9356374aSAndroid Build Coastguard Worker // double as overflow cases.
SafeAddRepHi(double a_hi,double b_hi,Duration * d)195*9356374aSAndroid Build Coastguard Worker inline bool SafeAddRepHi(double a_hi, double b_hi, Duration* d) {
196*9356374aSAndroid Build Coastguard Worker   double c = a_hi + b_hi;
197*9356374aSAndroid Build Coastguard Worker   if (c >= static_cast<double>(kint64max)) {
198*9356374aSAndroid Build Coastguard Worker     *d = InfiniteDuration();
199*9356374aSAndroid Build Coastguard Worker     return false;
200*9356374aSAndroid Build Coastguard Worker   }
201*9356374aSAndroid Build Coastguard Worker   if (c <= static_cast<double>(kint64min)) {
202*9356374aSAndroid Build Coastguard Worker     *d = -InfiniteDuration();
203*9356374aSAndroid Build Coastguard Worker     return false;
204*9356374aSAndroid Build Coastguard Worker   }
205*9356374aSAndroid Build Coastguard Worker   *d = time_internal::MakeDuration(c, time_internal::GetRepLo(*d));
206*9356374aSAndroid Build Coastguard Worker   return true;
207*9356374aSAndroid Build Coastguard Worker }
208*9356374aSAndroid Build Coastguard Worker 
209*9356374aSAndroid Build Coastguard Worker // A functor that's similar to std::multiplies<T>, except this returns the max
210*9356374aSAndroid Build Coastguard Worker // T value instead of overflowing. This is only defined for uint128.
211*9356374aSAndroid Build Coastguard Worker template <typename Ignored>
212*9356374aSAndroid Build Coastguard Worker struct SafeMultiply {
operator ()absl::__anon7f68cfbf0111::SafeMultiply213*9356374aSAndroid Build Coastguard Worker   uint128 operator()(uint128 a, uint128 b) const {
214*9356374aSAndroid Build Coastguard Worker     // b hi is always zero because it originated as an int64_t.
215*9356374aSAndroid Build Coastguard Worker     assert(Uint128High64(b) == 0);
216*9356374aSAndroid Build Coastguard Worker     // Fastpath to avoid the expensive overflow check with division.
217*9356374aSAndroid Build Coastguard Worker     if (Uint128High64(a) == 0) {
218*9356374aSAndroid Build Coastguard Worker       return (((Uint128Low64(a) | Uint128Low64(b)) >> 32) == 0)
219*9356374aSAndroid Build Coastguard Worker                  ? static_cast<uint128>(Uint128Low64(a) * Uint128Low64(b))
220*9356374aSAndroid Build Coastguard Worker                  : a * b;
221*9356374aSAndroid Build Coastguard Worker     }
222*9356374aSAndroid Build Coastguard Worker     return b == 0 ? b : (a > Uint128Max() / b) ? Uint128Max() : a * b;
223*9356374aSAndroid Build Coastguard Worker   }
224*9356374aSAndroid Build Coastguard Worker };
225*9356374aSAndroid Build Coastguard Worker 
226*9356374aSAndroid Build Coastguard Worker // Scales (i.e., multiplies or divides, depending on the Operation template)
227*9356374aSAndroid Build Coastguard Worker // the Duration d by the int64_t r.
228*9356374aSAndroid Build Coastguard Worker template <template <typename> class Operation>
ScaleFixed(Duration d,int64_t r)229*9356374aSAndroid Build Coastguard Worker inline Duration ScaleFixed(Duration d, int64_t r) {
230*9356374aSAndroid Build Coastguard Worker   const uint128 a = MakeU128Ticks(d);
231*9356374aSAndroid Build Coastguard Worker   const uint128 b = MakeU128(r);
232*9356374aSAndroid Build Coastguard Worker   const uint128 q = Operation<uint128>()(a, b);
233*9356374aSAndroid Build Coastguard Worker   const bool is_neg = (time_internal::GetRepHi(d) < 0) != (r < 0);
234*9356374aSAndroid Build Coastguard Worker   return MakeDurationFromU128(q, is_neg);
235*9356374aSAndroid Build Coastguard Worker }
236*9356374aSAndroid Build Coastguard Worker 
237*9356374aSAndroid Build Coastguard Worker // Scales (i.e., multiplies or divides, depending on the Operation template)
238*9356374aSAndroid Build Coastguard Worker // the Duration d by the double r.
239*9356374aSAndroid Build Coastguard Worker template <template <typename> class Operation>
ScaleDouble(Duration d,double r)240*9356374aSAndroid Build Coastguard Worker inline Duration ScaleDouble(Duration d, double r) {
241*9356374aSAndroid Build Coastguard Worker   Operation<double> op;
242*9356374aSAndroid Build Coastguard Worker   double hi_doub = op(time_internal::GetRepHi(d), r);
243*9356374aSAndroid Build Coastguard Worker   double lo_doub = op(time_internal::GetRepLo(d), r);
244*9356374aSAndroid Build Coastguard Worker 
245*9356374aSAndroid Build Coastguard Worker   double hi_int = 0;
246*9356374aSAndroid Build Coastguard Worker   double hi_frac = std::modf(hi_doub, &hi_int);
247*9356374aSAndroid Build Coastguard Worker 
248*9356374aSAndroid Build Coastguard Worker   // Moves hi's fractional bits to lo.
249*9356374aSAndroid Build Coastguard Worker   lo_doub /= kTicksPerSecond;
250*9356374aSAndroid Build Coastguard Worker   lo_doub += hi_frac;
251*9356374aSAndroid Build Coastguard Worker 
252*9356374aSAndroid Build Coastguard Worker   double lo_int = 0;
253*9356374aSAndroid Build Coastguard Worker   double lo_frac = std::modf(lo_doub, &lo_int);
254*9356374aSAndroid Build Coastguard Worker 
255*9356374aSAndroid Build Coastguard Worker   // Rolls lo into hi if necessary.
256*9356374aSAndroid Build Coastguard Worker   int64_t lo64 = std::round(lo_frac * kTicksPerSecond);
257*9356374aSAndroid Build Coastguard Worker 
258*9356374aSAndroid Build Coastguard Worker   Duration ans;
259*9356374aSAndroid Build Coastguard Worker   if (!SafeAddRepHi(hi_int, lo_int, &ans)) return ans;
260*9356374aSAndroid Build Coastguard Worker   int64_t hi64 = time_internal::GetRepHi(ans);
261*9356374aSAndroid Build Coastguard Worker   if (!SafeAddRepHi(hi64, lo64 / kTicksPerSecond, &ans)) return ans;
262*9356374aSAndroid Build Coastguard Worker   hi64 = time_internal::GetRepHi(ans);
263*9356374aSAndroid Build Coastguard Worker   lo64 %= kTicksPerSecond;
264*9356374aSAndroid Build Coastguard Worker   NormalizeTicks(&hi64, &lo64);
265*9356374aSAndroid Build Coastguard Worker   return time_internal::MakeDuration(hi64, lo64);
266*9356374aSAndroid Build Coastguard Worker }
267*9356374aSAndroid Build Coastguard Worker 
268*9356374aSAndroid Build Coastguard Worker // Tries to divide num by den as fast as possible by looking for common, easy
269*9356374aSAndroid Build Coastguard Worker // cases. If the division was done, the quotient is in *q and the remainder is
270*9356374aSAndroid Build Coastguard Worker // in *rem and true will be returned.
IDivFastPath(const Duration num,const Duration den,int64_t * q,Duration * rem)271*9356374aSAndroid Build Coastguard Worker inline bool IDivFastPath(const Duration num, const Duration den, int64_t* q,
272*9356374aSAndroid Build Coastguard Worker                          Duration* rem) {
273*9356374aSAndroid Build Coastguard Worker   // Bail if num or den is an infinity.
