package cmd

import (
	"context"
)

const (
	memTotal     = "total"
	memUsed      = "used"
	memFree      = "free"
	memBuffers   = "buffers"
	memCache     = "cache"
	memUsedPerc  = "used_perc"
	memShared    = "shared"
	memAvailable = "available"
)

var (
	memTotalMD     = NewGaugeMD(memTotal, "Total memory on the node")
	memUsedMD      = NewGaugeMD(memUsed, "Used memory on the node")

					if hm.CPU.CPUCount > 0 {
						perc := math.Round(ls.Load1*100*100/float64(hm.CPU.CPUCount)) / 100
						updateResourceMetrics(cpuSubsystem, cpuLoad1Perc, perc, labels, false)
						perc = math.Round(ls.Load5*100*100/float64(hm.CPU.CPUCount)) / 100
						updateResourceMetrics(cpuSubsystem, cpuLoad5Perc, perc, labels, false)
						perc = math.Round(ls.Load15*100*100/float64(hm.CPU.CPUCount)) / 100

	cpuMetrics, _ := c.cpuMetrics.Get()

	if cpuMetrics.LoadStat != nil {
		m.Set(sysCPULoad, cpuMetrics.LoadStat.Load1)
		perc := cpuMetrics.LoadStat.Load1 * 100 / float64(cpuMetrics.CPUCount)
		m.Set(sysCPULoadPerc, math.Round(perc*100)/100)
	}

	ts := cpuMetrics.TimesStat
	tot := ts.User + ts.System + ts.Idle + ts.Iowait + ts.Nice + ts.Steal
	cpuUserVal := math.Round(ts.User/tot*100*100) / 100

| `minio_node_drive_reads_per_sec`     | Reads per second on a drive.                             |
| `minio_node_drive_reads_kb_per_sec`  | Kilobytes read per second on a drive.                    |
| `minio_node_drive_reads_await`       | Average time for read requests to be served on a drive.  |
| `minio_node_drive_writes_per_sec`    | Writes per second on a drive.                            |

| `minio_system_drive_reads_per_sec`             | `gauge`   | Reads per second on a drive                                        | `drive,set_index,drive_index,pool_index,server`     |
| `minio_system_drive_reads_kb_per_sec`          | `gauge`   | Kilobytes read per second on a drive                               | `drive,set_index,drive_index,pool_index,server`     |

	driveCount        = "count"

	// iostat related
	driveReadsPerSec    = "reads_per_sec"
	driveReadsKBPerSec  = "reads_kb_per_sec"
	driveReadsAwait     = "reads_await"
	driveWritesPerSec   = "writes_per_sec"
	driveWritesKBPerSec = "writes_kb_per_sec"
	driveWritesAwait    = "writes_await"
	drivePercUtil       = "perc_util"
)

var (
	driveUsedBytesMD = NewGaugeMD(driveUsedBytes,

// flags and shouldn't be considered as replacement
// for os.OpenFile().
func LockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
	return lockedOpenFile(path, flag, perm, 0)
}

// Open - Call os.OpenFile
func Open(path string, flag int, perm os.FileMode) (*os.File, error) {
	return os.OpenFile(path, flag, perm)

}

// OpenFile captures time taken to call os.OpenFile
func OpenFile(name string, flag int, perm os.FileMode) (f *os.File, err error) {
	switch flag & writeMode {
	case writeMode:
		defer updateOSMetrics(osMetricOpenFileW, name)(err)
	default:
		defer updateOSMetrics(osMetricOpenFileR, name)(err)
	}
	return os.OpenFile(name, flag, perm)
}

// Access captures time taken to call syscall.Access()

)

func (er erasureObjects) getOnlineDisks() (newDisks []StorageAPI) {
	disks := er.getDisks()
	var wg sync.WaitGroup
	var mu sync.Mutex
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for _, i := range r.Perm(len(disks)) {
		i := i
		wg.Add(1)
		go func() {
			defer wg.Done()
			if disks[i] == nil {
				return
			}
			di, err := disks[i].DiskInfo(context.Background(), DiskInfoOptions{})

// ODirectPlatform indicates if the platform supports O_DIRECT
const ODirectPlatform = true

// OpenFileDirectIO - bypass kernel cache.
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.
func DisableDirectIO(f *os.File) error {
	fd := f.Fd()
	flag, err := unix.FcntlInt(fd, unix.F_GETFL, 0)
	if err != nil {