// Subscribe returns an iterator over active alerts that have not been
// resolved and successfully notified about.
// They are not guaranteed to be in chronological order.
func (a *Alerts) Subscribe() provider.AlertIterator {
var (
ch = make(chan *types.Alert, 200)
done = make(chan struct{})
)
alerts, err := a.getPending()
a.mtx.Lock()
i := a.next
a.next++
a.listeners[i] = ch
a.mtx.Unlock()
go func() {
defer func() {
a.mtx.Lock()
delete(a.listeners, i)
close(ch)
a.mtx.Unlock()
}()
for _, a := range alerts {
select {
case ch <- a:
case <-done:
return
}
}
<-done
}()
return provider.NewAlertIterator(ch, done, err)
}
// GetPending returns an iterator over all alerts that have
// pending notifications.
func (a *Alerts) GetPending() provider.AlertIterator {
var (
ch = make(chan *types.Alert, 200)
done = make(chan struct{})
)
alerts, err := a.getPending()
go func() {
defer close(ch)
for _, a := range alerts {
select {
case ch <- a:
case <-done:
return
}
}
}()
return provider.NewAlertIterator(ch, done, err)
}