274*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(num) ||
275*9356374aSAndroid Build Coastguard Worker       time_internal::IsInfiniteDuration(den))
276*9356374aSAndroid Build Coastguard Worker     return false;
277*9356374aSAndroid Build Coastguard Worker 
278*9356374aSAndroid Build Coastguard Worker   int64_t num_hi = time_internal::GetRepHi(num);
279*9356374aSAndroid Build Coastguard Worker   uint32_t num_lo = time_internal::GetRepLo(num);
280*9356374aSAndroid Build Coastguard Worker   int64_t den_hi = time_internal::GetRepHi(den);
281*9356374aSAndroid Build Coastguard Worker   uint32_t den_lo = time_internal::GetRepLo(den);
282*9356374aSAndroid Build Coastguard Worker 
283*9356374aSAndroid Build Coastguard Worker   if (den_hi == 0) {
284*9356374aSAndroid Build Coastguard Worker     if (den_lo == kTicksPerNanosecond) {
285*9356374aSAndroid Build Coastguard Worker       // Dividing by 1ns
286*9356374aSAndroid Build Coastguard Worker       if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000000000) {
287*9356374aSAndroid Build Coastguard Worker         *q = num_hi * 1000000000 + num_lo / kTicksPerNanosecond;
288*9356374aSAndroid Build Coastguard Worker         *rem = time_internal::MakeDuration(0, num_lo % den_lo);
289*9356374aSAndroid Build Coastguard Worker         return true;
290*9356374aSAndroid Build Coastguard Worker       }
291*9356374aSAndroid Build Coastguard Worker     } else if (den_lo == 100 * kTicksPerNanosecond) {
292*9356374aSAndroid Build Coastguard Worker       // Dividing by 100ns (common when converting to Universal time)
293*9356374aSAndroid Build Coastguard Worker       if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 10000000) {
294*9356374aSAndroid Build Coastguard Worker         *q = num_hi * 10000000 + num_lo / (100 * kTicksPerNanosecond);
295*9356374aSAndroid Build Coastguard Worker         *rem = time_internal::MakeDuration(0, num_lo % den_lo);
296*9356374aSAndroid Build Coastguard Worker         return true;
297*9356374aSAndroid Build Coastguard Worker       }
298*9356374aSAndroid Build Coastguard Worker     } else if (den_lo == 1000 * kTicksPerNanosecond) {
299*9356374aSAndroid Build Coastguard Worker       // Dividing by 1us
300*9356374aSAndroid Build Coastguard Worker       if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000000) {
301*9356374aSAndroid Build Coastguard Worker         *q = num_hi * 1000000 + num_lo / (1000 * kTicksPerNanosecond);
302*9356374aSAndroid Build Coastguard Worker         *rem = time_internal::MakeDuration(0, num_lo % den_lo);
303*9356374aSAndroid Build Coastguard Worker         return true;
304*9356374aSAndroid Build Coastguard Worker       }
305*9356374aSAndroid Build Coastguard Worker     } else if (den_lo == 1000000 * kTicksPerNanosecond) {
306*9356374aSAndroid Build Coastguard Worker       // Dividing by 1ms
307*9356374aSAndroid Build Coastguard Worker       if (num_hi >= 0 && num_hi < (kint64max - kTicksPerSecond) / 1000) {
308*9356374aSAndroid Build Coastguard Worker         *q = num_hi * 1000 + num_lo / (1000000 * kTicksPerNanosecond);
309*9356374aSAndroid Build Coastguard Worker         *rem = time_internal::MakeDuration(0, num_lo % den_lo);
310*9356374aSAndroid Build Coastguard Worker         return true;
311*9356374aSAndroid Build Coastguard Worker       }
312*9356374aSAndroid Build Coastguard Worker     }
313*9356374aSAndroid Build Coastguard Worker   } else if (den_hi > 0 && den_lo == 0) {
314*9356374aSAndroid Build Coastguard Worker     // Dividing by positive multiple of 1s
315*9356374aSAndroid Build Coastguard Worker     if (num_hi >= 0) {
316*9356374aSAndroid Build Coastguard Worker       if (den_hi == 1) {
317*9356374aSAndroid Build Coastguard Worker         *q = num_hi;
318*9356374aSAndroid Build Coastguard Worker         *rem = time_internal::MakeDuration(0, num_lo);
319*9356374aSAndroid Build Coastguard Worker         return true;
320*9356374aSAndroid Build Coastguard Worker       }
321*9356374aSAndroid Build Coastguard Worker       *q = num_hi / den_hi;
322*9356374aSAndroid Build Coastguard Worker       *rem = time_internal::MakeDuration(num_hi % den_hi, num_lo);
323*9356374aSAndroid Build Coastguard Worker       return true;
324*9356374aSAndroid Build Coastguard Worker     }
325*9356374aSAndroid Build Coastguard Worker     if (num_lo != 0) {
326*9356374aSAndroid Build Coastguard Worker       num_hi += 1;
327*9356374aSAndroid Build Coastguard Worker     }
328*9356374aSAndroid Build Coastguard Worker     int64_t quotient = num_hi / den_hi;
329*9356374aSAndroid Build Coastguard Worker     int64_t rem_sec = num_hi % den_hi;
330*9356374aSAndroid Build Coastguard Worker     if (rem_sec > 0) {
331*9356374aSAndroid Build Coastguard Worker       rem_sec -= den_hi;
332*9356374aSAndroid Build Coastguard Worker       quotient += 1;
333*9356374aSAndroid Build Coastguard Worker     }
334*9356374aSAndroid Build Coastguard Worker     if (num_lo != 0) {
335*9356374aSAndroid Build Coastguard Worker       rem_sec -= 1;
336*9356374aSAndroid Build Coastguard Worker     }
337*9356374aSAndroid Build Coastguard Worker     *q = quotient;
338*9356374aSAndroid Build Coastguard Worker     *rem = time_internal::MakeDuration(rem_sec, num_lo);
339*9356374aSAndroid Build Coastguard Worker     return true;
340*9356374aSAndroid Build Coastguard Worker   }
341*9356374aSAndroid Build Coastguard Worker 
342*9356374aSAndroid Build Coastguard Worker   return false;
343*9356374aSAndroid Build Coastguard Worker }
344*9356374aSAndroid Build Coastguard Worker 
345*9356374aSAndroid Build Coastguard Worker }  // namespace
346*9356374aSAndroid Build Coastguard Worker 
347*9356374aSAndroid Build Coastguard Worker namespace {
348*9356374aSAndroid Build Coastguard Worker 
IDivSlowPath(bool satq,const Duration num,const Duration den,Duration * rem)349*9356374aSAndroid Build Coastguard Worker int64_t IDivSlowPath(bool satq, const Duration num, const Duration den,
350*9356374aSAndroid Build Coastguard Worker                      Duration* rem) {
351*9356374aSAndroid Build Coastguard Worker   const bool num_neg = num < ZeroDuration();
352*9356374aSAndroid Build Coastguard Worker   const bool den_neg = den < ZeroDuration();
353*9356374aSAndroid Build Coastguard Worker   const bool quotient_neg = num_neg != den_neg;
354*9356374aSAndroid Build Coastguard Worker 
355*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(num) || den == ZeroDuration()) {
356*9356374aSAndroid Build Coastguard Worker     *rem = num_neg ? -InfiniteDuration() : InfiniteDuration();
357*9356374aSAndroid Build Coastguard Worker     return quotient_neg ? kint64min : kint64max;
358*9356374aSAndroid Build Coastguard Worker   }
359*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(den)) {
360*9356374aSAndroid Build Coastguard Worker     *rem = num;
361*9356374aSAndroid Build Coastguard Worker     return 0;
362*9356374aSAndroid Build Coastguard Worker   }
363*9356374aSAndroid Build Coastguard Worker 
364*9356374aSAndroid Build Coastguard Worker   const uint128 a = MakeU128Ticks(num);
365*9356374aSAndroid Build Coastguard Worker   const uint128 b = MakeU128Ticks(den);
366*9356374aSAndroid Build Coastguard Worker   uint128 quotient128 = a / b;
367*9356374aSAndroid Build Coastguard Worker 
368*9356374aSAndroid Build Coastguard Worker   if (satq) {
369*9356374aSAndroid Build Coastguard Worker     // Limits the quotient to the range of int64_t.
370*9356374aSAndroid Build Coastguard Worker     if (quotient128 > uint128(static_cast<uint64_t>(kint64max))) {
371*9356374aSAndroid Build Coastguard Worker       quotient128 = quotient_neg ? uint128(static_cast<uint64_t>(kint64min))
372*9356374aSAndroid Build Coastguard Worker                                  : uint128(static_cast<uint64_t>(kint64max));
373*9356374aSAndroid Build Coastguard Worker     }
374*9356374aSAndroid Build Coastguard Worker   }
375*9356374aSAndroid Build Coastguard Worker 
376*9356374aSAndroid Build Coastguard Worker   const uint128 remainder128 = a - quotient128 * b;
377*9356374aSAndroid Build Coastguard Worker   *rem = MakeDurationFromU128(remainder128, num_neg);
378*9356374aSAndroid Build Coastguard Worker 
379*9356374aSAndroid Build Coastguard Worker   if (!quotient_neg || quotient128 == 0) {
380*9356374aSAndroid Build Coastguard Worker     return Uint128Low64(quotient128) & kint64max;
381*9356374aSAndroid Build Coastguard Worker   }
382*9356374aSAndroid Build Coastguard Worker   // The quotient needs to be negated, but we need to carefully handle
383*9356374aSAndroid Build Coastguard Worker   // quotient128s with the top bit on.
