xpcom/io/nsITellableStream.idl

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6
   7 /*
   8  * nsITellableStream
   9  *
  10  * This class is separate from nsISeekableStream in order to let streams to
  11  * implement ::Tell() without implementing the whole nsISeekableStream
  12  * interface. Callers can QI the stream to know what is implemented. This is
  13  * mainly done for nsPipeInputStream.
  14  *
  15  *
  16  * Implementing this interface, streams are able to expose the current offset
  17  * via ::tell().
  18  */
  19
  20 #include "nsISupports.idl"
  21
  22 [scriptable, uuid(ee942946-4538-45d2-bf05-ffdbf5932621)]
  23 interface nsITellableStream : nsISupports
  24 {
  25     /**
  26      *  tell
  27      *
  28      *  This method reports the current offset, in bytes, from the start of the
  29      *  stream.
  30      *
  31      *   @throws NS_BASE_STREAM_CLOSED if called on a closed stream.
  32      */
  33     long long tell();
  34 };