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 <atomic>
20 #include <bitset>
21 #include <list>
22 #include <mutex>
23 #include <queue>
24 #include <thread>
25 #include <vector>
26 
27 #include <android-base/thread_annotations.h>
28 
29 #include "LogBuffer.h"
30 #include "LogReaderList.h"
31 #include "LogStatistics.h"
32 #include "LogTags.h"
33 #include "LogdLock.h"
34 #include "SerializedLogChunk.h"
35 #include "SerializedLogEntry.h"
36 
37 class SerializedLogBuffer final : public LogBuffer {
38   public:
39     // Create SerializedLogChunk's with size = max_size_[log_id] / kChunkSizeDivisor.
40     static constexpr size_t kChunkSizeDivisor = 4;
41 
42     SerializedLogBuffer(LogReaderList* reader_list, LogTags* tags, LogStatistics* stats);
43     void Init() override;
44 
45     int Log(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid, pid_t tid, const char* msg,
46             uint16_t len) override;
47     std::unique_ptr<FlushToState> CreateFlushToState(uint64_t start, LogMask log_mask)
48             REQUIRES(logd_lock) override;
49     bool FlushTo(LogWriter* writer, FlushToState& state,
50                  const std::function<FilterResult(log_id_t log_id, pid_t pid, uint64_t sequence,
51                                                   log_time realtime)>& filter)
52             REQUIRES(logd_lock) override;
53 
54     bool Clear(log_id_t id, uid_t uid) override;
55     size_t GetSize(log_id_t id) override;
56     bool SetSize(log_id_t id, size_t size) override;
57 
sequence()58     uint64_t sequence() const override { return sequence_.load(std::memory_order_relaxed); }
59 
60   private:
61     bool ShouldLog(log_id_t log_id, const char* msg, uint16_t len);
62     void MaybePrune(log_id_t log_id) REQUIRES(logd_lock);
63     void Prune(log_id_t log_id, size_t bytes_to_free) REQUIRES(logd_lock);
64     void UidClear(log_id_t log_id, uid_t uid) REQUIRES(logd_lock);
65     void RemoveChunkFromStats(log_id_t log_id, SerializedLogChunk& chunk);
66     size_t GetSizeUsed(log_id_t id) REQUIRES(logd_lock);
67 
68     LogReaderList* reader_list_;
69     LogTags* tags_;
70     LogStatistics* stats_;
71 
72     size_t max_size_[LOG_ID_MAX] GUARDED_BY(logd_lock) = {};
73     std::list<SerializedLogChunk> logs_[LOG_ID_MAX] GUARDED_BY(logd_lock);
74 
75     std::atomic<uint64_t> sequence_ = 1;
76 };
77 
78 // Exposed for testing.
79 void ClearLogsByUid(std::list<SerializedLogChunk>& log_buffer, uid_t uid, size_t max_size,
80                     log_id_t log_id, LogStatistics* stats);