ipc/glue/RustMessageUtils.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   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 #ifndef mozilla_ipc_RustMessageUtils_h
   7 #define mozilla_ipc_RustMessageUtils_h
   8
   9 #include "chrome/common/ipc_message_utils.h"
  10
  11 // Some macros for rust integrations. See ipc/rust/ipdl_utils
  12 #define MOZ_DEFINE_RUST_PARAMTRAITS(type_, serializer_, deserializer_)        \
  13   extern "C" uint8_t* serializer_(const type_*, size_t* len, size_t* cap);    \
  14   extern "C" bool deserializer_(const uint8_t*, size_t len, type_*);          \
  15                                                                               \
  16   template <>                                                                 \
  17   struct IPC::ParamTraits<type_> {                                            \
  18     using paramType = type_;                                                  \
  19     static void Write(IPC::MessageWriter* aWriter, const paramType& aParam) { \
  20       size_t len, cap;                                                        \
  21       uint8_t* buf = serializer_(&aParam, &cap, &len);                        \
  22       MOZ_DIAGNOSTIC_ASSERT(buf, #type_ " serialization failed");             \
  23       WriteParam(aWriter, mozilla::ipc::ByteBuf(buf, len, cap));              \
  24     }                                                                         \
  25     static IPC::ReadResult<paramType> Read(IPC::MessageReader* aReader) {     \
  26       mozilla::ipc::ByteBuf in;                                               \
  27       IPC::ReadResult<paramType> result;                                      \
  28       if (!ReadParam(aReader, &in) || !in.mData) {                            \
  29         return result;                                                        \
  30       }                                                                       \
  31       /* TODO: Should be able to initialize `result` in-place instead */      \
  32       mozilla::AlignedStorage2<paramType> value;                              \
  33       if (!deserializer_(in.mData, in.mLen, value.addr())) {                  \
  34         return result;                                                        \
  35       }                                                                       \
  36       result = std::move(*value.addr());                                      \
  37       value.addr()->~paramType();                                             \
  38       return result;                                                          \
  39     }                                                                         \
  40   };
  41
  42 #endif