// are provided, we will not return bucket metrics.
			if bmg, ok := h.metricsData.bucketMGMap[collectorPath]; ok {
				if len(buckets) == 0 {
					continue
				}
				unLocker := bmg.LockAndSetBuckets(buckets)
				defer unLocker()
			}
			gatherers = append(gatherers, gatherer)
		}
	}

	if len(gatherers) == 0 {
		return notFoundHandler
	}

	return promhttp.HandlerFor(prometheus.Gatherers(gatherers), h.opts)

   * Returns a hash function implementing the Message Authentication Code (MAC) algorithm, using the
   * MD5 (128 hash bits) hash function and the given secret key.
   *
   * <p>If you are designing a new system that needs HMAC, prefer {@link #hmacSha256} or other
   * future-proof algorithms <a
   * href="https://datatracker.ietf.org/doc/html/rfc6151#section-2.3">over {@code hmacMd5}</a>.
   *
   * @param key the secret key

 * </ul>
 *
 * <p>When a test fails, the error message labels the objects involved in the failed comparison as
 * follows:
 *
 * <ul>
 *   <li>"{@code [group }<i>i</i>{@code , item }<i>j</i>{@code ]}" refers to the
 *       <i>j</i><sup>th</sup> item in the <i>i</i><sup>th</sup> equality group, where both equality
 *       groups and the items within equality groups are numbered starting from 1. When either a

# CORS (Cross-Origin Resource Sharing) { #cors-cross-origin-resource-sharing }

<a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS" class="external-link" target="_blank">CORS or "Cross-Origin Resource Sharing"</a> refers to the situations when a frontend running in a browser has JavaScript code that communicates with a backend, and the backend is in a different "origin" than the frontend.

## Origin { #origin }

func (m metacache) keepAlive(ctx context.Context, rpc *peerRESTClient) {
	// we intentionally operate on a copy of m, so we can update without locks.
	t := time.NewTicker(metacacheMaxClientWait / 10)
	defer t.Stop()
	for {
		select {
		case <-ctx.Done():
			// Request is done, stop updating.
			return
		case <-t.C:
			m.lastHandout = time.Now()

 *   </li>
 * <li>A hyphen usually precedes a qualifier, and is always less important than digits/number. For example
 *   {@code 1.0.RC2 < 1.0-RC3 < 1.0.1}; but prefer {@code 1.0.0-RC2} over {@code 1.0.0.RC2}, and more
 *   generally: {@code 1.0.X2 < 1.0-X3 < 1.0.1} for any string {@code X}; but prefer {@code 1.0.0-X1}
 *   over {@code 1.0.0.X1}.</li>
 * </ul>
 *

 * connection is typically faster than establishing a new one.
 *
 * When a single logical call requires multiple streams due to redirects or authorization
 * challenges, we prefer to use the same physical connection for all streams in the sequence. There
 * are potential performance and behavior consequences to this preference. To support this feature,

		}},
	}}

	for _, v := range vectors {
		t.Run(path.Base(v.file), func(t *testing.T) {
			f, err := os.Open(v.file)
			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}
			defer f.Close()

			var fr io.Reader = f
			if strings.HasSuffix(v.file, ".bz2") {
				fr = bzip2.NewReader(fr)
			}

			// Capture all headers and checksums.
			var (
				tr      = NewReader(fr)

With fast fallback, OkHttp attempts to connect to multiple web servers concurrently. It keeps whichever route connects first and cancels all of the others. Its rules are:

 * Prefer to alternate IP addresses from different address families, (IPv6 / IPv4), starting with IPv6.
 * Don't start a new attempt until 250 ms after the most recent attempt was started.

	lock := api.NewNSLock(r.Bucket, objInfo.Name)
	lkctx, err := lock.GetLock(ctx, globalOperationTimeout)
	if err != nil {
		return err
	}
	ctx = lkctx.Context()
	defer lock.Unlock(lkctx)

	opts := ObjectOptions{
		VersionID:        objInfo.VersionID,
		Versioned:        versioned,
		VersionSuspended: versionSuspended,
		NoLock:           true,
	}