netwerk/base/nsIContentSniffer.idl

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "nsISupports.idl"
   6
   7 interface nsIRequest;
   8
   9 /**
  10  * Content sniffer interface. Components implementing this interface can
  11  * determine a MIME type from a chunk of bytes.
  12  */
  13 [scriptable, uuid(a5772d1b-fc63-495e-a169-96e8d3311af0)]
  14 interface nsIContentSniffer : nsISupports
  15 {
  16   /**
  17    * Given a chunk of data, determines a MIME type. Information from the given
  18    * request may be used in order to make a better decision.
  19    *
  20    * @param aRequest The request where this data came from. May be null.
  21    * @param aData Data to check
  22    * @param aLength Length of the data
  23    *
  24    * @return The content type
  25    *
  26    * @throw NS_ERROR_NOT_AVAILABLE if no MIME type could be determined.
  27    *
  28    * @note Implementations should consider the request read-only. Especially,
  29    * they should not attempt to set the content type property that subclasses of
  30    * nsIRequest might offer.
  31    */
  32   ACString getMIMETypeFromContent(in nsIRequest aRequest,
  33                                   [const,array,size_is(aLength)] in octet aData,
  34                                   in unsigned long aLength);
  35 };