Example #1
0
func (q *AliveHookQueue) loop(initial *State) {
	defer q.tomb.Done()
	defer watcher.Stop(q.w, &q.tomb)

	// Consume initial event, and reconcile with initial state, by inserting
	// a new RelationUnitsChange before the initial event, which schedules
	// every missing unit for immediate departure before anything else happens
	// (apart from a single potential required post-joined changed event).
	ch1, ok := <-q.w.Changes()
	if !ok {
		q.tomb.Kill(watcher.MustErr(q.w))
		return
	}
	if len(ch1.Departed) != 0 {
		panic("AliveHookQueue must be started with a fresh RelationUnitsWatcher")
	}
	q.changedPending = initial.ChangedPending
	ch0 := state.RelationUnitsChange{}
	for unit, version := range initial.Members {
		q.info[unit] = &unitInfo{
			unit:    unit,
			version: version,
			joined:  true,
		}
		if _, found := ch1.Changed[unit]; !found {
			ch0.Departed = append(ch0.Departed, unit)
		}
	}
	q.update(ch0)
	q.update(ch1)

	var next hook.Info
	var out chan<- hook.Info
	for {
		if q.empty() {
			out = nil
		} else {
			out = q.out
			next = q.next()
		}
		select {
		case <-q.tomb.Dying():
			return
		case ch, ok := <-q.w.Changes():
			if !ok {
				q.tomb.Kill(watcher.MustErr(q.w))
				return
			}
			q.update(ch)
		case out <- next:
			q.pop()
		}
	}
}
func (d send) check(c *C, in chan state.RelationUnitsChange, out chan hook.Info) {
	ruc := state.RelationUnitsChange{Changed: map[string]state.UnitSettings{}}
	for name, version := range d.changed {
		ruc.Changed[name] = state.UnitSettings{
			Version:  version,
			Settings: settings(name, version),
		}
	}
	for _, name := range d.departed {
		ruc.Departed = append(ruc.Departed, name)
	}
	in <- ruc
}