// -----------
// The HEAD operation retrieves metadata from an object without returning the object itself.
func (api objectAPIHandlers) HeadObjectHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "HeadObject")
	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))

	objectAPI := api.ObjectAPI()
	if objectAPI == nil {
		writeErrorResponseHeadersOnly(w, errorCodes.ToAPIErr(ErrServerNotInitialized))
		return

		// Verify if the dataDir is present or not when the data
		// is not inlined to make sure we return correct errors
		// during HeadObject().

		// Healing must not come here and return error, since healing
		// deals with dataDirs directly, let healing fix things automatically.
		if lerr := Access(pathJoin(volumeDir, path, fi.DataDir)); lerr != nil {

			t := router.Methods(r.methods...).
				HandlerFunc(collectAPIStats(r.api, httpTraceAll(notImplementedHandler))).
				Queries(r.queries...)
			t.Path(r.path)
		}

		// Object operations
		// HeadObject
		router.Methods(http.MethodHead).Path("/{object:.+}").
			HandlerFunc(s3APIMiddleware(api.HeadObjectHandler))

		// GetObjectAttributes
		router.Methods(http.MethodGet).Path("/{object:.+}").

		case "PostPolicy":
			// Register PostPolicy handler.
			bucket.Methods(http.MethodPost).HeadersRegexp("Content-Type", "multipart/form-data*").HandlerFunc(api.PostPolicyBucketHandler)
		case "HeadObject":
			// Register HeadObject handler.
			bucket.Methods("Head").Path("/{object:.+}").HandlerFunc(api.HeadObjectHandler)
		case "GetObject":
			// Register GetObject handler.

	PartNumber          int                 // only useful in case of GetObject/HeadObject
	CheckPrecondFn      CheckPreconditionFn // only set during GetObject/HeadObject/CopyObjectPart preconditional valuation
	EvalMetadataFn      EvalMetadataFn      // only set for retention settings, meant to be used only when updating metadata in-place.

- Range requests for GetObject/HeadObject for individual files from zip is not supported.
- Names inside ZIP files are kept unmodified, but some may lead to invalid paths. See [Object key naming guidelines](https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-keys.html) on safe names.
- This API behavior is limited for following **read** operations on files inside a zip archive:
  - `HeadObject`
  - `GetObject`
  - `ListObjectsV2`

	}

	if objInfo.IsRemote() {
		// Check if object is being restored. For more information on x-amz-restore header see
		// https://docs.aws.amazon.com/AmazonS3/latest/API/API_HeadObject.html#API_HeadObject_ResponseSyntax
		w.Header()[xhttp.AmzStorageClass] = []string{objInfo.TransitionedObject.Tier}
	}

	if lc, err := globalLifecycleSys.Get(objInfo.Bucket); err == nil {

const (
	putObjectTaggingAPI    replProxyAPI = "PutObjectTagging"
	getObjectTaggingAPI    replProxyAPI = "GetObjectTagging"
	removeObjectTaggingAPI replProxyAPI = "RemoveObjectTagging"
	headObjectAPI          replProxyAPI = "HeadObject"
	getObjectAPI           replProxyAPI = "GetObject"
)

// ProxyMetric holds stats for replication proxying
type ProxyMetric struct {
	PutTagTotal       uint64 `json:"putTaggingProxyTotal" msg:"ptc"`

	TooBigObject
	TooBigDecodedLength
	BadSignature
	BadMD5
	MissingUploadID
)

// Wrapper for calling HeadObject API handler tests for both Erasure multiple disks and FS single drive setup.
func TestAPIHeadObjectHandler(t *testing.T) {
	ExecObjectLayerAPITest(t, testAPIHeadObjectHandler, []string{"HeadObject"})
}

func testAPIHeadObjectHandler(obj ObjectLayer, instanceType, bucketName string, apiRouter http.Handler,