restic/internal/ui/progress/updater.go

85 lines
1.8 KiB
Go

package progress
import (
"time"
"github.com/restic/restic/internal/debug"
"github.com/restic/restic/internal/ui/signals"
)
// An UpdateFunc is a callback for a (progress) Updater.
//
// The final argument is true if Updater.Done has been called,
// which means that the current call will be the last.
type UpdateFunc func(runtime time.Duration, final bool)
// An Updater controls a goroutine that periodically calls an UpdateFunc.
//
// The UpdateFunc is also called when SIGUSR1 (or SIGINFO, on BSD) is received.
type Updater struct {
report UpdateFunc
start time.Time
stopped chan struct{} // Closed by run.
stop chan struct{} // Close to stop run.
tick *time.Ticker
}
// NewUpdater starts a new Updater.
func NewUpdater(interval time.Duration, report UpdateFunc) *Updater {
c := &Updater{
report: report,
start: time.Now(),
stopped: make(chan struct{}),
stop: make(chan struct{}),
}
if interval > 0 {
c.tick = time.NewTicker(interval)
}
go c.run()
return c
}
// Done tells an Updater to stop and waits for it to report its final value.
// Later calls do nothing.
func (c *Updater) Done() {
if c == nil || c.stop == nil {
return
}
if c.tick != nil {
c.tick.Stop()
}
close(c.stop)
<-c.stopped // Wait for last progress report.
c.stop = nil
}
func (c *Updater) run() {
defer close(c.stopped)
defer func() {
// Must be a func so that time.Since isn't called at defer time.
c.report(time.Since(c.start), true)
}()
var tick <-chan time.Time
if c.tick != nil {
tick = c.tick.C
}
signalsCh := signals.GetProgressChannel()
for {
var now time.Time
select {
case now = <-tick:
case sig := <-signalsCh:
debug.Log("Signal received: %v\n", sig)
now = time.Now()
case <-c.stop:
return
}
c.report(now.Sub(c.start), false)
}
}