384*9356374aSAndroid Build Coastguard Worker   return -static_cast<int64_t>(Uint128Low64(quotient128 - 1) & kint64max) - 1;
385*9356374aSAndroid Build Coastguard Worker }
386*9356374aSAndroid Build Coastguard Worker 
387*9356374aSAndroid Build Coastguard Worker // The 'satq' argument indicates whether the quotient should saturate at the
388*9356374aSAndroid Build Coastguard Worker // bounds of int64_t.  If it does saturate, the difference will spill over to
389*9356374aSAndroid Build Coastguard Worker // the remainder.  If it does not saturate, the remainder remain accurate,
390*9356374aSAndroid Build Coastguard Worker // but the returned quotient will over/underflow int64_t and should not be used.
IDivDurationImpl(bool satq,const Duration num,const Duration den,Duration * rem)391*9356374aSAndroid Build Coastguard Worker ABSL_ATTRIBUTE_ALWAYS_INLINE inline int64_t IDivDurationImpl(bool satq,
392*9356374aSAndroid Build Coastguard Worker                                                              const Duration num,
393*9356374aSAndroid Build Coastguard Worker                                                              const Duration den,
394*9356374aSAndroid Build Coastguard Worker                                                              Duration* rem) {
395*9356374aSAndroid Build Coastguard Worker   int64_t q = 0;
396*9356374aSAndroid Build Coastguard Worker   if (IDivFastPath(num, den, &q, rem)) {
397*9356374aSAndroid Build Coastguard Worker     return q;
398*9356374aSAndroid Build Coastguard Worker   }
399*9356374aSAndroid Build Coastguard Worker   return IDivSlowPath(satq, num, den, rem);
400*9356374aSAndroid Build Coastguard Worker }
401*9356374aSAndroid Build Coastguard Worker 
402*9356374aSAndroid Build Coastguard Worker }  // namespace
403*9356374aSAndroid Build Coastguard Worker 
IDivDuration(Duration num,Duration den,Duration * rem)404*9356374aSAndroid Build Coastguard Worker int64_t IDivDuration(Duration num, Duration den, Duration* rem) {
405*9356374aSAndroid Build Coastguard Worker   return IDivDurationImpl(true, num, den,
406*9356374aSAndroid Build Coastguard Worker                           rem);  // trunc towards zero
407*9356374aSAndroid Build Coastguard Worker }
408*9356374aSAndroid Build Coastguard Worker 
409*9356374aSAndroid Build Coastguard Worker //
410*9356374aSAndroid Build Coastguard Worker // Additive operators.
411*9356374aSAndroid Build Coastguard Worker //
412*9356374aSAndroid Build Coastguard Worker 
operator +=(Duration rhs)413*9356374aSAndroid Build Coastguard Worker Duration& Duration::operator+=(Duration rhs) {
414*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(*this)) return *this;
415*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(rhs)) return *this = rhs;
416*9356374aSAndroid Build Coastguard Worker   const int64_t orig_rep_hi = rep_hi_.Get();
417*9356374aSAndroid Build Coastguard Worker   rep_hi_ = DecodeTwosComp(EncodeTwosComp(rep_hi_.Get()) +
418*9356374aSAndroid Build Coastguard Worker                            EncodeTwosComp(rhs.rep_hi_.Get()));
419*9356374aSAndroid Build Coastguard Worker   if (rep_lo_ >= kTicksPerSecond - rhs.rep_lo_) {
420*9356374aSAndroid Build Coastguard Worker     rep_hi_ = DecodeTwosComp(EncodeTwosComp(rep_hi_.Get()) + 1);
421*9356374aSAndroid Build Coastguard Worker     rep_lo_ -= kTicksPerSecond;
422*9356374aSAndroid Build Coastguard Worker   }
423*9356374aSAndroid Build Coastguard Worker   rep_lo_ += rhs.rep_lo_;
424*9356374aSAndroid Build Coastguard Worker   if (rhs.rep_hi_.Get() < 0 ? rep_hi_.Get() > orig_rep_hi
425*9356374aSAndroid Build Coastguard Worker                             : rep_hi_.Get() < orig_rep_hi) {
426*9356374aSAndroid Build Coastguard Worker     return *this =
427*9356374aSAndroid Build Coastguard Worker                rhs.rep_hi_.Get() < 0 ? -InfiniteDuration() : InfiniteDuration();
428*9356374aSAndroid Build Coastguard Worker   }
429*9356374aSAndroid Build Coastguard Worker   return *this;
430*9356374aSAndroid Build Coastguard Worker }
431*9356374aSAndroid Build Coastguard Worker 
operator -=(Duration rhs)432*9356374aSAndroid Build Coastguard Worker Duration& Duration::operator-=(Duration rhs) {
433*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(*this)) return *this;
434*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(rhs)) {
435*9356374aSAndroid Build Coastguard Worker     return *this = rhs.rep_hi_.Get() >= 0 ? -InfiniteDuration()
436*9356374aSAndroid Build Coastguard Worker                                           : InfiniteDuration();
437*9356374aSAndroid Build Coastguard Worker   }
438*9356374aSAndroid Build Coastguard Worker   const int64_t orig_rep_hi = rep_hi_.Get();
439*9356374aSAndroid Build Coastguard Worker   rep_hi_ = DecodeTwosComp(EncodeTwosComp(rep_hi_.Get()) -
440*9356374aSAndroid Build Coastguard Worker                            EncodeTwosComp(rhs.rep_hi_.Get()));
441*9356374aSAndroid Build Coastguard Worker   if (rep_lo_ < rhs.rep_lo_) {
442*9356374aSAndroid Build Coastguard Worker     rep_hi_ = DecodeTwosComp(EncodeTwosComp(rep_hi_.Get()) - 1);
443*9356374aSAndroid Build Coastguard Worker     rep_lo_ += kTicksPerSecond;
444*9356374aSAndroid Build Coastguard Worker   }
445*9356374aSAndroid Build Coastguard Worker   rep_lo_ -= rhs.rep_lo_;
446*9356374aSAndroid Build Coastguard Worker   if (rhs.rep_hi_.Get() < 0 ? rep_hi_.Get() < orig_rep_hi
447*9356374aSAndroid Build Coastguard Worker                             : rep_hi_.Get() > orig_rep_hi) {
448*9356374aSAndroid Build Coastguard Worker     return *this = rhs.rep_hi_.Get() >= 0 ? -InfiniteDuration()
449*9356374aSAndroid Build Coastguard Worker                                           : InfiniteDuration();
450*9356374aSAndroid Build Coastguard Worker   }
451*9356374aSAndroid Build Coastguard Worker   return *this;
452*9356374aSAndroid Build Coastguard Worker }
453*9356374aSAndroid Build Coastguard Worker 
454*9356374aSAndroid Build Coastguard Worker //
455*9356374aSAndroid Build Coastguard Worker // Multiplicative operators.
456*9356374aSAndroid Build Coastguard Worker //
457*9356374aSAndroid Build Coastguard Worker 
operator *=(int64_t r)458*9356374aSAndroid Build Coastguard Worker Duration& Duration::operator*=(int64_t r) {
459*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(*this)) {
460*9356374aSAndroid Build Coastguard Worker     const bool is_neg = (r < 0) != (rep_hi_.Get() < 0);
461*9356374aSAndroid Build Coastguard Worker     return *this = is_neg ? -InfiniteDuration() : InfiniteDuration();
462*9356374aSAndroid Build Coastguard Worker   }
463*9356374aSAndroid Build Coastguard Worker   return *this = ScaleFixed<SafeMultiply>(*this, r);
464*9356374aSAndroid Build Coastguard Worker }
465*9356374aSAndroid Build Coastguard Worker 
operator *=(double r)466*9356374aSAndroid Build Coastguard Worker Duration& Duration::operator*=(double r) {
467*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(*this) || !IsFinite(r)) {
468*9356374aSAndroid Build Coastguard Worker     const bool is_neg = std::signbit(r) != (rep_hi_.Get() < 0);
469*9356374aSAndroid Build Coastguard Worker     return *this = is_neg ? -InfiniteDuration() : InfiniteDuration();
470*9356374aSAndroid Build Coastguard Worker   }
471*9356374aSAndroid Build Coastguard Worker   return *this = ScaleDouble<std::multiplies>(*this, r);
472*9356374aSAndroid Build Coastguard Worker }
473*9356374aSAndroid Build Coastguard Worker 
operator /=(int64_t r)474*9356374aSAndroid Build Coastguard Worker Duration& Duration::operator/=(int64_t r) {
475*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(*this) || r == 0) {
476*9356374aSAndroid Build Coastguard Worker     const bool is_neg = (r < 0) != (rep_hi_.Get() < 0);
477*9356374aSAndroid Build Coastguard Worker     return *this = is_neg ? -InfiniteDuration() : InfiniteDuration();
478*9356374aSAndroid Build Coastguard Worker   }
479*9356374aSAndroid Build Coastguard Worker   return *this = ScaleFixed<std::divides>(*this, r);
480*9356374aSAndroid Build Coastguard Worker }
481*9356374aSAndroid Build Coastguard Worker 
operator /=(double r)482*9356374aSAndroid Build Coastguard Worker Duration& Duration::operator/=(double r) {
483*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(*this) || !IsValidDivisor(r)) {
484*9356374aSAndroid Build Coastguard Worker     const bool is_neg = std::signbit(r) != (rep_hi_.Get() < 0);
485*9356374aSAndroid Build Coastguard Worker     return *this = is_neg ? -InfiniteDuration() : InfiniteDuration();
486*9356374aSAndroid Build Coastguard Worker   }
487*9356374aSAndroid Build Coastguard Worker   return *this = ScaleDouble<std::divides>(*this, r);
488*9356374aSAndroid Build Coastguard Worker }
489*9356374aSAndroid Build Coastguard Worker 
operator %=(Duration rhs)490*9356374aSAndroid Build Coastguard Worker Duration& Duration::operator%=(Duration rhs) {
491*9356374aSAndroid Build Coastguard Worker   IDivDurationImpl(false, *this, rhs, this);
492*9356374aSAndroid Build Coastguard Worker   return *this;
493*9356374aSAndroid Build Coastguard Worker }
494*9356374aSAndroid Build Coastguard Worker 
FDivDuration(Duration num,Duration den)495*9356374aSAndroid Build Coastguard Worker double FDivDuration(Duration num, Duration den) {
496*9356374aSAndroid Build Coastguard Worker   // Arithmetic with infinity is sticky.
