ipc/glue/IPCStreamUtils.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_ipc_IPCStreamUtils_h
   8 #define mozilla_ipc_IPCStreamUtils_h
   9
  10 #include "mozilla/ipc/IPCStream.h"
  11 #include "nsCOMPtr.h"
  12 #include "nsIInputStream.h"
  13
  14 namespace mozilla::ipc {
  15
  16 // Serialize an IPCStream to be sent over IPC fallibly.
  17 //
  18 // If |aAllowLazy| is true the stream may be serialized as a
  19 // RemoteLazyInputStream when being sent from child to parent.
  20 //
  21 // ParamTraits<nsIInputStream> may be used instead if serialization cannot be
  22 // fallible.
  23 [[nodiscard]] bool SerializeIPCStream(
  24     already_AddRefed<nsIInputStream> aInputStream, IPCStream& aValue,
  25     bool aAllowLazy);
  26
  27 // If serialization fails, `aValue` will be initialized to `Nothing()`, so this
  28 // return value is safe to ignore.
  29 bool SerializeIPCStream(already_AddRefed<nsIInputStream> aInputStream,
  30                         Maybe<IPCStream>& aValue, bool aAllowLazy);
  31
  32 // Deserialize an IPCStream received from an actor call.  These methods
  33 // work in both the child and parent.
  34 already_AddRefed<nsIInputStream> DeserializeIPCStream(const IPCStream& aValue);
  35
  36 already_AddRefed<nsIInputStream> DeserializeIPCStream(
  37     const Maybe<IPCStream>& aValue);
  38
  39 }  // namespace mozilla::ipc
  40
  41 namespace IPC {
  42
  43 template <>
  44 struct ParamTraits<nsIInputStream*> {
  45   static void Write(MessageWriter* aWriter, nsIInputStream* aParam);
  46   static bool Read(MessageReader* aReader, RefPtr<nsIInputStream>* aResult);
  47 };
  48
  49 }  // namespace IPC
  50
  51 #endif  // mozilla_ipc_IPCStreamUtils_h