}

// IsHSTSIncludeSubdomains - is HSTS 'includeSubdomains' directive enabled
func (browseCfg *Config) IsHSTSIncludeSubdomains() string {
	configLock.RLock()
	defer configLock.RUnlock()
	if browseCfg.HSTSSeconds > 0 && browseCfg.HSTSIncludeSubdomains {
		return config.EnableOn
	}
	return config.EnableOff
}

// IsHSTSPreload - is HSTS 'preload' directive enabled
func (browseCfg *Config) IsHSTSPreload() string {

	// Storage class is special, it can be replaced regardless of the
	// metadata directive, if set should be preserved and replaced
	// to the destination metadata.
	sc := r.Header.Get(xhttp.AmzStorageClass)
	if sc == "" {
		sc = r.Form.Get(xhttp.AmzStorageClass)
	}

	// if x-amz-metadata-directive says REPLACE then
	// we extract metadata from the input headers.

		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidMetadataDirective: {
		Code:           "InvalidArgument",
		Description:    "Unknown metadata directive.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrInvalidStorageClass: {
		Code:           "InvalidStorageClass",
		Description:    "Invalid storage class.",
		HTTPStatusCode: http.StatusBadRequest,
	},

}

// isDirectiveValid - check if tagging-directive is valid.
func isDirectiveValid(v string) bool {
	// Check if set metadata-directive is valid.
	return isDirectiveCopy(v) || isDirectiveReplace(v)
}

// Check if the directive COPY is requested.
func isDirectiveCopy(value string) bool {
	// By default if directive is not set we
	// treat it as 'COPY' this function returns true.

	if err = checkPathLength(filePath); err != nil {
		return err
	}

	flags := os.O_CREATE | os.O_WRONLY | os.O_TRUNC

	var w *os.File
	if sync {
		// Perform DirectIO along with fdatasync for larger xl.meta, mostly when
		// xl.meta has "inlined data" we prefer writing O_DIRECT and then doing
		// fdatasync() at the end instead of opening the file with O_DSYNC.
		//

	StreamHandlerFn func(ctx context.Context, payload []byte, in <-chan []byte, out chan<- []byte) *RemoteErr

	// StreamHandler handles fully bidirectional streams,
	// There is flow control in both directions.
	StreamHandler struct {
		// Handle an incoming request. Initial payload is sent.
		// Additional input packets (if any) are streamed to request.
		// Upstream will block when request channel is full.

   See the License for the specific language governing permissions and
   limitations under the License.
================================================================

github.com/ncw/directio
https://github.com/ncw/directio
----------------------------------------------------------------
Copyright (C) 2012 by Nick Craig-Wood http://www.craig-wood.com/nick/

}

func setBrowserRedirectMiddleware(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		read := r.Method == http.MethodGet || r.Method == http.MethodHead
		// Re-direction is handled specifically for browser requests.
		if !guessIsHealthCheckReq(r) && guessIsBrowserReq(r) && read && globalBrowserRedirect {
			// Fetch the redirect location if any.
			if u := getRedirectLocation(r); u != nil {

	ErrPastObjectLockRetainDate = errors.New("the retain until date must be in the future")
	// ErrUnknownWORMModeDirective - indicates that the retention mode is invalid
	ErrUnknownWORMModeDirective = errors.New("unknown WORM mode directive")
	// ErrObjectLockMissingContentMD5 - indicates missing Content-MD5 header for put object requests with locking

	if !fi1.ModTime().Equal(fi2.ModTime()) {
		return false
	}
	if fi1.Mode() != fi2.Mode() {
		return false
	}
	return fi1.Size() == fi2.Size()
}

// DirectioAlignSize - DirectIO alignment needs to be 4K. Defined here as
// directio.AlignSize is defined as 0 in MacOS causing divide by 0 error.
const DirectioAlignSize = 4096

// CopyAligned - copies from reader to writer using the aligned input