497*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(num) || den == ZeroDuration()) {
498*9356374aSAndroid Build Coastguard Worker     return (num < ZeroDuration()) == (den < ZeroDuration())
499*9356374aSAndroid Build Coastguard Worker                ? std::numeric_limits<double>::infinity()
500*9356374aSAndroid Build Coastguard Worker                : -std::numeric_limits<double>::infinity();
501*9356374aSAndroid Build Coastguard Worker   }
502*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(den)) return 0.0;
503*9356374aSAndroid Build Coastguard Worker 
504*9356374aSAndroid Build Coastguard Worker   double a =
505*9356374aSAndroid Build Coastguard Worker       static_cast<double>(time_internal::GetRepHi(num)) * kTicksPerSecond +
506*9356374aSAndroid Build Coastguard Worker       time_internal::GetRepLo(num);
507*9356374aSAndroid Build Coastguard Worker   double b =
508*9356374aSAndroid Build Coastguard Worker       static_cast<double>(time_internal::GetRepHi(den)) * kTicksPerSecond +
509*9356374aSAndroid Build Coastguard Worker       time_internal::GetRepLo(den);
510*9356374aSAndroid Build Coastguard Worker   return a / b;
511*9356374aSAndroid Build Coastguard Worker }
512*9356374aSAndroid Build Coastguard Worker 
513*9356374aSAndroid Build Coastguard Worker //
514*9356374aSAndroid Build Coastguard Worker // Trunc/Floor/Ceil.
515*9356374aSAndroid Build Coastguard Worker //
516*9356374aSAndroid Build Coastguard Worker 
Trunc(Duration d,Duration unit)517*9356374aSAndroid Build Coastguard Worker Duration Trunc(Duration d, Duration unit) { return d - (d % unit); }
518*9356374aSAndroid Build Coastguard Worker 
Floor(const Duration d,const Duration unit)519*9356374aSAndroid Build Coastguard Worker Duration Floor(const Duration d, const Duration unit) {
520*9356374aSAndroid Build Coastguard Worker   const absl::Duration td = Trunc(d, unit);
521*9356374aSAndroid Build Coastguard Worker   return td <= d ? td : td - AbsDuration(unit);
522*9356374aSAndroid Build Coastguard Worker }
523*9356374aSAndroid Build Coastguard Worker 
Ceil(const Duration d,const Duration unit)524*9356374aSAndroid Build Coastguard Worker Duration Ceil(const Duration d, const Duration unit) {
525*9356374aSAndroid Build Coastguard Worker   const absl::Duration td = Trunc(d, unit);
526*9356374aSAndroid Build Coastguard Worker   return td >= d ? td : td + AbsDuration(unit);
527*9356374aSAndroid Build Coastguard Worker }
528*9356374aSAndroid Build Coastguard Worker 
529*9356374aSAndroid Build Coastguard Worker //
530*9356374aSAndroid Build Coastguard Worker // Factory functions.
531*9356374aSAndroid Build Coastguard Worker //
532*9356374aSAndroid Build Coastguard Worker 
DurationFromTimespec(timespec ts)533*9356374aSAndroid Build Coastguard Worker Duration DurationFromTimespec(timespec ts) {
534*9356374aSAndroid Build Coastguard Worker   if (static_cast<uint64_t>(ts.tv_nsec) < 1000 * 1000 * 1000) {
535*9356374aSAndroid Build Coastguard Worker     int64_t ticks = ts.tv_nsec * kTicksPerNanosecond;
536*9356374aSAndroid Build Coastguard Worker     return time_internal::MakeDuration(ts.tv_sec, ticks);
537*9356374aSAndroid Build Coastguard Worker   }
538*9356374aSAndroid Build Coastguard Worker   return Seconds(ts.tv_sec) + Nanoseconds(ts.tv_nsec);
539*9356374aSAndroid Build Coastguard Worker }
540*9356374aSAndroid Build Coastguard Worker 
DurationFromTimeval(timeval tv)541*9356374aSAndroid Build Coastguard Worker Duration DurationFromTimeval(timeval tv) {
542*9356374aSAndroid Build Coastguard Worker   if (static_cast<uint64_t>(tv.tv_usec) < 1000 * 1000) {
543*9356374aSAndroid Build Coastguard Worker     int64_t ticks = tv.tv_usec * 1000 * kTicksPerNanosecond;
544*9356374aSAndroid Build Coastguard Worker     return time_internal::MakeDuration(tv.tv_sec, ticks);
545*9356374aSAndroid Build Coastguard Worker   }
546*9356374aSAndroid Build Coastguard Worker   return Seconds(tv.tv_sec) + Microseconds(tv.tv_usec);
547*9356374aSAndroid Build Coastguard Worker }
548*9356374aSAndroid Build Coastguard Worker 
549*9356374aSAndroid Build Coastguard Worker //
550*9356374aSAndroid Build Coastguard Worker // Conversion to other duration types.
551*9356374aSAndroid Build Coastguard Worker //
552*9356374aSAndroid Build Coastguard Worker 
ToInt64Nanoseconds(Duration d)553*9356374aSAndroid Build Coastguard Worker int64_t ToInt64Nanoseconds(Duration d) {
554*9356374aSAndroid Build Coastguard Worker   if (time_internal::GetRepHi(d) >= 0 &&
555*9356374aSAndroid Build Coastguard Worker       time_internal::GetRepHi(d) >> 33 == 0) {
556*9356374aSAndroid Build Coastguard Worker     return (time_internal::GetRepHi(d) * 1000 * 1000 * 1000) +
557*9356374aSAndroid Build Coastguard Worker            (time_internal::GetRepLo(d) / kTicksPerNanosecond);
558*9356374aSAndroid Build Coastguard Worker   }
559*9356374aSAndroid Build Coastguard Worker   return d / Nanoseconds(1);
560*9356374aSAndroid Build Coastguard Worker }
ToInt64Microseconds(Duration d)561*9356374aSAndroid Build Coastguard Worker int64_t ToInt64Microseconds(Duration d) {
562*9356374aSAndroid Build Coastguard Worker   if (time_internal::GetRepHi(d) >= 0 &&
563*9356374aSAndroid Build Coastguard Worker       time_internal::GetRepHi(d) >> 43 == 0) {
564*9356374aSAndroid Build Coastguard Worker     return (time_internal::GetRepHi(d) * 1000 * 1000) +
565*9356374aSAndroid Build Coastguard Worker            (time_internal::GetRepLo(d) / (kTicksPerNanosecond * 1000));
566*9356374aSAndroid Build Coastguard Worker   }
567*9356374aSAndroid Build Coastguard Worker   return d / Microseconds(1);
568*9356374aSAndroid Build Coastguard Worker }
ToInt64Milliseconds(Duration d)569*9356374aSAndroid Build Coastguard Worker int64_t ToInt64Milliseconds(Duration d) {
570*9356374aSAndroid Build Coastguard Worker   if (time_internal::GetRepHi(d) >= 0 &&
571*9356374aSAndroid Build Coastguard Worker       time_internal::GetRepHi(d) >> 53 == 0) {
572*9356374aSAndroid Build Coastguard Worker     return (time_internal::GetRepHi(d) * 1000) +
573*9356374aSAndroid Build Coastguard Worker            (time_internal::GetRepLo(d) / (kTicksPerNanosecond * 1000 * 1000));
574*9356374aSAndroid Build Coastguard Worker   }
575*9356374aSAndroid Build Coastguard Worker   return d / Milliseconds(1);
576*9356374aSAndroid Build Coastguard Worker }
ToInt64Seconds(Duration d)577*9356374aSAndroid Build Coastguard Worker int64_t ToInt64Seconds(Duration d) {
578*9356374aSAndroid Build Coastguard Worker   int64_t hi = time_internal::GetRepHi(d);
579*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(d)) return hi;
580*9356374aSAndroid Build Coastguard Worker   if (hi < 0 && time_internal::GetRepLo(d) != 0) ++hi;
581*9356374aSAndroid Build Coastguard Worker   return hi;
582*9356374aSAndroid Build Coastguard Worker }
ToInt64Minutes(Duration d)583*9356374aSAndroid Build Coastguard Worker int64_t ToInt64Minutes(Duration d) {
584*9356374aSAndroid Build Coastguard Worker   int64_t hi = time_internal::GetRepHi(d);
585*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(d)) return hi;
586*9356374aSAndroid Build Coastguard Worker   if (hi < 0 && time_internal::GetRepLo(d) != 0) ++hi;
587*9356374aSAndroid Build Coastguard Worker   return hi / 60;
588*9356374aSAndroid Build Coastguard Worker }
ToInt64Hours(Duration d)589*9356374aSAndroid Build Coastguard Worker int64_t ToInt64Hours(Duration d) {
590*9356374aSAndroid Build Coastguard Worker   int64_t hi = time_internal::GetRepHi(d);
591*9356374aSAndroid Build Coastguard Worker   if (time_internal::IsInfiniteDuration(d)) return hi;
592*9356374aSAndroid Build Coastguard Worker   if (hi < 0 && time_internal::GetRepLo(d) != 0) ++hi;
