Merge pull request #6583 from thaJeztah/stats_cleanups

cli/command/container: cleanup stats code

Author: thaJeztah

cli/command/container/stats_helpers.go

@@ -50,15 +50,10 @@ func (s *stats) isKnownContainer(cid string) (int, bool) {
 }
 
 func collect(ctx context.Context, s *Stats, cli client.ContainerAPIClient, streamStats bool, waitFirst *sync.WaitGroup) { //nolint:gocyclo
-	var (
-		getFirst       bool
-		previousCPU    uint64
-		previousSystem uint64
-		u              = make(chan error, 1)
-	)
+	var getFirst bool
 
 	defer func() {
-		// if error happens and we get nothing of stats, release wait group whatever
+		// if error happens, and we get nothing of stats, release wait group whatever
 		if !getFirst {
 			getFirst = true
 			waitFirst.Done()
@@ -71,21 +66,15 @@ func collect(ctx context.Context, s *Stats, cli client.ContainerAPIClient, strea
 		return
 	}
 
+	u := make(chan error, 1)
 	go func() {
 		defer response.Body.Close()
 		dec := json.NewDecoder(response.Body)
 		for {
 			if ctx.Err() != nil {
 				return
 			}
-			var (
-				v                      *container.StatsResponse
-				memPercent, cpuPercent float64
-				blkRead, blkWrite      uint64 // Only used on Linux
-				mem, memLimit          float64
-				pidsStatsCurrent       uint64
-			)
-
+			var v container.StatsResponse
 			if err := dec.Decode(&v); err != nil {
 				dec = json.NewDecoder(io.MultiReader(dec.Buffered(), response.Body))
 				u <- err
@@ -96,35 +85,36 @@ func collect(ctx context.Context, s *Stats, cli client.ContainerAPIClient, strea
 				continue
 			}
 
-			if daemonOSType != "windows" {
-				previousCPU = v.PreCPUStats.CPUUsage.TotalUsage
-				previousSystem = v.PreCPUStats.SystemUsage
-				cpuPercent = calculateCPUPercentUnix(previousCPU, previousSystem, v)
-				blkRead, blkWrite = calculateBlockIO(v.BlkioStats)
-				mem = calculateMemUsageUnixNoCache(v.MemoryStats)
-				memLimit = float64(v.MemoryStats.Limit)
-				memPercent = calculateMemPercentUnixNoCache(memLimit, mem)
-				pidsStatsCurrent = v.PidsStats.Current
+			if daemonOSType == "windows" {
+				netRx, netTx := calculateNetwork(v.Networks)
+				s.SetStatistics(StatsEntry{
+					Name:          v.Name,
+					ID:            v.ID,
+					CPUPercentage: calculateCPUPercentWindows(&v),
+					Memory:        float64(v.MemoryStats.PrivateWorkingSet),
+					NetworkRx:     netRx,
+					NetworkTx:     netTx,
+					BlockRead:     float64(v.StorageStats.ReadSizeBytes),
+					BlockWrite:    float64(v.StorageStats.WriteSizeBytes),
+				})
 			} else {
-				cpuPercent = calculateCPUPercentWindows(v)
-				blkRead = v.StorageStats.ReadSizeBytes
-				blkWrite = v.StorageStats.WriteSizeBytes
-				mem = float64(v.MemoryStats.PrivateWorkingSet)
+				memUsage := calculateMemUsageUnixNoCache(v.MemoryStats)
+				netRx, netTx := calculateNetwork(v.Networks)
+				blkRead, blkWrite := calculateBlockIO(v.BlkioStats)
+				s.SetStatistics(StatsEntry{
+					Name:             v.Name,
+					ID:               v.ID,
+					CPUPercentage:    calculateCPUPercentUnix(v.PreCPUStats, v.CPUStats),
+					Memory:           memUsage,
+					MemoryPercentage: calculateMemPercentUnixNoCache(float64(v.MemoryStats.Limit), memUsage),
+					MemoryLimit:      float64(v.MemoryStats.Limit),
+					NetworkRx:        netRx,
+					NetworkTx:        netTx,
+					BlockRead:        float64(blkRead),
+					BlockWrite:       float64(blkWrite),
+					PidsCurrent:      v.PidsStats.Current,
+				})
 			}
-			netRx, netTx := calculateNetwork(v.Networks)
-			s.SetStatistics(StatsEntry{
-				Name:             v.Name,
-				ID:               v.ID,
-				CPUPercentage:    cpuPercent,
-				Memory:           mem,
-				MemoryPercentage: memPercent,
-				MemoryLimit:      memLimit,
-				NetworkRx:        netRx,
-				NetworkTx:        netTx,
-				BlockRead:        float64(blkRead),
-				BlockWrite:       float64(blkWrite),
-				PidsCurrent:      pidsStatsCurrent,
-			})
 			u <- nil
 			if !streamStats {
 				return
@@ -165,18 +155,18 @@ func collect(ctx context.Context, s *Stats, cli client.ContainerAPIClient, strea
 	}
 }
 
-func calculateCPUPercentUnix(previousCPU, previousSystem uint64, v *container.StatsResponse) float64 {
+func calculateCPUPercentUnix(previousCPU container.CPUStats, curCPUStats container.CPUStats) float64 {
 	var (
 		cpuPercent = 0.0
 		// calculate the change for the cpu usage of the container in between readings
-		cpuDelta = float64(v.CPUStats.CPUUsage.TotalUsage) - float64(previousCPU)
+		cpuDelta = float64(curCPUStats.CPUUsage.TotalUsage) - float64(previousCPU.CPUUsage.TotalUsage)
 		// calculate the change for the entire system between readings
-		systemDelta = float64(v.CPUStats.SystemUsage) - float64(previousSystem)
-		onlineCPUs  = float64(v.CPUStats.OnlineCPUs)
+		systemDelta = float64(curCPUStats.SystemUsage) - float64(previousCPU.SystemUsage)
+		onlineCPUs  = float64(curCPUStats.OnlineCPUs)
 	)
 
 	if onlineCPUs == 0.0 {
-		onlineCPUs = float64(len(v.CPUStats.CPUUsage.PercpuUsage))
+		onlineCPUs = float64(len(curCPUStats.CPUUsage.PercpuUsage))
 	}
 	if systemDelta > 0.0 && cpuDelta > 0.0 {
 		cpuPercent = (cpuDelta / systemDelta) * onlineCPUs * 100.0
@@ -188,13 +178,11 @@ func calculateCPUPercentWindows(v *container.StatsResponse) float64 {
 	// Max number of 100ns intervals between the previous time read and now
 	possIntervals := uint64(v.Read.Sub(v.PreRead).Nanoseconds()) // Start with number of ns intervals
 	possIntervals /= 100                                         // Convert to number of 100ns intervals
-	possIntervals *= uint64(v.NumProcs)                          // Multiple by the number of processors
-
-	// Intervals used
-	intervalsUsed := v.CPUStats.CPUUsage.TotalUsage - v.PreCPUStats.CPUUsage.TotalUsage
+	possIntervals *= uint64(v.NumProcs)                          // Multiply by the number of processors
 
 	// Percentage avoiding divide-by-zero
 	if possIntervals > 0 {
+		intervalsUsed := v.CPUStats.CPUUsage.TotalUsage - v.PreCPUStats.CPUUsage.TotalUsage
 		return float64(intervalsUsed) / float64(possIntervals) * 100.0
 	}
 	return 0.00