PS performance cleanups

By not getting data that we don't need and adding more locking
functions under the batch, we are able to cut the time for listing
50 containers in half.  More to come.

Signed-off-by: baude <bbaude@redhat.com>

Closes: #325
Approved by: mheon

1 files changed, 51 insertions, 33 deletions

diff --git a/cmd/podman/ps.go b/cmd/podman/ps.go
index e4c90187b..d5bbe6f67 100644
--- a/cmd/podman/ps.go
+++ b/cmd/podman/ps.go
@@ -397,13 +397,16 @@ func (p *psTemplateParams) headerMap() map[string]string {
 // getTemplateOutput returns the modified container information
 func getTemplateOutput(containers []*libpod.Container, opts psOptions) ([]psTemplateParams, error) {
 	var (
-		psOutput      []psTemplateParams
-		status, ctrID string
-		conConfig     *libpod.ContainerConfig
-		conState      libpod.ContainerStatus
-		err           error
-		exitCode      int32
-		pid           int
+		psOutput            []psTemplateParams
+		status, ctrID, size string
+		conConfig           *libpod.ContainerConfig
+		conState            libpod.ContainerStatus
+		err                 error
+		exitCode            int32
+		pid                 int
+		rootFsSize, rwSize  int64
+		ns                  *namespace
+		startedTime         time.Time
 	)
 
 	for _, ctr := range containers {
@@ -418,20 +421,41 @@ func getTemplateOutput(containers []*libpod.Container, opts psOptions) ([]psTemp
 			if err != nil {
 				return errors.Wrapf(err, "unable to obtain container exit code")
 			}
-			pid, err = c.PID()
+			startedTime, err = c.StartedTime()
 			if err != nil {
-				return errors.Wrapf(err, "unable to obtain container pid")
+				logrus.Errorf("error getting started time for %q: %v", c.ID(), err)
 			}
+
+			if !opts.size && !opts.namespace {
+				return nil
+			}
+
+			if opts.namespace {
+				pid, err = c.PID()
+				if err != nil {
+					return errors.Wrapf(err, "unable to obtain container pid")
+				}
+			}
+			if opts.size {
+				rootFsSize, err = c.RootFsSize()
+				if err != nil {
+					logrus.Errorf("error getting root fs size for %q: %v", c.ID(), err)
+				}
+
+				rwSize, err = c.RWSize()
+				if err != nil {
+					logrus.Errorf("error getting rw size for %q: %v", c.ID(), err)
+				}
+
+				size = units.HumanSizeWithPrecision(float64(rwSize), 3) + " (virtual " + units.HumanSizeWithPrecision(float64(rootFsSize), 3) + ")"
+			}
+
 			return nil
 		})
 		if batchErr != nil {
 			return nil, err
 		}
 		runningFor := ""
-		startedTime, err := ctr.StartedTime()
-		if err != nil {
-			logrus.Errorf("error getting started time for %q: %v", ctr.ID(), err)
-		}
 		// If the container has not be started, the "zero" value of time is 0001-01-01 00:00:00 +0000 UTC
 		// which would make the time elapsed about a few hundred of years. So checking for the "zero" value of time.Time
 		if startedTime != (time.Time{}) {
@@ -439,14 +463,6 @@ func getTemplateOutput(containers []*libpod.Container, opts psOptions) ([]psTemp
 		}
 		createdAt := conConfig.CreatedTime.Format("2006-01-02 15:04:05 -0700 MST")
 		imageName := conConfig.RootfsImageName
-		rootFsSize, err := ctr.RootFsSize()
-		if err != nil {
-			logrus.Errorf("error getting root fs size for %q: %v", ctr.ID(), err)
-		}
-		rwSize, err := ctr.RWSize()
-		if err != nil {
-			logrus.Errorf("error getting rw size for %q: %v", ctr.ID(), err)
-		}
 
 		var createArtifact createConfig
 		artifact, err := ctr.GetArtifact("create-config")
@@ -457,16 +473,16 @@ func getTemplateOutput(containers []*libpod.Container, opts psOptions) ([]psTemp
 		} else {
 			logrus.Errorf("couldn't get some ps information, error getting artifact %q: %v", ctr.ID(), err)
 		}
+		if opts.namespace {
+			ns = getNamespaces(pid)
+		}
 
 		// TODO We currently dont have the ability to get many of
 		// these data items.  Uncomment as progress is made
-
-		command := strings.Join(ctr.Spec().Process.Args, " ")
-		ports := getPorts(ctr.Config().PortMappings)
+		command := strings.Join(conConfig.Spec.Process.Args, " ")
+		ports := getPorts(conConfig.PortMappings)
 		mounts := getMounts(createArtifact.Volumes, opts.noTrunc)
-		size := units.HumanSizeWithPrecision(float64(rwSize), 3) + " (virtual " + units.HumanSizeWithPrecision(float64(rootFsSize), 3) + ")"
 		labels := formatLabels(ctr.Labels())
-		ns := getNamespaces(pid)
 
 		switch conState {
 		case libpod.ContainerStateStopped:
@@ -502,13 +518,15 @@ func getTemplateOutput(containers []*libpod.Container, opts psOptions) ([]psTemp
 			Labels:     labels,
 			Mounts:     mounts,
 			PID:        pid,
-			Cgroup:     ns.Cgroup,
-			IPC:        ns.IPC,
-			MNT:        ns.MNT,
-			NET:        ns.NET,
-			PIDNS:      ns.PID,
-			User:       ns.User,
-			UTS:        ns.UTS,
+		}
+		if opts.namespace {
+			params.Cgroup = ns.Cgroup
+			params.IPC = ns.IPC
+			params.MNT = ns.MNT
+			params.NET = ns.NET
+			params.PIDNS = ns.PIDNS
+			params.User = ns.User
+			params.UTS = ns.UTS
 		}
 		psOutput = append(psOutput, params)
 	}