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 #pragma once 18 19 #include <sys/types.h> 20 21 #include <functional> 22 #include <memory> 23 24 #include <android-base/thread_annotations.h> 25 #include <log/log.h> 26 #include <log/log_read.h> 27 28 #include "LogWriter.h" 29 #include "LogdLock.h" 30 31 // A mask to represent which log buffers a reader is watching, values are (1 << LOG_ID_MAIN), etc. 32 using LogMask = uint32_t; 33 constexpr uint32_t kLogMaskAll = 0xFFFFFFFF; 34 35 // State that a LogBuffer may want to persist across calls to FlushTo(). 36 class FlushToState { 37 public: FlushToState(uint64_t start,LogMask log_mask)38 FlushToState(uint64_t start, LogMask log_mask) : start_(start), log_mask_(log_mask) {} ~FlushToState()39 virtual ~FlushToState() {} 40 start()41 uint64_t start() const { return start_; } set_start(uint64_t start)42 void set_start(uint64_t start) { start_ = start; } 43 log_mask()44 LogMask log_mask() const { return log_mask_; } 45 46 private: 47 uint64_t start_; 48 LogMask log_mask_; 49 }; 50 51 // Enum for the return values of the `filter` function passed to FlushTo(). 52 enum class FilterResult { 53 kSkip, 54 kStop, 55 kWrite, 56 }; 57 58 class LogBuffer { 59 public: ~LogBuffer()60 virtual ~LogBuffer() {} 61 62 virtual void Init() = 0; 63 64 virtual int Log(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid, pid_t tid, 65 const char* msg, uint16_t len) = 0; 66 67 virtual std::unique_ptr<FlushToState> CreateFlushToState(uint64_t start, LogMask log_mask) 68 REQUIRES(logd_lock) = 0; 69 virtual bool FlushTo( 70 LogWriter* writer, FlushToState& state, 71 const std::function<FilterResult(log_id_t log_id, pid_t pid, uint64_t sequence, 72 log_time realtime)>& filter) REQUIRES(logd_lock) = 0; 73 74 virtual bool Clear(log_id_t id, uid_t uid) = 0; 75 virtual size_t GetSize(log_id_t id) = 0; 76 virtual bool SetSize(log_id_t id, size_t size) = 0; 77 78 virtual uint64_t sequence() const = 0; 79 }; 80