.gitignore added

[dotfiles/.git] / .config / coc / extensions / coc-go-data / tools / pkg / mod / golang.org / x / tools@v0.1.1-0.20210319172145-bda8f5cee399 / godoc / util / throttle.go

diff --git a/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.1-0.20210319172145-bda8f5cee399/godoc/util/throttle.go b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.1-0.20210319172145-bda8f5cee399/godoc/util/throttle.go
new file mode 100644 (file)
index 0000000..53d9ba6
--- /dev/null
+++ b/.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.1.1-0.20210319172145-bda8f5cee399/godoc/util/throttle.go
@@ -0,0 +1,88 @@
+// Copyright 2011 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 util
+
+import "time"
+
+// A Throttle permits throttling of a goroutine by
+// calling the Throttle method repeatedly.
+//
+type Throttle struct {
+       f  float64       // f = (1-r)/r for 0 < r < 1
+       dt time.Duration // minimum run time slice; >= 0
+       tr time.Duration // accumulated time running
+       ts time.Duration // accumulated time stopped
+       tt time.Time     // earliest throttle time (= time Throttle returned + tm)
+}
+
+// NewThrottle creates a new Throttle with a throttle value r and
+// a minimum allocated run time slice of dt:
+//
+//     r == 0: "empty" throttle; the goroutine is always sleeping
+//     r == 1: full throttle; the goroutine is never sleeping
+//
+// A value of r == 0.6 throttles a goroutine such that it runs
+// approx. 60% of the time, and sleeps approx. 40% of the time.
+// Values of r < 0 or r > 1 are clamped down to values between 0 and 1.
+// Values of dt < 0 are set to 0.
+//
+func NewThrottle(r float64, dt time.Duration) *Throttle {
+       var f float64
+       switch {
+       case r <= 0:
+               f = -1 // indicates always sleep
+       case r >= 1:
+               f = 0 // assume r == 1 (never sleep)
+       default:
+               // 0 < r < 1
+               f = (1 - r) / r
+       }
+       if dt < 0 {
+               dt = 0
+       }
+       return &Throttle{f: f, dt: dt, tt: time.Now().Add(dt)}
+}
+
+// Throttle calls time.Sleep such that over time the ratio tr/ts between
+// accumulated run (tr) and sleep times (ts) approximates the value 1/(1-r)
+// where r is the throttle value. Throttle returns immediately (w/o sleeping)
+// if less than tm ns have passed since the last call to Throttle.
+//
+func (p *Throttle) Throttle() {
+       if p.f < 0 {
+               select {} // always sleep
+       }
+
+       t0 := time.Now()
+       if t0.Before(p.tt) {
+               return // keep running (minimum time slice not exhausted yet)
+       }
+
+       // accumulate running time
+       p.tr += t0.Sub(p.tt) + p.dt
+
+       // compute sleep time
+       // Over time we want:
+       //
+       //      tr/ts = r/(1-r)
+       //
+       // Thus:
+       //
+       //      ts = tr*f with f = (1-r)/r
+       //
+       // After some incremental run time δr added to the total run time
+       // tr, the incremental sleep-time δs to get to the same ratio again
+       // after waking up from time.Sleep is:
+       if δs := time.Duration(float64(p.tr)*p.f) - p.ts; δs > 0 {
+               time.Sleep(δs)
+       }
+
+       // accumulate (actual) sleep time
+       t1 := time.Now()
+       p.ts += t1.Sub(t0)
+
+       // set earliest next throttle time
+       p.tt = t1.Add(p.dt)
+}