docker/daemon/stats_collector_unix.go

72 строки
1.8 KiB
Go

// +build !windows,!solaris
package daemon
import (
"fmt"
"os"
"strconv"
"strings"
sysinfo "github.com/docker/docker/pkg/system"
"github.com/opencontainers/runc/libcontainer/system"
)
// platformNewStatsCollector performs platform specific initialisation of the
// statsCollector structure.
func platformNewStatsCollector(s *statsCollector) {
s.clockTicksPerSecond = uint64(system.GetClockTicks())
meminfo, err := sysinfo.ReadMemInfo()
if err == nil && meminfo.MemTotal > 0 {
s.machineMemory = uint64(meminfo.MemTotal)
}
}
const nanoSecondsPerSecond = 1e9
// getSystemCPUUsage returns the host system's cpu usage in
// nanoseconds. An error is returned if the format of the underlying
// file does not match.
//
// Uses /proc/stat defined by POSIX. Looks for the cpu
// statistics line and then sums up the first seven fields
// provided. See `man 5 proc` for details on specific field
// information.
func (s *statsCollector) getSystemCPUUsage() (uint64, error) {
var line string
f, err := os.Open("/proc/stat")
if err != nil {
return 0, err
}
defer func() {
s.bufReader.Reset(nil)
f.Close()
}()
s.bufReader.Reset(f)
err = nil
for err == nil {
line, err = s.bufReader.ReadString('\n')
if err != nil {
break
}
parts := strings.Fields(line)
switch parts[0] {
case "cpu":
if len(parts) < 8 {
return 0, fmt.Errorf("invalid number of cpu fields")
}
var totalClockTicks uint64
for _, i := range parts[1:8] {
v, err := strconv.ParseUint(i, 10, 64)
if err != nil {
return 0, fmt.Errorf("Unable to convert value %s to int: %s", i, err)
}
totalClockTicks += v
}
return (totalClockTicks * nanoSecondsPerSecond) /
s.clockTicksPerSecond, nil
}
}
return 0, fmt.Errorf("invalid stat format. Error trying to parse the '/proc/stat' file")
}