593*9356374aSAndroid Build Coastguard Worker   return hi / (60 * 60);
594*9356374aSAndroid Build Coastguard Worker }
595*9356374aSAndroid Build Coastguard Worker 
ToDoubleNanoseconds(Duration d)596*9356374aSAndroid Build Coastguard Worker double ToDoubleNanoseconds(Duration d) {
597*9356374aSAndroid Build Coastguard Worker   return FDivDuration(d, Nanoseconds(1));
598*9356374aSAndroid Build Coastguard Worker }
ToDoubleMicroseconds(Duration d)599*9356374aSAndroid Build Coastguard Worker double ToDoubleMicroseconds(Duration d) {
600*9356374aSAndroid Build Coastguard Worker   return FDivDuration(d, Microseconds(1));
601*9356374aSAndroid Build Coastguard Worker }
ToDoubleMilliseconds(Duration d)602*9356374aSAndroid Build Coastguard Worker double ToDoubleMilliseconds(Duration d) {
603*9356374aSAndroid Build Coastguard Worker   return FDivDuration(d, Milliseconds(1));
604*9356374aSAndroid Build Coastguard Worker }
ToDoubleSeconds(Duration d)605*9356374aSAndroid Build Coastguard Worker double ToDoubleSeconds(Duration d) { return FDivDuration(d, Seconds(1)); }
ToDoubleMinutes(Duration d)606*9356374aSAndroid Build Coastguard Worker double ToDoubleMinutes(Duration d) { return FDivDuration(d, Minutes(1)); }
ToDoubleHours(Duration d)607*9356374aSAndroid Build Coastguard Worker double ToDoubleHours(Duration d) { return FDivDuration(d, Hours(1)); }
608*9356374aSAndroid Build Coastguard Worker 
ToTimespec(Duration d)609*9356374aSAndroid Build Coastguard Worker timespec ToTimespec(Duration d) {
610*9356374aSAndroid Build Coastguard Worker   timespec ts;
611*9356374aSAndroid Build Coastguard Worker   if (!time_internal::IsInfiniteDuration(d)) {
612*9356374aSAndroid Build Coastguard Worker     int64_t rep_hi = time_internal::GetRepHi(d);
613*9356374aSAndroid Build Coastguard Worker     uint32_t rep_lo = time_internal::GetRepLo(d);
614*9356374aSAndroid Build Coastguard Worker     if (rep_hi < 0) {
615*9356374aSAndroid Build Coastguard Worker       // Tweak the fields so that unsigned division of rep_lo
616*9356374aSAndroid Build Coastguard Worker       // maps to truncation (towards zero) for the timespec.
617*9356374aSAndroid Build Coastguard Worker       rep_lo += kTicksPerNanosecond - 1;
618*9356374aSAndroid Build Coastguard Worker       if (rep_lo >= kTicksPerSecond) {
619*9356374aSAndroid Build Coastguard Worker         rep_hi += 1;
620*9356374aSAndroid Build Coastguard Worker         rep_lo -= kTicksPerSecond;
621*9356374aSAndroid Build Coastguard Worker       }
622*9356374aSAndroid Build Coastguard Worker     }
623*9356374aSAndroid Build Coastguard Worker     ts.tv_sec = static_cast<decltype(ts.tv_sec)>(rep_hi);
624*9356374aSAndroid Build Coastguard Worker     if (ts.tv_sec == rep_hi) {  // no time_t narrowing
625*9356374aSAndroid Build Coastguard Worker       ts.tv_nsec = rep_lo / kTicksPerNanosecond;
626*9356374aSAndroid Build Coastguard Worker       return ts;
627*9356374aSAndroid Build Coastguard Worker     }
628*9356374aSAndroid Build Coastguard Worker   }
629*9356374aSAndroid Build Coastguard Worker   if (d >= ZeroDuration()) {
630*9356374aSAndroid Build Coastguard Worker     ts.tv_sec = std::numeric_limits<time_t>::max();
631*9356374aSAndroid Build Coastguard Worker     ts.tv_nsec = 1000 * 1000 * 1000 - 1;
632*9356374aSAndroid Build Coastguard Worker   } else {
633*9356374aSAndroid Build Coastguard Worker     ts.tv_sec = std::numeric_limits<time_t>::min();
634*9356374aSAndroid Build Coastguard Worker     ts.tv_nsec = 0;
635*9356374aSAndroid Build Coastguard Worker   }
636*9356374aSAndroid Build Coastguard Worker   return ts;
637*9356374aSAndroid Build Coastguard Worker }
638*9356374aSAndroid Build Coastguard Worker 
ToTimeval(Duration d)639*9356374aSAndroid Build Coastguard Worker timeval ToTimeval(Duration d) {
640*9356374aSAndroid Build Coastguard Worker   timeval tv;
641*9356374aSAndroid Build Coastguard Worker   timespec ts = ToTimespec(d);
642*9356374aSAndroid Build Coastguard Worker   if (ts.tv_sec < 0) {
643*9356374aSAndroid Build Coastguard Worker     // Tweak the fields so that positive division of tv_nsec
644*9356374aSAndroid Build Coastguard Worker     // maps to truncation (towards zero) for the timeval.
645*9356374aSAndroid Build Coastguard Worker     ts.tv_nsec += 1000 - 1;
646*9356374aSAndroid Build Coastguard Worker     if (ts.tv_nsec >= 1000 * 1000 * 1000) {
647*9356374aSAndroid Build Coastguard Worker       ts.tv_sec += 1;
648*9356374aSAndroid Build Coastguard Worker       ts.tv_nsec -= 1000 * 1000 * 1000;
649*9356374aSAndroid Build Coastguard Worker     }
650*9356374aSAndroid Build Coastguard Worker   }
651*9356374aSAndroid Build Coastguard Worker   tv.tv_sec = static_cast<decltype(tv.tv_sec)>(ts.tv_sec);
652*9356374aSAndroid Build Coastguard Worker   if (tv.tv_sec != ts.tv_sec) {  // narrowing
653*9356374aSAndroid Build Coastguard Worker     if (ts.tv_sec < 0) {
654*9356374aSAndroid Build Coastguard Worker       tv.tv_sec = std::numeric_limits<decltype(tv.tv_sec)>::min();
655*9356374aSAndroid Build Coastguard Worker       tv.tv_usec = 0;
656*9356374aSAndroid Build Coastguard Worker     } else {
657*9356374aSAndroid Build Coastguard Worker       tv.tv_sec = std::numeric_limits<decltype(tv.tv_sec)>::max();
658*9356374aSAndroid Build Coastguard Worker       tv.tv_usec = 1000 * 1000 - 1;
659*9356374aSAndroid Build Coastguard Worker     }
660*9356374aSAndroid Build Coastguard Worker     return tv;
661*9356374aSAndroid Build Coastguard Worker   }
662*9356374aSAndroid Build Coastguard Worker   tv.tv_usec = static_cast<int>(ts.tv_nsec / 1000);  // suseconds_t
663*9356374aSAndroid Build Coastguard Worker   return tv;
664*9356374aSAndroid Build Coastguard Worker }
665*9356374aSAndroid Build Coastguard Worker 
ToChronoNanoseconds(Duration d)666*9356374aSAndroid Build Coastguard Worker std::chrono::nanoseconds ToChronoNanoseconds(Duration d) {
667*9356374aSAndroid Build Coastguard Worker   return time_internal::ToChronoDuration<std::chrono::nanoseconds>(d);
668*9356374aSAndroid Build Coastguard Worker }
ToChronoMicroseconds(Duration d)669*9356374aSAndroid Build Coastguard Worker std::chrono::microseconds ToChronoMicroseconds(Duration d) {
670*9356374aSAndroid Build Coastguard Worker   return time_internal::ToChronoDuration<std::chrono::microseconds>(d);
671*9356374aSAndroid Build Coastguard Worker }
ToChronoMilliseconds(Duration d)672*9356374aSAndroid Build Coastguard Worker std::chrono::milliseconds ToChronoMilliseconds(Duration d) {
673*9356374aSAndroid Build Coastguard Worker   return time_internal::ToChronoDuration<std::chrono::milliseconds>(d);
674*9356374aSAndroid Build Coastguard Worker }
ToChronoSeconds(Duration d)675*9356374aSAndroid Build Coastguard Worker std::chrono::seconds ToChronoSeconds(Duration d) {
676*9356374aSAndroid Build Coastguard Worker   return time_internal::ToChronoDuration<std::chrono::seconds>(d);
677*9356374aSAndroid Build Coastguard Worker }
ToChronoMinutes(Duration d)678*9356374aSAndroid Build Coastguard Worker std::chrono::minutes ToChronoMinutes(Duration d) {
679*9356374aSAndroid Build Coastguard Worker   return time_internal::ToChronoDuration<std::chrono::minutes>(d);
680*9356374aSAndroid Build Coastguard Worker }
ToChronoHours(Duration d)681*9356374aSAndroid Build Coastguard Worker std::chrono::hours ToChronoHours(Duration d) {
682*9356374aSAndroid Build Coastguard Worker   return time_internal::ToChronoDuration<std::chrono::hours>(d);
683*9356374aSAndroid Build Coastguard Worker }
684*9356374aSAndroid Build Coastguard Worker 
685*9356374aSAndroid Build Coastguard Worker //
686*9356374aSAndroid Build Coastguard Worker // To/From string formatting.
