Golang String.List方法代碼示例

// Test public interface
func doTestIndex(t *testing.T, indexer Indexer) {
	mkObj := func(id string, val string) testStoreObject {
		return testStoreObject{id: id, val: val}
	}

	// Test Index
	expected := map[string]sets.String{}
	expected["b"] = sets.NewString("a", "c")
	expected["f"] = sets.NewString("e")
	expected["h"] = sets.NewString("g")
	indexer.Add(mkObj("a", "b"))
	indexer.Add(mkObj("c", "b"))
	indexer.Add(mkObj("e", "f"))
	indexer.Add(mkObj("g", "h"))
	{
		for k, v := range expected {
			found := sets.String{}
			indexResults, err := indexer.Index("by_val", mkObj("", k))
			if err != nil {
				t.Errorf("Unexpected error %v", err)
			}
			for _, item := range indexResults {
				found.Insert(item.(testStoreObject).id)
			}
			items := v.List()
			if !found.HasAll(items...) {
				t.Errorf("missing items, index %s, expected %v but found %v", k, items, found.List())
			}
		}
	}
}

// ChooseZone implements our heuristics for choosing a zone for volume creation based on the volume name
// Volumes are generally round-robin-ed across all active zones, using the hash of the PVC Name.
// However, if the PVCName ends with `-<integer>`, we will hash the prefix, and then add the integer to the hash.
// This means that a PetSet's volumes (`claimname-petsetname-id`) will spread across available zones,
// assuming the id values are consecutive.
func ChooseZoneForVolume(zones sets.String, pvcName string) string {
	// We create the volume in a zone determined by the name
	// Eventually the scheduler will coordinate placement into an available zone
	var hash uint32
	var index uint32

	if pvcName == "" {
		// We should always be called with a name; this shouldn't happen
		glog.Warningf("No name defined during volume create; choosing random zone")

		hash = rand.Uint32()
	} else {
		hashString := pvcName

		// Heuristic to make sure that volumes in a PetSet are spread across zones
		// PetSet PVCs are (currently) named ClaimName-PetSetName-Id,
		// where Id is an integer index
		lastDash := strings.LastIndexByte(pvcName, '-')
		if lastDash != -1 {
			petIDString := pvcName[lastDash+1:]
			petID, err := strconv.ParseUint(petIDString, 10, 32)
			if err == nil {
				// Offset by the pet id, so we round-robin across zones
				index = uint32(petID)
				// We still hash the volume name, but only the base
				hashString = pvcName[:lastDash]
				glog.V(2).Infof("Detected PetSet-style volume name %q; index=%d", pvcName, index)
			}
		}

		// We hash the (base) volume name, so we don't bias towards the first N zones
		h := fnv.New32()
		h.Write([]byte(hashString))
		hash = h.Sum32()
	}

	// Zones.List returns zones in a consistent order (sorted)
	// We do have a potential failure case where volumes will not be properly spread,
	// if the set of zones changes during PetSet volume creation.  However, this is
	// probably relatively unlikely because we expect the set of zones to be essentially
	// static for clusters.
	// Hopefully we can address this problem if/when we do full scheduler integration of
	// PVC placement (which could also e.g. avoid putting volumes in overloaded or
	// unhealthy zones)
	zoneSlice := zones.List()
	zone := zoneSlice[(hash+index)%uint32(len(zoneSlice))]

	glog.V(2).Infof("Creating volume for PVC %q; chose zone=%q from zones=%q", pvcName, zone, zoneSlice)
	return zone
}

func CheckSetEq(lhs, rhs sets.String) bool {
	return lhs.HasAll(rhs.List()...) && rhs.HasAll(lhs.List()...)
}