oci: join crio-conmon for cgroupfs

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

vendor/github.com/containerd/cgroups/cpuacct.go

@@ -0,0 +1,112 @@
+package cgroups
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+const nanosecondsInSecond = 1000000000
+
+var clockTicks = getClockTicks()
+
+func NewCpuacct(root string) *cpuacctController {
+	return &cpuacctController{
+		root: filepath.Join(root, string(Cpuacct)),
+	}
+}
+
+type cpuacctController struct {
+	root string
+}
+
+func (c *cpuacctController) Name() Name {
+	return Cpuacct
+}
+
+func (c *cpuacctController) Path(path string) string {
+	return filepath.Join(c.root, path)
+}
+
+func (c *cpuacctController) Stat(path string, stats *Stats) error {
+	user, kernel, err := c.getUsage(path)
+	if err != nil {
+		return err
+	}
+	total, err := readUint(filepath.Join(c.Path(path), "cpuacct.usage"))
+	if err != nil {
+		return err
+	}
+	percpu, err := c.percpuUsage(path)
+	if err != nil {
+		return err
+	}
+	stats.cpuMu.Lock()
+	cpu := stats.Cpu
+	if cpu == nil {
+		cpu = &CpuStat{}
+		stats.Cpu = cpu
+	}
+	stats.cpuMu.Unlock()
+	cpu.Usage.Total = total
+	cpu.Usage.User = user
+	cpu.Usage.Kernel = kernel
+	cpu.Usage.PerCpu = percpu
+	return nil
+}
+
+func (c *cpuacctController) percpuUsage(path string) ([]uint64, error) {
+	var usage []uint64
+	data, err := ioutil.ReadFile(filepath.Join(c.Path(path), "cpuacct.usage_percpu"))
+	if err != nil {
+		return nil, err
+	}
+	for _, v := range strings.Fields(string(data)) {
+		u, err := strconv.ParseUint(v, 10, 64)
+		if err != nil {
+			return nil, err
+		}
+		usage = append(usage, u)
+	}
+	return usage, nil
+}
+
+func (c *cpuacctController) getUsage(path string) (user uint64, kernel uint64, err error) {
+	statPath := filepath.Join(c.Path(path), "cpuacct.stat")
+	data, err := ioutil.ReadFile(statPath)
+	if err != nil {
+		return 0, 0, err
+	}
+	fields := strings.Fields(string(data))
+	if len(fields) != 4 {
+		return 0, 0, fmt.Errorf("%q is expected to have 4 fields", statPath)
+	}
+	for _, t := range []struct {
+		index int
+		name  string
+		value *uint64
+	}{
+		{
+			index: 0,
+			name:  "user",
+			value: &user,
+		},
+		{
+			index: 2,
+			name:  "system",
+			value: &kernel,
+		},
+	} {
+		if fields[t.index] != t.name {
+			return 0, 0, fmt.Errorf("expected field %q but found %q in %q", t.name, fields[t.index], statPath)
+		}
+		v, err := strconv.ParseUint(fields[t.index+1], 10, 64)
+		if err != nil {
+			return 0, 0, err
+		}
+		*t.value = v
+	}
+	return (user * nanosecondsInSecond) / clockTicks, (kernel * nanosecondsInSecond) / clockTicks, nil
+}