687*9356374aSAndroid Build Coastguard Worker //
688*9356374aSAndroid Build Coastguard Worker 
689*9356374aSAndroid Build Coastguard Worker namespace {
690*9356374aSAndroid Build Coastguard Worker 
691*9356374aSAndroid Build Coastguard Worker // Formats a positive 64-bit integer in the given field width.  Note that
692*9356374aSAndroid Build Coastguard Worker // it is up to the caller of Format64() to ensure that there is sufficient
693*9356374aSAndroid Build Coastguard Worker // space before ep to hold the conversion.
Format64(char * ep,int width,int64_t v)694*9356374aSAndroid Build Coastguard Worker char* Format64(char* ep, int width, int64_t v) {
695*9356374aSAndroid Build Coastguard Worker   do {
696*9356374aSAndroid Build Coastguard Worker     --width;
697*9356374aSAndroid Build Coastguard Worker     *--ep = static_cast<char>('0' + (v % 10));  // contiguous digits
698*9356374aSAndroid Build Coastguard Worker   } while (v /= 10);
699*9356374aSAndroid Build Coastguard Worker   while (--width >= 0) *--ep = '0';  // zero pad
700*9356374aSAndroid Build Coastguard Worker   return ep;
701*9356374aSAndroid Build Coastguard Worker }
702*9356374aSAndroid Build Coastguard Worker 
703*9356374aSAndroid Build Coastguard Worker // Helpers for FormatDuration() that format 'n' and append it to 'out'
704*9356374aSAndroid Build Coastguard Worker // followed by the given 'unit'.  If 'n' formats to "0", nothing is
705*9356374aSAndroid Build Coastguard Worker // appended (not even the unit).
706*9356374aSAndroid Build Coastguard Worker 
707*9356374aSAndroid Build Coastguard Worker // A type that encapsulates how to display a value of a particular unit. For
708*9356374aSAndroid Build Coastguard Worker // values that are displayed with fractional parts, the precision indicates
709*9356374aSAndroid Build Coastguard Worker // where to round the value. The precision varies with the display unit because
710*9356374aSAndroid Build Coastguard Worker // a Duration can hold only quarters of a nanosecond, so displaying information
711*9356374aSAndroid Build Coastguard Worker // beyond that is just noise.
712*9356374aSAndroid Build Coastguard Worker //
713*9356374aSAndroid Build Coastguard Worker // For example, a microsecond value of 42.00025xxxxx should not display beyond 5
714*9356374aSAndroid Build Coastguard Worker // fractional digits, because it is in the noise of what a Duration can
715*9356374aSAndroid Build Coastguard Worker // represent.
716*9356374aSAndroid Build Coastguard Worker struct DisplayUnit {
717*9356374aSAndroid Build Coastguard Worker   absl::string_view abbr;
718*9356374aSAndroid Build Coastguard Worker   int prec;
719*9356374aSAndroid Build Coastguard Worker   double pow10;
720*9356374aSAndroid Build Coastguard Worker };
721*9356374aSAndroid Build Coastguard Worker ABSL_CONST_INIT const DisplayUnit kDisplayNano = {"ns", 2, 1e2};
722*9356374aSAndroid Build Coastguard Worker ABSL_CONST_INIT const DisplayUnit kDisplayMicro = {"us", 5, 1e5};
723*9356374aSAndroid Build Coastguard Worker ABSL_CONST_INIT const DisplayUnit kDisplayMilli = {"ms", 8, 1e8};
724*9356374aSAndroid Build Coastguard Worker ABSL_CONST_INIT const DisplayUnit kDisplaySec = {"s", 11, 1e11};
725*9356374aSAndroid Build Coastguard Worker ABSL_CONST_INIT const DisplayUnit kDisplayMin = {"m", -1, 0.0};  // prec ignored
726*9356374aSAndroid Build Coastguard Worker ABSL_CONST_INIT const DisplayUnit kDisplayHour = {"h", -1,
727*9356374aSAndroid Build Coastguard Worker                                                   0.0};  // prec ignored
728*9356374aSAndroid Build Coastguard Worker 
AppendNumberUnit(std::string * out,int64_t n,DisplayUnit unit)729*9356374aSAndroid Build Coastguard Worker void AppendNumberUnit(std::string* out, int64_t n, DisplayUnit unit) {
730*9356374aSAndroid Build Coastguard Worker   char buf[sizeof("2562047788015216")];  // hours in max duration
731*9356374aSAndroid Build Coastguard Worker   char* const ep = buf + sizeof(buf);
732*9356374aSAndroid Build Coastguard Worker   char* bp = Format64(ep, 0, n);
733*9356374aSAndroid Build Coastguard Worker   if (*bp != '0' || bp + 1 != ep) {
734*9356374aSAndroid Build Coastguard Worker     out->append(bp, static_cast<size_t>(ep - bp));
735*9356374aSAndroid Build Coastguard Worker     out->append(unit.abbr.data(), unit.abbr.size());
736*9356374aSAndroid Build Coastguard Worker   }
737*9356374aSAndroid Build Coastguard Worker }
738*9356374aSAndroid Build Coastguard Worker 
739*9356374aSAndroid Build Coastguard Worker // Note: unit.prec is limited to double's digits10 value (typically 15) so it
740*9356374aSAndroid Build Coastguard Worker // always fits in buf[].
AppendNumberUnit(std::string * out,double n,DisplayUnit unit)741*9356374aSAndroid Build Coastguard Worker void AppendNumberUnit(std::string* out, double n, DisplayUnit unit) {
742*9356374aSAndroid Build Coastguard Worker   constexpr int kBufferSize = std::numeric_limits<double>::digits10;
743*9356374aSAndroid Build Coastguard Worker   const int prec = std::min(kBufferSize, unit.prec);
744*9356374aSAndroid Build Coastguard Worker   char buf[kBufferSize];  // also large enough to hold integer part
745*9356374aSAndroid Build Coastguard Worker   char* ep = buf + sizeof(buf);
746*9356374aSAndroid Build Coastguard Worker   double d = 0;
747*9356374aSAndroid Build Coastguard Worker   int64_t frac_part = std::round(std::modf(n, &d) * unit.pow10);
748*9356374aSAndroid Build Coastguard Worker   int64_t int_part = d;
749*9356374aSAndroid Build Coastguard Worker   if (int_part != 0 || frac_part != 0) {
750*9356374aSAndroid Build Coastguard Worker     char* bp = Format64(ep, 0, int_part);  // always < 1000
751*9356374aSAndroid Build Coastguard Worker     out->append(bp, static_cast<size_t>(ep - bp));
752*9356374aSAndroid Build Coastguard Worker     if (frac_part != 0) {
753*9356374aSAndroid Build Coastguard Worker       out->push_back('.');
754*9356374aSAndroid Build Coastguard Worker       bp = Format64(ep, prec, frac_part);
755*9356374aSAndroid Build Coastguard Worker       while (ep[-1] == '0') --ep;
756*9356374aSAndroid Build Coastguard Worker       out->append(bp, static_cast<size_t>(ep - bp));
757*9356374aSAndroid Build Coastguard Worker     }
758*9356374aSAndroid Build Coastguard Worker     out->append(unit.abbr.data(), unit.abbr.size());
759*9356374aSAndroid Build Coastguard Worker   }
760*9356374aSAndroid Build Coastguard Worker }
761*9356374aSAndroid Build Coastguard Worker 
762*9356374aSAndroid Build Coastguard Worker }  // namespace
763*9356374aSAndroid Build Coastguard Worker 
764*9356374aSAndroid Build Coastguard Worker // From Go's doc at https://golang.org/pkg/time/#Duration.String
765*9356374aSAndroid Build Coastguard Worker //   [FormatDuration] returns a string representing the duration in the
766*9356374aSAndroid Build Coastguard Worker //   form "72h3m0.5s". Leading zero units are omitted.  As a special
767*9356374aSAndroid Build Coastguard Worker //   case, durations less than one second format use a smaller unit
768*9356374aSAndroid Build Coastguard Worker //   (milli-, micro-, or nanoseconds) to ensure that the leading digit
769*9356374aSAndroid Build Coastguard Worker //   is non-zero.
