diff options
Diffstat (limited to 'vendor/golang.org/x/time')
| -rw-r--r-- | vendor/golang.org/x/time/AUTHORS | 3 | ||||
| -rw-r--r-- | vendor/golang.org/x/time/CONTRIBUTORS | 3 | ||||
| -rw-r--r-- | vendor/golang.org/x/time/rate/rate.go | 154 | ||||
| -rw-r--r-- | vendor/golang.org/x/time/rate/sometimes.go | 67 |
4 files changed, 159 insertions, 68 deletions
diff --git a/vendor/golang.org/x/time/AUTHORS b/vendor/golang.org/x/time/AUTHORS deleted file mode 100644 index 15167cd7..00000000 --- a/vendor/golang.org/x/time/AUTHORS +++ /dev/null @@ -1,3 +0,0 @@ -# This source code refers to The Go Authors for copyright purposes. -# The master list of authors is in the main Go distribution, -# visible at http://tip.golang.org/AUTHORS. diff --git a/vendor/golang.org/x/time/CONTRIBUTORS b/vendor/golang.org/x/time/CONTRIBUTORS deleted file mode 100644 index 1c4577e9..00000000 --- a/vendor/golang.org/x/time/CONTRIBUTORS +++ /dev/null @@ -1,3 +0,0 @@ -# This source code was written by the Go contributors. -# The master list of contributors is in the main Go distribution, -# visible at http://tip.golang.org/CONTRIBUTORS. diff --git a/vendor/golang.org/x/time/rate/rate.go b/vendor/golang.org/x/time/rate/rate.go index a98fe778..8f7c29f1 100644 --- a/vendor/golang.org/x/time/rate/rate.go +++ b/vendor/golang.org/x/time/rate/rate.go @@ -80,6 +80,19 @@ func (lim *Limiter) Burst() int { return lim.burst } +// TokensAt returns the number of tokens available at time t. +func (lim *Limiter) TokensAt(t time.Time) float64 { + lim.mu.Lock() + _, _, tokens := lim.advance(t) // does not mutute lim + lim.mu.Unlock() + return tokens +} + +// Tokens returns the number of tokens available now. +func (lim *Limiter) Tokens() float64 { + return lim.TokensAt(time.Now()) +} + // NewLimiter returns a new Limiter that allows events up to rate r and permits // bursts of at most b tokens. func NewLimiter(r Limit, b int) *Limiter { @@ -89,16 +102,16 @@ func NewLimiter(r Limit, b int) *Limiter { } } -// Allow is shorthand for AllowN(time.Now(), 1). +// Allow reports whether an event may happen now. func (lim *Limiter) Allow() bool { return lim.AllowN(time.Now(), 1) } -// AllowN reports whether n events may happen at time now. +// AllowN reports whether n events may happen at time t. // Use this method if you intend to drop / skip events that exceed the rate limit. // Otherwise use Reserve or Wait. -func (lim *Limiter) AllowN(now time.Time, n int) bool { - return lim.reserveN(now, n, 0).ok +func (lim *Limiter) AllowN(t time.Time, n int) bool { + return lim.reserveN(t, n, 0).ok } // A Reservation holds information about events that are permitted by a Limiter to happen after a delay. @@ -125,17 +138,17 @@ func (r *Reservation) Delay() time.Duration { } // InfDuration is the duration returned by Delay when a Reservation is not OK. -const InfDuration = time.Duration(1<<63 - 1) +const InfDuration = time.Duration(math.MaxInt64) // DelayFrom returns the duration for which the reservation holder must wait // before taking the reserved action. Zero duration means act immediately. // InfDuration means the limiter cannot grant the tokens requested in this // Reservation within the maximum wait time. -func (r *Reservation) DelayFrom(now time.Time) time.Duration { +func (r *Reservation) DelayFrom(t time.Time) time.Duration { if !r.ok { return InfDuration } - delay := r.timeToAct.Sub(now) + delay := r.timeToAct.Sub(t) if delay < 0 { return 0 } @@ -145,13 +158,12 @@ func (r *Reservation) DelayFrom(now time.Time) time.Duration { // Cancel is shorthand for CancelAt(time.Now()). func (r *Reservation) Cancel() { r.CancelAt(time.Now()) - return } // CancelAt indicates that the reservation holder will not perform the reserved action // and reverses the effects of this Reservation on the rate limit as much as possible, // considering that other reservations may have already been made. -func (r *Reservation) CancelAt(now time.Time) { +func (r *Reservation) CancelAt(t time.Time) { if !r.ok { return } @@ -159,7 +171,7 @@ func (r *Reservation) CancelAt(now time.Time) { r.lim.mu.Lock() defer r.lim.mu.Unlock() - if r.lim.limit == Inf || r.tokens == 0 || r.timeToAct.Before(now) { + if r.lim.limit == Inf || r.tokens == 0 || r.timeToAct.Before(t) { return } @@ -171,23 +183,21 @@ func (r *Reservation) CancelAt(now time.Time) { return } // advance time to now - now, _, tokens := r.lim.advance(now) + t, _, tokens := r.lim.advance(t) // calculate new number of tokens tokens += restoreTokens if burst := float64(r.lim.burst); tokens > burst { tokens = burst } // update state - r.lim.last = now + r.lim.last = t r.lim.tokens = tokens if r.timeToAct == r.lim.lastEvent { prevEvent := r.timeToAct.Add(r.limit.durationFromTokens(float64(-r.tokens))) - if !prevEvent.Before(now) { + if !prevEvent.Before(t) { r.lim.lastEvent = prevEvent } } - - return } // Reserve is shorthand for ReserveN(time.Now(), 1). @@ -199,18 +209,20 @@ func (lim *Limiter) Reserve() *Reservation { // The Limiter takes this Reservation into account when allowing future events. // The returned Reservation’s OK() method returns false if n exceeds the Limiter's burst size. // Usage example: -// r := lim.ReserveN(time.Now(), 1) -// if !r.OK() { -// // Not allowed to act! Did you remember to set lim.burst to be > 0 ? -// return -// } -// time.Sleep(r.Delay()) -// Act() +// +// r := lim.ReserveN(time.Now(), 1) +// if !r.OK() { +// // Not allowed to act! Did you remember to set lim.burst to be > 0 ? +// return +// } +// time.Sleep(r.Delay()) +// Act() +// // Use this method if you wish to wait and slow down in accordance with the rate limit without dropping events. // If you need to respect a deadline or cancel the delay, use Wait instead. // To drop or skip events exceeding rate limit, use Allow instead. -func (lim *Limiter) ReserveN(now time.Time, n int) *Reservation { - r := lim.reserveN(now, n, InfDuration) +func (lim *Limiter) ReserveN(t time.Time, n int) *Reservation { + r := lim.reserveN(t, n, InfDuration) return &r } @@ -224,6 +236,18 @@ func (lim *Limiter) Wait(ctx context.Context) (err error) { // canceled, or the expected wait time exceeds the Context's Deadline. // The burst limit is ignored if the rate limit is Inf. func (lim *Limiter) WaitN(ctx context.Context, n int) (err error) { + // The test code calls lim.wait with a fake timer generator. + // This is the real timer generator. + newTimer := func(d time.Duration) (<-chan time.Time, func() bool, func()) { + timer := time.NewTimer(d) + return timer.C, timer.Stop, func() {} + } + + return lim.wait(ctx, n, time.Now(), newTimer) +} + +// wait is the internal implementation of WaitN. +func (lim *Limiter) wait(ctx context.Context, n int, t time.Time, newTimer func(d time.Duration) (<-chan time.Time, func() bool, func())) error { lim.mu.Lock() burst := lim.burst limit := lim.limit @@ -239,25 +263,25 @@ func (lim *Limiter) WaitN(ctx context.Context, n int) (err error) { default: } // Determine wait limit - now := time.Now() waitLimit := InfDuration if deadline, ok := ctx.Deadline(); ok { - waitLimit = deadline.Sub(now) + waitLimit = deadline.Sub(t) } // Reserve - r := lim.reserveN(now, n, waitLimit) + r := lim.reserveN(t, n, waitLimit) if !r.ok { return fmt.Errorf("rate: Wait(n=%d) would exceed context deadline", n) } // Wait if necessary - delay := r.DelayFrom(now) + delay := r.DelayFrom(t) if delay == 0 { return nil } - t := time.NewTimer(delay) - defer t.Stop() + ch, stop, advance := newTimer(delay) + defer stop() + advance() // only has an effect when testing select { - case <-t.C: + case <-ch: // We can proceed. return nil case <-ctx.Done(): @@ -276,13 +300,13 @@ func (lim *Limiter) SetLimit(newLimit Limit) { // SetLimitAt sets a new Limit for the limiter. The new Limit, and Burst, may be violated // or underutilized by those which reserved (using Reserve or Wait) but did not yet act // before SetLimitAt was called. -func (lim *Limiter) SetLimitAt(now time.Time, newLimit Limit) { +func (lim *Limiter) SetLimitAt(t time.Time, newLimit Limit) { lim.mu.Lock() defer lim.mu.Unlock() - now, _, tokens := lim.advance(now) + t, _, tokens := lim.advance(t) - lim.last = now + lim.last = t lim.tokens = tokens lim.limit = newLimit } @@ -293,13 +317,13 @@ func (lim *Limiter) SetBurst(newBurst int) { } // SetBurstAt sets a new burst size for the limiter. -func (lim *Limiter) SetBurstAt(now time.Time, newBurst int) { +func (lim *Limiter) SetBurstAt(t time.Time, newBurst int) { lim.mu.Lock() defer lim.mu.Unlock() - now, _, tokens := lim.advance(now) + t, _, tokens := lim.advance(t) - lim.last = now + lim.last = t lim.tokens = tokens lim.burst = newBurst } @@ -307,20 +331,32 @@ func (lim *Limiter) SetBurstAt(now time.Time, newBurst int) { // reserveN is a helper method for AllowN, ReserveN, and WaitN. // maxFutureReserve specifies the maximum reservation wait duration allowed. // reserveN returns Reservation, not *Reservation, to avoid allocation in AllowN and WaitN. -func (lim *Limiter) reserveN(now time.Time, n int, maxFutureReserve time.Duration) Reservation { +func (lim *Limiter) reserveN(t time.Time, n int, maxFutureReserve time.Duration) Reservation { lim.mu.Lock() + defer lim.mu.Unlock() if lim.limit == Inf { - lim.mu.Unlock() return Reservation{ ok: true, lim: lim, tokens: n, - timeToAct: now, + timeToAct: t, + } + } else if lim.limit == 0 { + var ok bool + if lim.burst >= n { + ok = true + lim.burst -= n + } + return Reservation{ + ok: ok, + lim: lim, + tokens: lim.burst, + timeToAct: t, } } - now, last, tokens := lim.advance(now) + t, last, tokens := lim.advance(t) // Calculate the remaining number of tokens resulting from the request. tokens -= float64(n) @@ -342,61 +378,55 @@ func (lim *Limiter) reserveN(now time.Time, n int, maxFutureReserve time.Duratio } if ok { r.tokens = n - r.timeToAct = now.Add(waitDuration) + r.timeToAct = t.Add(waitDuration) } // Update state if ok { - lim.last = now + lim.last = t lim.tokens = tokens lim.lastEvent = r.timeToAct } else { lim.last = last } - lim.mu.Unlock() return r } // advance calculates and returns an updated state for lim resulting from the passage of time. // lim is not changed. // advance requires that lim.mu is held. -func (lim *Limiter) advance(now time.Time) (newNow time.Time, newLast time.Time, newTokens float64) { +func (lim *Limiter) advance(t time.Time) (newT time.Time, newLast time.Time, newTokens float64) { last := lim.last - if now.Before(last) { - last = now - } - - // Avoid making delta overflow below when last is very old. - maxElapsed := lim.limit.durationFromTokens(float64(lim.burst) - lim.tokens) - elapsed := now.Sub(last) - if elapsed > maxElapsed { - elapsed = maxElapsed + if t.Before(last) { + last = t } // Calculate the new number of tokens, due to time that passed. + elapsed := t.Sub(last) delta := lim.limit.tokensFromDuration(elapsed) tokens := lim.tokens + delta if burst := float64(lim.burst); tokens > burst { tokens = burst } - - return now, last, tokens + return t, last, tokens } // durationFromTokens is a unit conversion function from the number of tokens to the duration // of time it takes to accumulate them at a rate of limit tokens per second. func (limit Limit) durationFromTokens(tokens float64) time.Duration { + if limit <= 0 { + return InfDuration + } seconds := tokens / float64(limit) - return time.Nanosecond * time.Duration(1e9*seconds) + return time.Duration(float64(time.Second) * seconds) } // tokensFromDuration is a unit conversion function from a time duration to the number of tokens // which could be accumulated during that duration at a rate of limit tokens per second. func (limit Limit) tokensFromDuration(d time.Duration) float64 { - // Split the integer and fractional parts ourself to minimize rounding errors. - // See golang.org/issues/34861. - sec := float64(d/time.Second) * float64(limit) - nsec := float64(d%time.Second) * float64(limit) - return sec + nsec/1e9 + if limit <= 0 { + return 0 + } + return d.Seconds() * float64(limit) } diff --git a/vendor/golang.org/x/time/rate/sometimes.go b/vendor/golang.org/x/time/rate/sometimes.go new file mode 100644 index 00000000..6ba99ddb --- /dev/null +++ b/vendor/golang.org/x/time/rate/sometimes.go @@ -0,0 +1,67 @@ +// Copyright 2022 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package rate + +import ( + "sync" + "time" +) + +// Sometimes will perform an action occasionally. The First, Every, and +// Interval fields govern the behavior of Do, which performs the action. +// A zero Sometimes value will perform an action exactly once. +// +// # Example: logging with rate limiting +// +// var sometimes = rate.Sometimes{First: 3, Interval: 10*time.Second} +// func Spammy() { +// sometimes.Do(func() { log.Info("here I am!") }) +// } +type Sometimes struct { + First int // if non-zero, the first N calls to Do will run f. + Every int // if non-zero, every Nth call to Do will run f. + Interval time.Duration // if non-zero and Interval has elapsed since f's last run, Do will run f. + + mu sync.Mutex + count int // number of Do calls + last time.Time // last time f was run +} + +// Do runs the function f as allowed by First, Every, and Interval. +// +// The model is a union (not intersection) of filters. The first call to Do +// always runs f. Subsequent calls to Do run f if allowed by First or Every or +// Interval. +// +// A non-zero First:N causes the first N Do(f) calls to run f. +// +// A non-zero Every:M causes every Mth Do(f) call, starting with the first, to +// run f. +// +// A non-zero Interval causes Do(f) to run f if Interval has elapsed since +// Do last ran f. +// +// Specifying multiple filters produces the union of these execution streams. +// For example, specifying both First:N and Every:M causes the first N Do(f) +// calls and every Mth Do(f) call, starting with the first, to run f. See +// Examples for more. +// +// If Do is called multiple times simultaneously, the calls will block and run +// serially. Therefore, Do is intended for lightweight operations. +// +// Because a call to Do may block until f returns, if f causes Do to be called, +// it will deadlock. +func (s *Sometimes) Do(f func()) { + s.mu.Lock() + defer s.mu.Unlock() + if s.count == 0 || + (s.First > 0 && s.count < s.First) || + (s.Every > 0 && s.count%s.Every == 0) || + (s.Interval > 0 && time.Since(s.last) >= s.Interval) { + f() + s.last = time.Now() + } + s.count++ +} |