"net/http/httptrace"
	"sync/atomic"
	"time"
)

var globalStats = struct {
	errs uint64

	tcpDialErrs                 uint64
	tcpDialCount                uint64
	tcpDialTotalDur             uint64
	tcpTimeForFirstByteTotalDur uint64
}{}

// RPCStats holds information about the DHCP/TCP metrics and errors
type RPCStats struct {
	Errs uint64

	DialAvgDuration uint64
	TTFBAvgDuration uint64
	DialErrs        uint64

func checkDiskFatalErrs(errs []error) error {
	// This returns a common error if all errors are
	// same errors, then there is no point starting
	// the server.
	if countErrs(errs, errUnsupportedDisk) == len(errs) {
		return errUnsupportedDisk
	}

	if countErrs(errs, errDiskAccessDenied) == len(errs) {
		return errDiskAccessDenied
	}

	if countErrs(errs, errFileAccessDenied) == len(errs) {

// upon Wait() errors are returned collected from all tasks.
func WithNPeers(nerrs int) *NotificationGroup {
	if nerrs <= 0 {
		nerrs = 1
	}
	wk, _ := workers.New(nerrs)
	return &NotificationGroup{errs: make([]NotificationPeerErr, nerrs), workers: wk, retryCount: 3}
}

// WithNPeersThrottled returns a new NotificationGroup with length of errs slice upto nerrs,

		writeQuorum: quorum,
		errs:        make([]error, len(writers)),
	}

	for {
		var blocks [][]byte
		n, err := io.ReadFull(src, buf)
		if err != nil {
			if !IsErrIgnored(err, []error{
				io.EOF,
				io.ErrUnexpectedEOF,
			}...) {
				return 0, err
			}
		}

		eof := err == io.EOF || err == io.ErrUnexpectedEOF
		if n == 0 && total != 0 {
			// Reached EOF, nothing more to be done.
			break
		}

	// Merely for tracing storage
	path := ""
	if len(versions) > 0 {
		path = versions[0].Name
	}
	errs = make([]error, len(versions))
	ctx, done, err := p.TrackDiskHealth(ctx, storageMetricDeleteVersions, volume, path)
	if err != nil {
		for i := range errs {
			errs[i] = ctx.Err()
		}
		return errs
	}
	defer func() {

	deleteList := toNames(objectsToDelete)
	dObjects, errs := deleteObjectsFn(ctx, bucket, deleteList, ObjectOptions{
		PrefixEnabledFn:  vc.PrefixEnabled,
		VersionSuspended: vc.Suspended(),
	})

	// Are all objects saying bucket not found?
	if isAllBucketsNotFound(errs) {
		writeErrorResponse(ctx, w, toAPIError(ctx, errs[0]), r.URL)
		return
	}

	for i := range errs {

		}
		return ps
	}

	mkTest := func(N, parity, agree int) (res struct {
		metaArr  []FileInfo
		errs     []error
		parities []int
		parity   int
	},
	) {
		res.metaArr = mkMetaArr(N, parity, agree)
		res.parities = mkParities(N, N-(N/2+1), parity, agree)
		res.errs = make([]error, N)
		if agree >= N/2+1 { // simple majority consensus
			res.parity = N - (N/2 + 1)
		} else {

			meta, err := loadBucketMetadata(ctx, sys.objAPI, buckets[index])
			if err != nil {
				return err
			}
			bucketMetas[index] = meta
			return nil
		}, index)
	}

	errs := g.Wait()
	for index, err := range errs {
		if err != nil {
			internalLogOnceIf(ctx, fmt.Errorf("Unable to load bucket metadata, will be retried: %w", err),

			}
			return errFileCorrupt
		}, index)
	}

	// Wait for all the routines.
	mErrs := g.Wait()

	err := reduceWriteQuorumErrs(ctx, mErrs, objectOpIgnoredErrs, quorum)
	if err != nil && revert {
		ng := errgroup.WithNErrs(len(disks))
		for index := range disks {
			if mErrs[index] != nil {
				continue
			}
			index := index
			ng.Go(func() error {
				if disks[index] == nil {

		derrs[i] = checkDelObjArgs(ctx, bucket, objects[i].ObjectName)
		objSets.Add(objects[i].ObjectName)
	}

	// Acquire a bulk write lock across 'objects'
	multiDeleteLock := z.NewNSLock(bucket, objSets.ToSlice()...)
	lkctx, err := multiDeleteLock.GetLock(ctx, globalOperationTimeout)
	if err != nil {
		for i := range derrs {
			derrs[i] = err
		}
		return dobjects, derrs
	}