1 /* 2 * Copyright (C) 2020 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef INCLUDE_PERFETTO_PROTOZERO_ROOT_MESSAGE_H_ 18 #define INCLUDE_PERFETTO_PROTOZERO_ROOT_MESSAGE_H_ 19 20 #include "perfetto/protozero/message.h" 21 #include "perfetto/protozero/message_arena.h" 22 23 namespace protozero { 24 25 // Helper class to hand out messages using the default MessageArena. 26 // Usage: 27 // RootMessage<perfetto::protos::zero::MyMessage> msg; 28 // msg.Reset(stream_writer); 29 // msg.set_foo(...); 30 // auto* nested = msg.set_nested(); 31 template <typename T = Message> 32 class RootMessage : public T { 33 public: RootMessage()34 RootMessage() { T::Reset(nullptr, &root_arena_); } 35 36 // Disallow copy and move. 37 RootMessage(const RootMessage&) = delete; 38 RootMessage& operator=(const RootMessage&) = delete; 39 RootMessage(RootMessage&&) = delete; 40 RootMessage& operator=(RootMessage&&) = delete; 41 Reset(ScatteredStreamWriter * writer)42 void Reset(ScatteredStreamWriter* writer) { 43 root_arena_.Reset(); 44 Message::Reset(writer, &root_arena_); 45 } 46 47 private: 48 MessageArena root_arena_; 49 }; 50 51 } // namespace protozero 52 53 #endif // INCLUDE_PERFETTO_PROTOZERO_ROOT_MESSAGE_H_ 54