// An Update function must be set to provide an updated value when needed.
type Cache[T any] struct {
	// updateFn must return an updated value.
	// If an error is returned the cached value is not set.
	// Only one caller will call this function at any time, others will be blocking.
	// The returned value can no longer be modified once returned.
	// Should be set before calling Get().
	updateFn func() (T, error)

	// ttl for a cached value.

	select {
	case res := <-task.respCh:
		if !h.reportProgress {
			if errors.Is(res.err, errSkipFile) { // this is only sent usually by nopHeal
				return nil
			}

			// Report caller of any failure
			return res.err
		}
		res.result.Type = healType
		if res.err != nil {
			res.result.Detail = res.err.Error()
		}
		return h.pushHealResultItem(res.result)
	case <-h.ctx.Done():

// Assumes that c.Lock is held by caller.
func (c *iamCache) buildUserGroupMemberships() {
	for group, gi := range c.iamGroupsMap {
		c.updateGroupMembershipsMap(group, &gi)
	}
}

// updateGroupMembershipsMap - updates the memberships map for a
// group. IMPORTANT: Assumes c.Lock() is held by caller.
func (c *iamCache) updateGroupMembershipsMap(group string, gi *GroupInfo) {

		case objectlock.RetGovernance:
			// In governance mode, users can't overwrite or delete an object
			// version or alter its lock settings unless they have special
			// permissions. With governance mode, you protect objects against
			// being deleted by most users, but you can still grant some users
			// permission to alter the retention settings or delete the object
			// if necessary. You can also use governance mode to test retention-period

// Make sure to bump the internode version at storage-rest-common.go
type RawFileInfo struct {
	// Content of entire xl.meta (may contain data depending on what was requested by the caller.
	Buf []byte `msg:"b,allownil"`
}

// FileInfo - represents file stat information.
// The above means that any added/deleted fields are incompatible.

	return valid
}

// isTierNameInUse returns tier type and true if there exists a remote tier by
// name tierName, otherwise returns madmin.Unsupported and false. N B this
// function is meant for internal use, where the caller is expected to take
// appropriate locks.
func (config *TierConfigMgr) isTierNameInUse(tierName string) (madmin.TierType, bool) {
	if t, ok := config.Tiers[tierName]; ok {
		return t.Type, true
	}

		// side-channel check has failed, we shall take
		// the client offline in such situations.
		// generally all implementations should simply return
		// 403, but in situations where there is a dependency
		// with the caller to take the client offline purpose
		// fully it should make sure to respond with '412'
		// instead, see cmd/storage-rest-server.go for ideas.
		if c.HealthCheckFn != nil && resp.StatusCode == http.StatusPreconditionFailed {

		// transport is already down.
		return "", errDiskNotFound
	}

	// This call should never be over the network, this is always
	// a cached value - caller should make sure to use this
	// function on a fresh disk or make sure to look at the error
	// from a different networked call to validate the GetDiskID()
	return *client.diskID.Load(), nil
}

func (s *xlStorage) ReadAll(ctx context.Context, volume string, path string) (buf []byte, err error) {
	// Specific optimization to avoid re-read from the drives for `format.json`
	// in-case the caller is a network operation.
	if volume == minioMetaBucket && path == formatConfigFile {
		s.RLock()
		formatData := make([]byte, len(s.formatData))
		copy(formatData, s.formatData)
		s.RUnlock()

		}
	}()
	err = s.getStorage().ReadMultiple(r.Context(), req, responses)
	wg.Wait()
	rw.CloseWithError(err)
}

// globalLocalSetDrives is used for local drive as well as remote REST
// API caller for other nodes to talk to this node.
//
// Any updates to this must be serialized via globalLocalDrivesMu (locker)
var globalLocalSetDrives [][][]StorageAPI