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 #pragma once 17 18 #include <json/json.h> 19 #include <optional> 20 21 #include "common/libs/fs/shared_fd.h" 22 #include "common/libs/utils/result.h" 23 #include "host/commands/kernel_log_monitor/kernel_log_server.h" 24 25 namespace cuttlefish::monitor { 26 27 struct ReadEventResult { 28 Event event; 29 Json::Value metadata; 30 }; 31 32 // TODO(schuffelen): Remove `std::optional` if `socket_vsock_proxy` doesn't need 33 // this distinction. 34 /** Read a kernel log event from fd. A failed result indicates an error occurred 35 * while reading the event, while an empty optional indicates EOF. */ 36 Result<std::optional<ReadEventResult>> ReadEvent(SharedFD fd); 37 38 // Writes a kernel log event to the fd, in a format expected by ReadEvent. 39 bool WriteEvent(SharedFD fd, const Json::Value& event_message); 40 41 } // namespace cuttlefish::monitor 42