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// SPDX-License-Identifier: GPL-3.0-or-later
package ticker
import "time"
type (
// Ticker holds a channel that delivers ticks of a clock at intervals.
// The ticks are aligned to interval boundaries.
Ticker struct {
C <-chan int
done chan struct{}
loops int
interval time.Duration
}
)
// New returns a new Ticker containing a channel that will send the time with a period specified by the duration argument.
// It adjusts the intervals or drops ticks to make up for slow receivers.
// The duration must be greater than zero; if not, New will panic. Stop the Ticker to release associated resources.
func New(interval time.Duration) *Ticker {
ticker := &Ticker{
interval: interval,
done: make(chan struct{}, 1),
}
ticker.start()
return ticker
}
func (t *Ticker) start() {
ch := make(chan int)
t.C = ch
go func() {
LOOP:
for {
now := time.Now()
nextRun := now.Truncate(t.interval).Add(t.interval)
time.Sleep(nextRun.Sub(now))
select {
case <-t.done:
close(ch)
break LOOP
case ch <- t.loops:
t.loops++
}
}
}()
}
// Stop turns off a Ticker. After Stop, no more ticks will be sent.
// Stop does not close the channel, to prevent a read from the channel succeeding incorrectly.
func (t *Ticker) Stop() {
t.done <- struct{}{}
}
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