xpcom/io/nsICloneableInputStream.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 "nsIInputStream.idl"
   6
   7 [scriptable, builtinclass, uuid(8149be1f-44d3-4f14-8b65-a57a5fbbeb97)]
   8 interface nsICloneableInputStream : nsISupports
   9 {
  10   // Allow streams that implement the interface to determine if cloning
  11   // possible at runtime.  For example, this allows wrappers to check if
  12   // their base stream supports cloning.
  13   [infallible] readonly attribute boolean cloneable;
  14
  15   // Produce a copy of the current stream in the most efficient way possible.
  16   // In this case "copy" means that both the original and cloned streams
  17   // should produce the same bytes for all future reads.  Bytes that have
  18   // already been consumed from the original stream are not copied to the
  19   // clone.  Operations on the two streams should be completely independent
  20   // after the clone() occurs.
  21   nsIInputStream clone();
  22 };
  23
  24 // This interface implements cloneWithRange() because for some streams
  25 // (IPCBlobInputStream only, so far) are more efficient to produce a sub
  26 // stream with range than doing clone + SlicedInputStream().
  27 [scriptable, builtinclass, uuid(ece853c3-aded-4cef-8f51-0d1493d60bd5)]
  28 interface nsICloneableInputStreamWithRange : nsICloneableInputStream
  29 {
  30   nsIInputStream cloneWithRange(in uint64_t start, in uint64_t length);
  31 };