ipc/glue/ByteBuf.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 /* A type that can be sent without needing to make a copy during
   8  * serialization. In addition the receiver can take ownership of the
   9  * data to avoid having to make an additional copy. */
  10
  11 #ifndef mozilla_ipc_ByteBuf_h
  12 #define mozilla_ipc_ByteBuf_h
  13
  14 #include "mozilla/Assertions.h"
  15
  16 namespace IPC {
  17 template <typename T>
  18 struct ParamTraits;
  19 }
  20
  21 namespace mozilla {
  22
  23 namespace ipc {
  24
  25 class ByteBuf final {
  26   friend struct IPC::ParamTraits<mozilla::ipc::ByteBuf>;
  27
  28  public:
  29   bool Allocate(size_t aLength) {
  30     MOZ_ASSERT(mData == nullptr);
  31     mData = (uint8_t*)malloc(aLength);
  32     if (!mData) {
  33       return false;
  34     }
  35     mLen = aLength;
  36     mCapacity = aLength;
  37     return true;
  38   }
  39
  40   ByteBuf() : mData(nullptr), mLen(0), mCapacity(0) {}
  41
  42   ByteBuf(uint8_t* aData, size_t aLen, size_t aCapacity)
  43       : mData(aData), mLen(aLen), mCapacity(aCapacity) {}
  44
  45   ByteBuf(const ByteBuf& aFrom) = delete;
  46
  47   ByteBuf(ByteBuf&& aFrom)
  48       : mData(aFrom.mData), mLen(aFrom.mLen), mCapacity(aFrom.mCapacity) {
  49     aFrom.mData = nullptr;
  50     aFrom.mLen = 0;
  51     aFrom.mCapacity = 0;
  52   }
  53
  54   ByteBuf& operator=(ByteBuf&& aFrom) {
  55     std::swap(mData, aFrom.mData);
  56     std::swap(mLen, aFrom.mLen);
  57     std::swap(mCapacity, aFrom.mCapacity);
  58     return *this;
  59   }
  60
  61   ~ByteBuf() { free(mData); }
  62
  63   uint8_t* mData;
  64   size_t mLen;
  65   size_t mCapacity;
  66 };
  67
  68 }  // namespace ipc
  69 }  // namespace mozilla
  70
  71 #endif  // ifndef mozilla_ipc_ByteBuf_h