770*9356374aSAndroid Build Coastguard Worker // Unlike Go, we format the zero duration as 0, with no unit.
FormatDuration(Duration d)771*9356374aSAndroid Build Coastguard Worker std::string FormatDuration(Duration d) {
772*9356374aSAndroid Build Coastguard Worker   constexpr Duration kMinDuration = Seconds(kint64min);
773*9356374aSAndroid Build Coastguard Worker   std::string s;
774*9356374aSAndroid Build Coastguard Worker   if (d == kMinDuration) {
775*9356374aSAndroid Build Coastguard Worker     // Avoid needing to negate kint64min by directly returning what the
776*9356374aSAndroid Build Coastguard Worker     // following code should produce in that case.
777*9356374aSAndroid Build Coastguard Worker     s = "-2562047788015215h30m8s";
778*9356374aSAndroid Build Coastguard Worker     return s;
779*9356374aSAndroid Build Coastguard Worker   }
780*9356374aSAndroid Build Coastguard Worker   if (d < ZeroDuration()) {
781*9356374aSAndroid Build Coastguard Worker     s.append("-");
782*9356374aSAndroid Build Coastguard Worker     d = -d;
783*9356374aSAndroid Build Coastguard Worker   }
784*9356374aSAndroid Build Coastguard Worker   if (d == InfiniteDuration()) {
785*9356374aSAndroid Build Coastguard Worker     s.append("inf");
786*9356374aSAndroid Build Coastguard Worker   } else if (d < Seconds(1)) {
787*9356374aSAndroid Build Coastguard Worker     // Special case for durations with a magnitude < 1 second.  The duration
788*9356374aSAndroid Build Coastguard Worker     // is printed as a fraction of a single unit, e.g., "1.2ms".
789*9356374aSAndroid Build Coastguard Worker     if (d < Microseconds(1)) {
790*9356374aSAndroid Build Coastguard Worker       AppendNumberUnit(&s, FDivDuration(d, Nanoseconds(1)), kDisplayNano);
791*9356374aSAndroid Build Coastguard Worker     } else if (d < Milliseconds(1)) {
792*9356374aSAndroid Build Coastguard Worker       AppendNumberUnit(&s, FDivDuration(d, Microseconds(1)), kDisplayMicro);
793*9356374aSAndroid Build Coastguard Worker     } else {
794*9356374aSAndroid Build Coastguard Worker       AppendNumberUnit(&s, FDivDuration(d, Milliseconds(1)), kDisplayMilli);
795*9356374aSAndroid Build Coastguard Worker     }
796*9356374aSAndroid Build Coastguard Worker   } else {
797*9356374aSAndroid Build Coastguard Worker     AppendNumberUnit(&s, IDivDuration(d, Hours(1), &d), kDisplayHour);
798*9356374aSAndroid Build Coastguard Worker     AppendNumberUnit(&s, IDivDuration(d, Minutes(1), &d), kDisplayMin);
799*9356374aSAndroid Build Coastguard Worker     AppendNumberUnit(&s, FDivDuration(d, Seconds(1)), kDisplaySec);
800*9356374aSAndroid Build Coastguard Worker   }
801*9356374aSAndroid Build Coastguard Worker   if (s.empty() || s == "-") {
802*9356374aSAndroid Build Coastguard Worker     s = "0";
803*9356374aSAndroid Build Coastguard Worker   }
804*9356374aSAndroid Build Coastguard Worker   return s;
805*9356374aSAndroid Build Coastguard Worker }
806*9356374aSAndroid Build Coastguard Worker 
807*9356374aSAndroid Build Coastguard Worker namespace {
808*9356374aSAndroid Build Coastguard Worker 
809*9356374aSAndroid Build Coastguard Worker // A helper for ParseDuration() that parses a leading number from the given
810*9356374aSAndroid Build Coastguard Worker // string and stores the result in *int_part/*frac_part/*frac_scale.  The
811*9356374aSAndroid Build Coastguard Worker // given string pointer is modified to point to the first unconsumed char.
ConsumeDurationNumber(const char ** dpp,const char * ep,int64_t * int_part,int64_t * frac_part,int64_t * frac_scale)812*9356374aSAndroid Build Coastguard Worker bool ConsumeDurationNumber(const char** dpp, const char* ep, int64_t* int_part,
813*9356374aSAndroid Build Coastguard Worker                            int64_t* frac_part, int64_t* frac_scale) {
814*9356374aSAndroid Build Coastguard Worker   *int_part = 0;
815*9356374aSAndroid Build Coastguard Worker   *frac_part = 0;
816*9356374aSAndroid Build Coastguard Worker   *frac_scale = 1;  // invariant: *frac_part < *frac_scale
817*9356374aSAndroid Build Coastguard Worker   const char* start = *dpp;
818*9356374aSAndroid Build Coastguard Worker   for (; *dpp != ep; *dpp += 1) {
819*9356374aSAndroid Build Coastguard Worker     const int d = **dpp - '0';  // contiguous digits
820*9356374aSAndroid Build Coastguard Worker     if (d < 0 || 10 <= d) break;
821*9356374aSAndroid Build Coastguard Worker 
822*9356374aSAndroid Build Coastguard Worker     if (*int_part > kint64max / 10) return false;
823*9356374aSAndroid Build Coastguard Worker     *int_part *= 10;
824*9356374aSAndroid Build Coastguard Worker     if (*int_part > kint64max - d) return false;
825*9356374aSAndroid Build Coastguard Worker     *int_part += d;
826*9356374aSAndroid Build Coastguard Worker   }
827*9356374aSAndroid Build Coastguard Worker   const bool int_part_empty = (*dpp == start);
828*9356374aSAndroid Build Coastguard Worker   if (*dpp == ep || **dpp != '.') return !int_part_empty;
829*9356374aSAndroid Build Coastguard Worker 
830*9356374aSAndroid Build Coastguard Worker   for (*dpp += 1; *dpp != ep; *dpp += 1) {
831*9356374aSAndroid Build Coastguard Worker     const int d = **dpp - '0';  // contiguous digits
832*9356374aSAndroid Build Coastguard Worker     if (d < 0 || 10 <= d) break;
833*9356374aSAndroid Build Coastguard Worker     if (*frac_scale <= kint64max / 10) {
834*9356374aSAndroid Build Coastguard Worker       *frac_part *= 10;
835*9356374aSAndroid Build Coastguard Worker       *frac_part += d;
836*9356374aSAndroid Build Coastguard Worker       *frac_scale *= 10;
837*9356374aSAndroid Build Coastguard Worker     }
838*9356374aSAndroid Build Coastguard Worker   }
839*9356374aSAndroid Build Coastguard Worker   return !int_part_empty || *frac_scale != 1;
840*9356374aSAndroid Build Coastguard Worker }
841*9356374aSAndroid Build Coastguard Worker 
842*9356374aSAndroid Build Coastguard Worker // A helper for ParseDuration() that parses a leading unit designator (e.g.,
843*9356374aSAndroid Build Coastguard Worker // ns, us, ms, s, m, h) from the given string and stores the resulting unit
844*9356374aSAndroid Build Coastguard Worker // in "*unit".  The given string pointer is modified to point to the first
845*9356374aSAndroid Build Coastguard Worker // unconsumed char.
