var prefixUsageCache = cachevalue.New[map[string]uint64]()

// loadPrefixUsageFromBackend returns prefix usages found in passed buckets
//
//	e.g.:  /testbucket/prefix => 355601334
func loadPrefixUsageFromBackend(ctx context.Context, objAPI ObjectLayer, bucket string) (map[string]uint64, error) {
	z, ok := objAPI.(*erasureServerPools)
	if !ok {
		// Prefix usage is empty
		return map[string]uint64{}, nil
	}

	cache := dataUsageCache{}

		return nil
	}

	var (
		clusterSize               uint64
		clusterBuckets            uint64
		clusterObjectsCount       uint64
		clusterVersionsCount      uint64
		clusterDeleteMarkersCount uint64
	)

	clusterObjectSizesHistogram := map[string]uint64{}
	clusterVersionsHistogram := map[string]uint64{}
	for _, usage := range dataUsageInfo.BucketsUsage {
		clusterBuckets++

		if uint64(size) >= quotaSize { // check if file size already exceeds the quota
			return BucketQuotaExceeded{Bucket: bucket}
		}

		bui := sys.GetBucketUsageInfo(ctx, bucket)
		if bui.Size > 0 && ((bui.Size + uint64(size)) >= quotaSize) {
			return BucketQuotaExceeded{Bucket: bucket}
		}
	}

	return nil
}

func enforceBucketQuotaHard(ctx context.Context, bucket string, size int64) error {

	debug bool
}

type sizeSummary struct {
	totalSize       int64
	versions        uint64
	deleteMarkers   uint64
	replicatedSize  int64
	replicatedCount int64
	pendingSize     int64
	failedSize      int64
	replicaSize     int64
	replicaCount    int64
	pendingCount    uint64
	failedCount     uint64
	replTargetStats map[string]replTargetSizeSummary
	tiers           map[string]tierStats
}

func reduceCommonVersions(diskVersions [][]byte, writeQuorum int) (versions []byte) {
	diskVersionsCount := make(map[uint64]int)
	for _, versions := range diskVersions {
		if len(versions) > 0 {
			diskVersionsCount[binary.BigEndian.Uint64(versions)]++
		}
	}

	var commonVersions uint64
	maxCnt := 0
	for versions, count := range diskVersionsCount {
		if maxCnt < count {
			maxCnt = count

//
// The above means that any added/deleted fields are incompatible.
//
//msgp:tuple DiskInfo
type DiskInfo struct {
	Total      uint64
	Free       uint64
	Used       uint64
	UsedInodes uint64
	FreeInodes uint64
	Major      uint32
	Minor      uint32
	NRRequests uint64
	FSType     string
	RootDisk   bool
	Healing    bool
	Scanning   bool
	Endpoint   string
	MountPath  string
	ID         string

	rv := reflect.ValueOf(fieldValue)
	switch v := fieldValue.(type) {
	case int64, int, uint, uint64, int32, uint32, int16, uint16:
		result = time.Unix(reflect.Indirect(rv).Int(), 0).UTC()
	case *int64, *int, *uint, *uint64, *int32, *uint32, *int16, *uint16:
		if rv.IsZero() {
			return nil, nil
		}
		result = time.Unix(reflect.Indirect(rv).Int(), 0).UTC()
	default:

// hashDeterministicString will return a deterministic hash for the map values.
// Trivial collisions are avoided, but this is by no means a strong hash.
func hashDeterministicString(m map[string]string) uint64 {
	// Seed (random)
	crc := uint64(0xc2b40bbac11a7295)
	// Xor each value to make order independent
	for k, v := range m {
		// Separate key and value with an individual xor with a random number.

	totalWrites           atomic.Uint64
	totalDeletes          atomic.Uint64
	totalErrsAvailability atomic.Uint64 // Captures all data availability errors such as faulty disk, timeout errors.
	totalErrsTimeout      atomic.Uint64 // Captures all timeout only errors

	// apiCalls should be placed first so alignment is guaranteed for atomic operations.
	apiCalls     [storageMetricLast]uint64

		content          []byte
		method           uint16
		flags            uint16
		crc32            uint32
		uncompressedSize uint64
		compressedSize   uint64
	}{
		{
			name:    "small store w desc",
			content: []byte("gophers"),
			method:  Store,
			flags:   0x8,
		},
		{
			name:    "small deflate wo desc",
			content: bytes.Repeat([]byte("abcdefg"), 2048),
			method:  Deflate,
		},