Make explicit the use of InMemoryStorage in Manager.

The current structure is a remnant of when the in memory storage was one
of the options for backing store. Today, we always have the memory
storage with an optional "backend storage" plugin. This commit makes the
InMemoryStorage use explicit.

cadvisor.go

@@ -61,7 +61,7 @@ func main() {
 
 	setMaxProcs()
 
-	storageDriver, err := NewStorageDriver(*argDbDriver)
+	memoryStorage, err := NewMemoryStorage(*argDbDriver)
 	if err != nil {
 		glog.Fatalf("Failed to connect to database: %s", err)
 	}
@@ -71,7 +71,7 @@ func main() {
 		glog.Fatalf("Failed to create a system interface: %s", err)
 	}
 
-	containerManager, err := manager.New(storageDriver, sysFs)
+	containerManager, err := manager.New(memoryStorage, sysFs)
 	if err != nil {
 		glog.Fatalf("Failed to create a Container Manager: %s", err)
 	}

manager/manager.go

@@ -29,7 +29,7 @@ import (
 	"github.com/google/cadvisor/container"
 	"github.com/google/cadvisor/container/docker"
 	"github.com/google/cadvisor/info"
-	"github.com/google/cadvisor/storage"
+	"github.com/google/cadvisor/storage/memory"
 	"github.com/google/cadvisor/utils/cpuload"
 	"github.com/google/cadvisor/utils/sysfs"
 )
@@ -65,10 +65,10 @@ type Manager interface {
 	GetVersionInfo() (*info.VersionInfo, error)
 }
 
-// New takes a driver and returns a new manager.
-func New(driver storage.StorageDriver, sysfs sysfs.SysFs) (Manager, error) {
-	if driver == nil {
-		return nil, fmt.Errorf("nil storage driver!")
+// New takes a memory storage and returns a new manager.
+func New(memoryStorage *memory.InMemoryStorage, sysfs sysfs.SysFs) (Manager, error) {
+	if memoryStorage == nil {
+		return nil, fmt.Errorf("manager requires memory storage")
 	}
 
 	// Detect the container we are running on.
@@ -81,7 +81,7 @@ func New(driver storage.StorageDriver, sysfs sysfs.SysFs) (Manager, error) {
 	newManager := &manager{
 		containers:        make(map[namespacedContainerName]*containerData),
 		quitChannels:      make([]chan error, 0, 2),
-		storageDriver:     driver,
+		memoryStorage:     memoryStorage,
 		cadvisorContainer: selfContainer,
 	}
 
@@ -114,7 +114,7 @@ type namespacedContainerName struct {
 type manager struct {
 	containers             map[namespacedContainerName]*containerData
 	containersLock         sync.RWMutex
-	storageDriver          storage.StorageDriver
+	memoryStorage          *memory.InMemoryStorage
 	machineInfo            info.MachineInfo
 	versionInfo            info.VersionInfo
 	quitChannels           []chan error
@@ -250,7 +250,7 @@ func (self *manager) containerDataToContainerInfo(cont *containerData, query *in
 		return nil, err
 	}
 
-	stats, err := self.storageDriver.RecentStats(cinfo.Name, query.NumStats)
+	stats, err := self.memoryStorage.RecentStats(cinfo.Name, query.NumStats)
 	if err != nil {
 		return nil, err
 	}
@@ -380,7 +380,7 @@ func (m *manager) createContainer(containerName string) error {
 		return err
 	}
 	logUsage := *logCadvisorUsage && containerName == m.cadvisorContainer
-	cont, err := newContainerData(containerName, m.storageDriver, handler, m.loadReader, logUsage)
+	cont, err := newContainerData(containerName, m.memoryStorage, handler, m.loadReader, logUsage)
 	if err != nil {
 		return err
 	}

manager/manager_test.go

@@ -26,24 +26,21 @@ import (
 	"github.com/google/cadvisor/container/docker"
 	"github.com/google/cadvisor/info"
 	itest "github.com/google/cadvisor/info/test"
-	stest "github.com/google/cadvisor/storage/test"
+	"github.com/google/cadvisor/storage/memory"
 	"github.com/google/cadvisor/utils/sysfs/fakesysfs"
 )
 
 // TODO(vmarmol): Refactor these tests.
 