ConsumeDurationUnit(const char ** start,const char * end,Duration * unit)846*9356374aSAndroid Build Coastguard Worker bool ConsumeDurationUnit(const char** start, const char* end, Duration* unit) {
847*9356374aSAndroid Build Coastguard Worker   size_t size = static_cast<size_t>(end - *start);
848*9356374aSAndroid Build Coastguard Worker   switch (size) {
849*9356374aSAndroid Build Coastguard Worker     case 0:
850*9356374aSAndroid Build Coastguard Worker       return false;
851*9356374aSAndroid Build Coastguard Worker     default:
852*9356374aSAndroid Build Coastguard Worker       switch (**start) {
853*9356374aSAndroid Build Coastguard Worker         case 'n':
854*9356374aSAndroid Build Coastguard Worker           if (*(*start + 1) == 's') {
855*9356374aSAndroid Build Coastguard Worker             *start += 2;
856*9356374aSAndroid Build Coastguard Worker             *unit = Nanoseconds(1);
857*9356374aSAndroid Build Coastguard Worker             return true;
858*9356374aSAndroid Build Coastguard Worker           }
859*9356374aSAndroid Build Coastguard Worker           break;
860*9356374aSAndroid Build Coastguard Worker         case 'u':
861*9356374aSAndroid Build Coastguard Worker           if (*(*start + 1) == 's') {
862*9356374aSAndroid Build Coastguard Worker             *start += 2;
863*9356374aSAndroid Build Coastguard Worker             *unit = Microseconds(1);
864*9356374aSAndroid Build Coastguard Worker             return true;
865*9356374aSAndroid Build Coastguard Worker           }
866*9356374aSAndroid Build Coastguard Worker           break;
867*9356374aSAndroid Build Coastguard Worker         case 'm':
868*9356374aSAndroid Build Coastguard Worker           if (*(*start + 1) == 's') {
869*9356374aSAndroid Build Coastguard Worker             *start += 2;
870*9356374aSAndroid Build Coastguard Worker             *unit = Milliseconds(1);
871*9356374aSAndroid Build Coastguard Worker             return true;
872*9356374aSAndroid Build Coastguard Worker           }
873*9356374aSAndroid Build Coastguard Worker           break;
874*9356374aSAndroid Build Coastguard Worker         default:
875*9356374aSAndroid Build Coastguard Worker           break;
876*9356374aSAndroid Build Coastguard Worker       }
877*9356374aSAndroid Build Coastguard Worker       ABSL_FALLTHROUGH_INTENDED;
878*9356374aSAndroid Build Coastguard Worker     case 1:
879*9356374aSAndroid Build Coastguard Worker       switch (**start) {
880*9356374aSAndroid Build Coastguard Worker         case 's':
881*9356374aSAndroid Build Coastguard Worker           *unit = Seconds(1);
882*9356374aSAndroid Build Coastguard Worker           *start += 1;
883*9356374aSAndroid Build Coastguard Worker           return true;
884*9356374aSAndroid Build Coastguard Worker         case 'm':
885*9356374aSAndroid Build Coastguard Worker           *unit = Minutes(1);
886*9356374aSAndroid Build Coastguard Worker           *start += 1;
887*9356374aSAndroid Build Coastguard Worker           return true;
888*9356374aSAndroid Build Coastguard Worker         case 'h':
889*9356374aSAndroid Build Coastguard Worker           *unit = Hours(1);
890*9356374aSAndroid Build Coastguard Worker           *start += 1;
891*9356374aSAndroid Build Coastguard Worker           return true;
892*9356374aSAndroid Build Coastguard Worker         default:
893*9356374aSAndroid Build Coastguard Worker           return false;
894*9356374aSAndroid Build Coastguard Worker       }
895*9356374aSAndroid Build Coastguard Worker   }
896*9356374aSAndroid Build Coastguard Worker }
897*9356374aSAndroid Build Coastguard Worker 
898*9356374aSAndroid Build Coastguard Worker }  // namespace
899*9356374aSAndroid Build Coastguard Worker 
900*9356374aSAndroid Build Coastguard Worker // From Go's doc at https://golang.org/pkg/time/#ParseDuration
901*9356374aSAndroid Build Coastguard Worker //   [ParseDuration] parses a duration string. A duration string is
902*9356374aSAndroid Build Coastguard Worker //   a possibly signed sequence of decimal numbers, each with optional
903*9356374aSAndroid Build Coastguard Worker //   fraction and a unit suffix, such as "300ms", "-1.5h" or "2h45m".
904*9356374aSAndroid Build Coastguard Worker //   Valid time units are "ns", "us" "ms", "s", "m", "h".
ParseDuration(absl::string_view dur_sv,Duration * d)905*9356374aSAndroid Build Coastguard Worker bool ParseDuration(absl::string_view dur_sv, Duration* d) {
906*9356374aSAndroid Build Coastguard Worker   int sign = 1;
907*9356374aSAndroid Build Coastguard Worker   if (absl::ConsumePrefix(&dur_sv, "-")) {
908*9356374aSAndroid Build Coastguard Worker     sign = -1;
909*9356374aSAndroid Build Coastguard Worker   } else {
910*9356374aSAndroid Build Coastguard Worker     absl::ConsumePrefix(&dur_sv, "+");
911*9356374aSAndroid Build Coastguard Worker   }
912*9356374aSAndroid Build Coastguard Worker   if (dur_sv.empty()) return false;
913*9356374aSAndroid Build Coastguard Worker 
914*9356374aSAndroid Build Coastguard Worker   // Special case for a string of "0".
915*9356374aSAndroid Build Coastguard Worker   if (dur_sv == "0") {
916*9356374aSAndroid Build Coastguard Worker     *d = ZeroDuration();
917*9356374aSAndroid Build Coastguard Worker     return true;
918*9356374aSAndroid Build Coastguard Worker   }
919*9356374aSAndroid Build Coastguard Worker 
920*9356374aSAndroid Build Coastguard Worker   if (dur_sv == "inf") {
921*9356374aSAndroid Build Coastguard Worker     *d = sign * InfiniteDuration();
922*9356374aSAndroid Build Coastguard Worker     return true;
923*9356374aSAndroid Build Coastguard Worker   }
924*9356374aSAndroid Build Coastguard Worker 
925*9356374aSAndroid Build Coastguard Worker   const char* start = dur_sv.data();
926*9356374aSAndroid Build Coastguard Worker   const char* end = start + dur_sv.size();
927*9356374aSAndroid Build Coastguard Worker 
928*9356374aSAndroid Build Coastguard Worker   Duration dur;
929*9356374aSAndroid Build Coastguard Worker   while (start != end) {
930*9356374aSAndroid Build Coastguard Worker     int64_t int_part;
931*9356374aSAndroid Build Coastguard Worker     int64_t frac_part;
932*9356374aSAndroid Build Coastguard Worker     int64_t frac_scale;
933*9356374aSAndroid Build Coastguard Worker     Duration unit;
934*9356374aSAndroid Build Coastguard Worker     if (!ConsumeDurationNumber(&start, end, &int_part, &frac_part,
935*9356374aSAndroid Build Coastguard Worker                                &frac_scale) ||
936*9356374aSAndroid Build Coastguard Worker         !ConsumeDurationUnit(&start, end, &unit)) {
937*9356374aSAndroid Build Coastguard Worker       return false;
938*9356374aSAndroid Build Coastguard Worker     }
939*9356374aSAndroid Build Coastguard Worker     if (int_part != 0) dur += sign * int_part * unit;
940*9356374aSAndroid Build Coastguard Worker     if (frac_part != 0) dur += sign * frac_part * unit / frac_scale;
941*9356374aSAndroid Build Coastguard Worker   }
942*9356374aSAndroid Build Coastguard Worker   *d = dur;
943*9356374aSAndroid Build Coastguard Worker   return true;
944*9356374aSAndroid Build Coastguard Worker }
945*9356374aSAndroid Build Coastguard Worker 
AbslParseFlag(absl::string_view text,Duration * dst,std::string *)946*9356374aSAndroid Build Coastguard Worker bool AbslParseFlag(absl::string_view text, Duration* dst, std::string*) {
947*9356374aSAndroid Build Coastguard Worker   return ParseDuration(text, dst);
948*9356374aSAndroid Build Coastguard Worker }
949*9356374aSAndroid Build Coastguard Worker 
AbslUnparseFlag(Duration d)950*9356374aSAndroid Build Coastguard Worker std::string AbslUnparseFlag(Duration d) { return FormatDuration(d); }
ParseFlag(const std::string & text,Duration * dst,std::string *)951*9356374aSAndroid Build Coastguard Worker bool ParseFlag(const std::string& text, Duration* dst, std::string* ) {
952*9356374aSAndroid Build Coastguard Worker   return ParseDuration(text, dst);
953*9356374aSAndroid Build Coastguard Worker }
954*9356374aSAndroid Build Coastguard Worker 
UnparseFlag(Duration d)955*9356374aSAndroid Build Coastguard Worker std::string UnparseFlag(Duration d) { return FormatDuration(d); }
956*9356374aSAndroid Build Coastguard Worker 
957*9356374aSAndroid Build Coastguard Worker ABSL_NAMESPACE_END
958*9356374aSAndroid Build Coastguard Worker }  // namespace absl
959