Golang String.Len方法代碼示例

// Index returns a list of items that match on the index function
// Index is thread-safe so long as you treat all items as immutable
func (c *threadSafeMap) Index(indexName string, obj interface{}) ([]interface{}, error) {
	c.lock.RLock()
	defer c.lock.RUnlock()

	indexFunc := c.indexers[indexName]
	if indexFunc == nil {
		return nil, fmt.Errorf("Index with name %s does not exist", indexName)
	}

	indexKeys, err := indexFunc(obj)
	if err != nil {
		return nil, err
	}
	index := c.indices[indexName]

	// need to de-dupe the return list.  Since multiple keys are allowed, this can happen.
	returnKeySet := sets.String{}
	for _, indexKey := range indexKeys {
		set := index[indexKey]
		for _, key := range set.List() {
			returnKeySet.Insert(key)
		}
	}

	list := make([]interface{}, 0, returnKeySet.Len())
	for absoluteKey := range returnKeySet {
		list = append(list, c.items[absoluteKey])
	}
	return list, nil
}

func runResourceTrackingTest(framework *Framework, podsPerNode int, nodeNames sets.String, resourceMonitor *resourceMonitor) {
	numNodes := nodeNames.Len()
	totalPods := podsPerNode * numNodes
	By(fmt.Sprintf("Creating a RC of %d pods and wait until all pods of this RC are running", totalPods))
	rcName := fmt.Sprintf("resource%d-%s", totalPods, string(util.NewUUID()))

	// TODO: Use a more realistic workload
	Expect(RunRC(RCConfig{
		Client:    framework.Client,
		Name:      rcName,
		Namespace: framework.Namespace.Name,
		Image:     "gcr.io/google_containers/pause:go",
		Replicas:  totalPods,
	})).NotTo(HaveOccurred())

	// Log once and flush the stats.
	resourceMonitor.LogLatest()
	resourceMonitor.Reset()

	By("Start monitoring resource usage")
	// Periodically dump the cpu summary until the deadline is met.
	// Note that without calling resourceMonitor.Reset(), the stats
	// would occupy increasingly more memory. This should be fine
	// for the current test duration, but we should reclaim the
	// entries if we plan to monitor longer (e.g., 8 hours).
	deadline := time.Now().Add(monitoringTime)
	for time.Now().Before(deadline) {
		Logf("Still running...%v left", deadline.Sub(time.Now()))
		time.Sleep(reportingPeriod)
		timeLeft := deadline.Sub(time.Now())
		Logf("Still running...%v left", timeLeft)
		if timeLeft < reportingPeriod {
			time.Sleep(timeLeft)
		} else {
			time.Sleep(reportingPeriod)
		}
		logPodsOnNodes(framework.Client, nodeNames.List())
	}

	By("Reporting overall resource usage")
	logPodsOnNodes(framework.Client, nodeNames.List())
	resourceMonitor.LogCPUSummary()
	resourceMonitor.LogLatest()

	By("Deleting the RC")
	DeleteRC(framework.Client, framework.Namespace.Name, rcName)
}

func TestHammerController(t *testing.T) {
	// This test executes a bunch of requests through the fake source and
	// controller framework to make sure there's no locking/threading
	// errors. If an error happens, it should hang forever or trigger the
	// race detector.

	// source simulates an apiserver object endpoint.
	source := framework.NewFakeControllerSource()

	// Let's do threadsafe output to get predictable test results.
	outputSetLock := sync.Mutex{}
	// map of key to operations done on the key
	outputSet := map[string][]string{}

	recordFunc := func(eventType string, obj interface{}) {
		key, err := framework.DeletionHandlingMetaNamespaceKeyFunc(obj)
		if err != nil {
			t.Errorf("something wrong with key: %v", err)
			key = "oops something went wrong with the key"
		}

		// Record some output when items are deleted.
		outputSetLock.Lock()
		defer outputSetLock.Unlock()
		outputSet[key] = append(outputSet[key], eventType)
	}

	// Make a controller which just logs all the changes it gets.
	_, controller := framework.NewInformer(
		source,
		&api.Pod{},
		time.Millisecond*100,
		framework.ResourceEventHandlerFuncs{
			AddFunc:    func(obj interface{}) { recordFunc("add", obj) },
			UpdateFunc: func(oldObj, newObj interface{}) { recordFunc("update", newObj) },
			DeleteFunc: func(obj interface{}) { recordFunc("delete", obj) },
		},
	)

	if controller.HasSynced() {
		t.Errorf("Expected HasSynced() to return false before we started the controller")
	}

	// Run the controller and run it until we close stop.
	stop := make(chan struct{})
	go controller.Run(stop)

	// Let's wait for the controller to do its initial sync
	time.Sleep(100 * time.Millisecond)
	if !controller.HasSynced() {
		t.Errorf("Expected HasSynced() to return true after the initial sync")
	}

	wg := sync.WaitGroup{}
	const threads = 3
	wg.Add(threads)
	for i := 0; i < threads; i++ {
		go func() {
			defer wg.Done()
			// Let's add a few objects to the source.
			currentNames := sets.String{}
			rs := rand.NewSource(rand.Int63())
			f := fuzz.New().NilChance(.5).NumElements(0, 2).RandSource(rs)
			r := rand.New(rs) // Mustn't use r and f concurrently!
			for i := 0; i < 100; i++ {
				var name string
				var isNew bool
				if currentNames.Len() == 0 || r.Intn(3) == 1 {
					f.Fuzz(&name)
					isNew = true
				} else {
					l := currentNames.List()
					name = l[r.Intn(len(l))]
				}

				pod := &api.Pod{}
				f.Fuzz(pod)
				pod.ObjectMeta.Name = name
				pod.ObjectMeta.Namespace = "default"
				// Add, update, or delete randomly.
				// Note that these pods are not valid-- the fake source doesn't
				// call validation or perform any other checking.
				if isNew {
					currentNames.Insert(name)
					source.Add(pod)
					continue
				}
				switch r.Intn(2) {
				case 0:
					currentNames.Insert(name)
					source.Modify(pod)
				case 1:
					currentNames.Delete(name)
					source.Delete(pod)
				}
			}
		}()
	}
	wg.Wait()

//.........這裏部分代碼省略.........