 func createManagerAndAddContainers(
-	driver *stest.MockStorageDriver,
+	memoryStorage *memory.InMemoryStorage,
 	sysfs *fakesysfs.FakeSysFs,
 	containers []string,
 	f func(*container.MockContainerHandler),
 	t *testing.T,
 ) *manager {
-	if driver == nil {
-		driver = &stest.MockStorageDriver{}
-	}
 	container.ClearContainerHandlerFactories()
-	mif, err := New(driver, sysfs)
+	mif, err := New(memoryStorage, sysfs)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -55,7 +52,7 @@ func createManagerAndAddContainers(
 				spec,
 				nil,
 			).Once()
-			cont, err := newContainerData(name, driver, mockHandler, nil, false)
+			cont, err := newContainerData(name, memoryStorage, mockHandler, nil, false)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -87,24 +84,25 @@ func expectManagerWithContainers(containers []string, query *info.ContainerInfoR
 		infosMap[container] = itest.GenerateRandomContainerInfo(container, 4, query, 1*time.Second)
 	}
 
-	driver := &stest.MockStorageDriver{}
+	memoryStorage := memory.New(query.NumStats, nil)
 	sysfs := &fakesysfs.FakeSysFs{}
 	m := createManagerAndAddContainers(
-		driver,
+		memoryStorage,
 		sysfs,
 		containers,
 		func(h *container.MockContainerHandler) {
 			cinfo := infosMap[h.Name]
-			stats := cinfo.Stats
+			ref, err := h.ContainerReference()
+			if err != nil {
+				t.Error(err)
+			}
+			for _, stat := range cinfo.Stats {
+				err = memoryStorage.AddStats(ref, stat)
+				if err != nil {
+					t.Error(err)
+				}
+			}
 			spec := cinfo.Spec
-			driver.On(
-				"RecentStats",
-				h.Name,
-				query.NumStats,
-			).Return(
-				stats,
-				nil,
-			)
 
 			h.On("ListContainers", container.ListSelf).Return(
 				[]info.ContainerReference(nil),
@@ -209,7 +207,8 @@ func TestDockerContainersInfo(t *testing.T) {
 }
 
 func TestNew(t *testing.T) {
-	manager, err := New(&stest.MockStorageDriver{}, &fakesysfs.FakeSysFs{})
+	memoryStorage := memory.New(60, nil)
+	manager, err := New(memoryStorage, &fakesysfs.FakeSysFs{})
 	if err != nil {
 		t.Fatalf("Expected manager.New to succeed: %s", err)
 	}

storagedriver.go

@@ -38,7 +38,8 @@ var argDbBufferDuration = flag.Duration("storage_driver_buffer_duration", 60*tim
 
 const statsRequestedByUI = 60
 
-func NewStorageDriver(driverName string) (*memory.InMemoryStorage, error) {
+// Creates a memory storage with an optional backend storage option.
+func NewMemoryStorage(backendStorageName string) (*memory.InMemoryStorage, error) {
 	var storageDriver *memory.InMemoryStorage
 	var backendStorage storage.StorageDriver
 	var err error
@@ -48,7 +49,7 @@ func NewStorageDriver(driverName string) (*memory.InMemoryStorage, error) {
 		// The UI requests the most recent 60 stats by default.
 		statsToCache = statsRequestedByUI
 	}
-	switch driverName {
+	switch backendStorageName {
 	case "":
 		backendStorage = nil
 	case "influxdb":
@@ -79,14 +80,18 @@ func NewStorageDriver(driverName string) (*memory.InMemoryStorage, error) {
 			*argDbTable,
 			*argDbName,
 		)
-
 	default:
-		err = fmt.Errorf("unknown database driver: %v", *argDbDriver)
+		err = fmt.Errorf("unknown backend storage driver: %v", *argDbDriver)
 	}
 	if err != nil {
 		return nil, err
 	}
-	glog.Infof("Caching %d recent stats in memory; using \"%v\" storage driver\n", statsToCache, driverName)
+	if backendStorageName != "" {
+		glog.Infof("Using backend storage type %q", backendStorageName)
+	} else {
+		glog.Infof("No backend storage selected")
+	}
+	glog.Info("Caching %d stats in memory", statsToCache)
 	storageDriver = memory.New(statsToCache, backendStorage)
 	return storageDriver, nil
 }