66 lines
1.4 KiB
Go
66 lines
1.4 KiB
Go
package jitter
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import (
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"time"
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"go.unistack.org/micro/v3/util/rand"
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)
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// Ticker is similar to time.Ticker but ticks at random intervals between
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// the min and max duration values (stored internally as int64 nanosecond
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// counts).
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type Ticker struct {
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C chan time.Time
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done chan chan struct{}
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min int64
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max int64
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rng rand.Rand
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}
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// NewTicker returns a pointer to an initialized instance of the Ticker.
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// Min and max are durations of the shortest and longest allowed
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// ticks. Ticker will run in a goroutine until explicitly stopped.
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func NewTicker(min, max time.Duration) *Ticker {
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ticker := &Ticker{
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C: make(chan time.Time),
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done: make(chan chan struct{}),
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min: min.Nanoseconds(),
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max: max.Nanoseconds(),
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}
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go ticker.run()
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return ticker
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}
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// Stop terminates the ticker goroutine and closes the C channel.
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func (ticker *Ticker) Stop() {
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c := make(chan struct{})
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ticker.done <- c
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<-c
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}
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func (ticker *Ticker) run() {
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defer close(ticker.C)
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t := time.NewTimer(ticker.nextInterval())
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for {
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// either a stop signal or a timeout
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select {
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case c := <-ticker.done:
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t.Stop()
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close(c)
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return
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case <-t.C:
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select {
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case ticker.C <- time.Now():
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t.Stop()
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t = time.NewTimer(ticker.nextInterval())
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default:
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// there could be noone receiving...
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}
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}
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}
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}
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func (ticker *Ticker) nextInterval() time.Duration {
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return time.Duration(ticker.rng.Int63n(ticker.max-ticker.min)+ticker.min) * time.Nanosecond
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}
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