Golang Registry.Walk方法代碼示例

// A first-come-first-serve scheduler: acquires the first offer that can support the task
func FCFSScheduleFunc(r offers.Registry, unused SlaveIndex, task *podtask.T) (offers.Perishable, error) {
	podName := fmt.Sprintf("%s/%s", task.Pod.Namespace, task.Pod.Name)
	var acceptedOffer offers.Perishable
	err := r.Walk(func(p offers.Perishable) (bool, error) {
		offer := p.Details()
		if offer == nil {
			return false, fmt.Errorf("nil offer while scheduling task %v", task.ID)
		}
		if task.AcceptOffer(offer) {
			if p.Acquire() {
				acceptedOffer = p
				log.V(3).Infof("Pod %s accepted offer %v", podName, offer.Id.GetValue())
				return true, nil // stop, we found an offer
			}
		}
		return false, nil // continue
	})
	if acceptedOffer != nil {
		if err != nil {
			log.Warningf("problems walking the offer registry: %v, attempting to continue", err)
		}
		return acceptedOffer, nil
	}
	if err != nil {
		log.V(2).Infof("failed to find a fit for pod: %s, err = %v", podName, err)
		return nil, err
	}
	log.V(2).Infof("failed to find a fit for pod: %s", podName)
	return nil, noSuitableOffersErr
}

// A first-come-first-serve scheduler: acquires the first offer that can support the task
func (fps *fcfsPodScheduler) SchedulePod(r offers.Registry, task *podtask.T) (offers.Perishable, *podtask.Spec, error) {
	podName := fmt.Sprintf("%s/%s", task.Pod.Namespace, task.Pod.Name)
	var matchingOffer offers.Perishable
	var acceptedSpec *podtask.Spec
	err := r.Walk(func(p offers.Perishable) (bool, error) {
		offer := p.Details()
		if offer == nil {
			return false, fmt.Errorf("nil offer while scheduling task %v", task.ID)
		}

		// check that the node actually exists. As offers are declined if not, the
		// case n==nil can only happen when the node object was deleted since the
		// offer came in.
		nodeName := offer.GetHostname()
		n := fps.lookupNode(nodeName)
		if n == nil {
			log.V(3).Infof("ignoring offer for node %s because node went away", nodeName)
			return false, nil
		}

		ps := podtask.NewProcureState(offer)
		err := fps.procurement.Procure(task, n, ps)
		if err != nil {
			log.V(5).Infof(
				"Offer %q does not fit pod %s/%s: %v",
				offer.Id, task.Pod.Namespace, task.Pod.Name, err,
			)
			return false, nil // continue
		}

		if !p.Acquire() {
			log.V(2).Infof(
				"Could not acquire offer %q for pod %s/%s",
				offer.Id, task.Pod.Namespace, task.Pod.Name,
			)
			return false, nil // continue
		}

		matchingOffer = p
		acceptedSpec, _ = ps.Result()
		log.V(3).Infof("Pod %s accepted offer %v", podName, offer.Id.GetValue())
		return true, nil // stop, we found an offer
	})
	if matchingOffer != nil {
		if err != nil {
			log.Warningf("problems walking the offer registry: %v, attempting to continue", err)
		}
		return matchingOffer, acceptedSpec, nil
	}
	if err != nil {
		log.V(2).Infof("failed to find a fit for pod: %s, err = %v", podName, err)
		return nil, nil, err
	}
	log.V(2).Infof("failed to find a fit for pod: %s", podName)
	return nil, nil, errors.NoSuitableOffersErr
}

//get number of non-expired offers from  offer registry
func getNumberOffers(os offers.Registry) int {
	//walk offers and check it is stored in registry
	walked := 0
	walker1 := func(p offers.Perishable) (bool, error) {
		walked++
		return false, nil

	}
	os.Walk(walker1)
	return walked
}

// A first-come-first-serve scheduler: acquires the first offer that can support the task
func (fps *fcfsPodScheduler) SchedulePod(r offers.Registry, task *podtask.T) (offers.Perishable, error) {
	podName := fmt.Sprintf("%s/%s", task.Pod.Namespace, task.Pod.Name)
	var acceptedOffer offers.Perishable
	err := r.Walk(func(p offers.Perishable) (bool, error) {
		offer := p.Details()
		if offer == nil {
			return false, fmt.Errorf("nil offer while scheduling task %v", task.ID)
		}

		// check that the node actually exists. As offers are declined if not, the
		// case n==nil can only happen when the node object was deleted since the
		// offer came in.
		nodeName := offer.GetHostname()
		n := fps.lookupNode(nodeName)
		if n == nil {
			log.V(3).Infof("ignoring offer for node %s because node went away", nodeName)
			return false, nil
		}

		if fps.FitPredicate()(task, offer, n) {
			if p.Acquire() {
				acceptedOffer = p
				log.V(3).Infof("Pod %s accepted offer %v", podName, offer.Id.GetValue())
				return true, nil // stop, we found an offer
			}
		}
		return false, nil // continue
	})
	if acceptedOffer != nil {
		if err != nil {
			log.Warningf("problems walking the offer registry: %v, attempting to continue", err)
		}
		return acceptedOffer, nil
	}
	if err != nil {
		log.V(2).Infof("failed to find a fit for pod: %s, err = %v", podName, err)
		return nil, err
	}
	log.V(2).Infof("failed to find a fit for pod: %s", podName)
	return nil, errors.NoSuitableOffersErr
}