virtcontainers: improve algorithm to find containers

Do not iterate over a map to find a container, use map built-in method instead. fixes kata-containers#2254 Signed-off-by: Julio Montes <julio.montes@intel.com>
katabuilder · Nov 22, 2019 · 7f67b9f · 7f67b9f
1 parent fea166d
commit 7f67b9f
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Showing 2 changed files with 42 additions and 47 deletions.
diff --git a/virtcontainers/api.go b/virtcontainers/api.go
@@ -589,42 +589,40 @@ func StatusContainer(ctx context.Context, sandboxID, containerID string) (Contai
 // taken from the caller, even if we simply return the container status without
 // taking any action regarding the container.
 func statusContainer(sandbox *Sandbox, containerID string) (ContainerStatus, error) {
-	for _, container := range sandbox.containers {
-		if container.id == containerID {
-			// We have to check for the process state to make sure
-			// we update the status in case the process is supposed
-			// to be running but has been killed or terminated.
-			if (container.state.State == types.StateReady ||
-				container.state.State == types.StateRunning ||
-				container.state.State == types.StatePaused) &&
-				container.process.Pid > 0 {
-
-				running, err := isShimRunning(container.process.Pid)
-				if err != nil {
-					return ContainerStatus{}, err
-				}
+	if container, ok := sandbox.containers[containerID]; ok {
+		// We have to check for the process state to make sure
+		// we update the status in case the process is supposed
+		// to be running but has been killed or terminated.
+		if (container.state.State == types.StateReady ||
+			container.state.State == types.StateRunning ||
+			container.state.State == types.StatePaused) &&
+			container.process.Pid > 0 {
+
+			running, err := isShimRunning(container.process.Pid)
+			if err != nil {
+				return ContainerStatus{}, err
+			}
 
-				if !running {
-					virtLog.WithFields(logrus.Fields{
-						"state": container.state.State,
-						"pid":   container.process.Pid}).
-						Info("container isn't running")
-					if err := container.stop(true); err != nil {
-						return ContainerStatus{}, err
-					}
+			if !running {
+				virtLog.WithFields(logrus.Fields{
+					"state": container.state.State,
+					"pid":   container.process.Pid}).
+					Info("container isn't running")
+				if err := container.stop(true); err != nil {
+					return ContainerStatus{}, err
 				}
 			}
-
-			return ContainerStatus{
-				ID:          container.id,
-				State:       container.state,
-				PID:         container.process.Pid,
-				StartTime:   container.process.StartTime,
-				RootFs:      container.config.RootFs.Target,
-				Spec:        container.GetOCISpec(),
-				Annotations: container.config.Annotations,
-			}, nil
 		}
+
+		return ContainerStatus{
+			ID:          container.id,
+			State:       container.state,
+			PID:         container.process.Pid,
+			StartTime:   container.process.StartTime,
+			RootFs:      container.config.RootFs.Target,
+			Spec:        container.GetOCISpec(),
+			Annotations: container.config.Annotations,
+		}, nil
 	}
 
 	// No matching containers in the sandbox

diff --git a/virtcontainers/sandbox.go b/virtcontainers/sandbox.go
@@ -752,10 +752,8 @@ func (s *Sandbox) findContainer(containerID string) (*Container, error) {
 		return nil, vcTypes.ErrNeedContainerID
 	}
 
-	for id, c := range s.containers {
-		if containerID == id {
-			return c, nil
-		}
+	if c, ok := s.containers[containerID]; ok {
+		return c, nil
 	}
 
 	return nil, errors.Wrapf(vcTypes.ErrNoSuchContainer, "Could not find the container %q from the sandbox %q containers list",
@@ -1324,21 +1322,20 @@ func (s *Sandbox) StatusContainer(containerID string) (ContainerStatus, error) {
 		return ContainerStatus{}, vcTypes.ErrNeedContainerID
 	}
 
-	for id, c := range s.containers {
+	if c, ok := s.containers[containerID]; ok {
 		rootfs := c.config.RootFs.Source
 		if c.config.RootFs.Mounted {
 			rootfs = c.config.RootFs.Target
 		}
-		if id == containerID {
-			return ContainerStatus{
-				ID:          c.id,
-				State:       c.state,
-				PID:         c.process.Pid,
-				StartTime:   c.process.StartTime,
-				RootFs:      rootfs,
-				Annotations: c.config.Annotations,
-			}, nil
-		}
+
+		return ContainerStatus{
+			ID:          c.id,
+			State:       c.state,
+			PID:         c.process.Pid,
+			StartTime:   c.process.StartTime,
+			RootFs:      rootfs,
+			Annotations: c.config.Annotations,
+		}, nil
 	}
 
 	return ContainerStatus{}, vcTypes.ErrNoSuchContainer