dst = append(dst, pre) // Only add non-empty fragments
		}
		pre.Offset = cur.endOffset()
	}
	pre.Length = size - pre.Offset // Possibly the only empty fragment
	return append(dst, pre)
}

// fileState tracks the number of logical (includes sparse holes) and physical
// (actual in tar archive) bytes remaining for the current file.
//
// Invariant: logicalRemaining >= physicalRemaining
type fileState interface {

	ObjectV2         *xlMetaV2Object       `json:"V2Obj,omitempty" msg:"V2Obj,omitempty"`
	DeleteMarker     *xlMetaV2DeleteMarker `json:"DelObj,omitempty" msg:"DelObj,omitempty"`
	WrittenByVersion uint64                `msg:"v"` // Tracks written by MinIO version
}

// xlFlags contains flags on the object.
// This can be extended up to 64 bits without breaking compatibility.
type xlFlags uint8

const (
	xlFlagFreeVersion xlFlags = 1 << iota

	}

	name := env.Get(EnvSiteName, siteKV.Get(NameKey))
	if name != "" {
		if !validSiteNameRegex.MatchString(name) {
			err = Errorf(
				"site name '%s' is invalid, expected simple characters such as [cal-rack0, myname...]",
				name)
			return
		}
		s.Name = name
	}
	return
}

// CheckValidKeys - checks if inputs KVS has the necessary keys,
// returns error if it find extra or superfluous keys.

// It also handles incoming requests and routes them to the appropriate connection.
type Manager struct {
	// ID is an instance ID, that will change whenever the server restarts.
	// This allows remotes to keep track of whether state is preserved.
	ID uuid.UUID

	// Immutable after creation, so no locks.
	targets map[string]*Connection

	// serverside handlers.
	handlers handlers

	// local host name.
	local string

	go func(o listPathOptions) {
		err := z.listMerged(listCtx, o, inCh)
		if err != nil {
			meta.setErr(err.Error())
		}
		o.debugln("listAndSave: listing", o.ID, "finished with ", err)
	}(*o)

	// Keep track of when we return since we no longer have to send entries to output.
	var funcReturned bool
	var funcReturnedMu sync.Mutex
	defer func() {
		funcReturnedMu.Lock()
		funcReturned = true
		funcReturnedMu.Unlock()

	_         int32 // For 64 bits alignment
	lastConn  int64

	// HealthCheckFn is the function set to test for health.
	// If not set the client will not keep track of health.
	// Calling this returns true or false if the target
	// is online or offline.
	HealthCheckFn func() bool

	// HealthCheckRetryUnit will be used to calculate the exponential

		// Clean up the common prefixes
		file = trimTrace(file)
		// Get the function name
		_, funcName := filepath.Split(runtime.FuncForPC(pc).Name())
		// Skip duplicate traces that start with file name, "<autogenerated>"
		// and also skip traces with function name that starts with "runtime."
		if !strings.HasPrefix(file, "<autogenerated>") &&
			!strings.HasPrefix(funcName, "runtime.") {

			failOnErr(err)
			encoded, err := e.EncodeData(GlobalContext, testData[:])
			failOnErr(err)
			hash := xxhash.New()
			for i, data := range encoded {
				// Write index to keep track of sizes of each.
				_, err = hash.Write([]byte{byte(i)})
				failOnErr(err)
				_, err = hash.Write(data)
				failOnErr(err)
				got[conf] = map[ErasureAlgo]uint64{algo: hash.Sum64()}
			}

	// suspended or disabled on this bucket. RenameData will replace
	// the 'null' version. We add a free-version to track its tiered
	// content for asynchronous deletion.
	//
	// Note: RestoreObject and HealObject requests don't end up replacing the
	// null version and therefore don't require the free-version to track
	// anything
	if fi.VersionID == "" && !fi.IsRestoreObjReq() && !fi.Healing() {

	}
}

type currentPathTracker struct {
	name *unsafe.Pointer // contains atomically accessed *string
}

// currentPathUpdater provides a lightweight update function for keeping track of
// current objects for each disk.
// Returns a function that can be used to update the current object
// and a function to call to when processing finished.