// `.TnitOnce`.
func New[T any]() *Cache[T] {
	return &Cache[T]{}
}

// NewFromFunc allocates a new cached value instance and initializes it with an
// update function, making it ready for use.
func NewFromFunc[T any](ttl time.Duration, opts Opts, update func() (T, error)) *Cache[T] {
	return &Cache[T]{
		ttl:      ttl,
		updateFn: update,
		opts:     opts,
	}
}

}

const metacacheMaxEntries = 5000

// initManager will start async saving the cache.
func (m *metacacheManager) initManager() {
	// Add a transient bucket.
	// Start saver when object layer is ready.
	go func() {
		objAPI := newObjectLayerFn()
		for objAPI == nil {
			time.Sleep(time.Second)
			objAPI = newObjectLayerFn()
		}

		t := time.NewTicker(time.Minute)
		defer t.Stop()

		var exit bool

		}
		ctx = lkctx.Context()

		// Release lock when the metadata is verified, and reader
		// is ready to be read.
		//
		// This is possible to be lock free because
		// - xl.meta for inlined objects has already read the data
		//   into memory, any mutation on xl.meta subsequently is
		//   inconsequential to the overall read operation.
		// - xl.meta metadata is still verified for quorum under lock()

		HTTPStatusCode: http.StatusServiceUnavailable,
	},
	ErrClientDisconnected: {
		Code:           "ClientDisconnected",
		Description:    "Client disconnected before response was ready",
		HTTPStatusCode: 499, // No official code, use nginx value.
	},
	ErrTooManyRequests: {
		Code:           "TooManyRequests",

	EnvAPIObjectMaxVersions           = "MINIO_API_OBJECT_MAX_VERSIONS"
	EnvAPIObjectMaxVersionsLegacy     = "_MINIO_OBJECT_MAX_VERSIONS"
)

// Deprecated key and ENVs
const (
	apiReadyDeadline            = "ready_deadline"
	apiReplicationWorkers       = "replication_workers"
	apiReplicationFailedWorkers = "replication_failed_workers"
)

// DefaultKVS - default storage class config
var (
	DefaultKVS = config.KVS{

				"X-Amz-Date":           now.Format(iso8601Format),
				"X-Amz-Content-Sha256": payloadSHA256,
			},
			region:   region,
			expected: ErrSignatureDoesNotMatch,
		},
		// (6) Should error if the request is not ready yet, ie X-Amz-Date is in the future.
		{
			queryParams: map[string]string{
				"X-Amz-Algorithm":      signV4Algorithm,
				"X-Amz-Date":           now.Add(1 * time.Hour).Format(iso8601Format),

}

// readMultipleFiles Reads raw data from all specified files from all disks.
func readMultipleFiles(ctx context.Context, disks []StorageAPI, req ReadMultipleReq, readQuorum int) ([]ReadMultipleResp, error) {
	resps := make([]chan ReadMultipleResp, len(disks))
	for i := range resps {
		resps[i] = make(chan ReadMultipleResp, len(req.Files))
	}
	g := errgroup.WithNErrs(len(disks))
	// Read files in parallel across disks.

	prefixAll  string
}

// disconnectReader will ensure that no reads can take place on
// the upstream reader after close has been called.
type disconnectReader struct {
	r  io.Reader
	mu sync.Mutex
}

func (d *disconnectReader) Read(p []byte) (n int, err error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	if d.r != nil {
		return d.r.Read(p)
	}
	return 0, errors.New("reader closed")
}

	return NewChecksumWithType(NewChecksumType(alg), value)
}

// AppendTo will append the checksum to b.
// 'parts' is used when checksum has ChecksumMultipart set.
// ReadCheckSums reads the values back.
func (c *Checksum) AppendTo(b []byte, parts []byte) []byte {
	if c == nil {
		return nil
	}
	var tmp [binary.MaxVarintLen32]byte
	n := binary.PutUvarint(tmp[:], uint64(c.Type))
	crc := c.Raw

		up -d --build

	add_alias

	mc mb minio/minio-test/
	mc cp ./minio minio/minio-test/to-read/
	mc cp /etc/hosts minio/minio-test/to-read/hosts
	mc anonymous set download minio/minio-test

	verify_checksum_mc ./minio minio/minio-test/to-read/minio

	curl -s http://127.0.0.1:9000/minio-test/to-read/hosts | sha256sum

	MINIO_VERSION=dev docker-compose -f "buildscripts/upgrade-tests/compose.yml" stop
}