}

// Parses signature version '4' query string of the following form.
//
//	querystring = X-Amz-Algorithm=algorithm
//	querystring += &X-Amz-Credential= urlencode(accessKey + '/' + credential_scope)
//	querystring += &X-Amz-Date=date
//	querystring += &X-Amz-Expires=timeout interval
//	querystring += &X-Amz-SignedHeaders=signed_headers
//	querystring += &X-Amz-Signature=signature
//

// must be extracted from the header.
var userMetadataKeyPrefixes = []string{
	"x-amz-meta-",
	"x-minio-meta-",
}

// extractMetadataFromReq extracts metadata from HTTP header and HTTP queryString.
func extractMetadataFromReq(ctx context.Context, r *http.Request) (metadata map[string]string, err error) {
	return extractMetadata(ctx, textproto.MIMEHeader(r.Form), textproto.MIMEHeader(r.Header))
}