xref: /aosp_15_r20/system/logging/logd/SimpleLogBuffer.h (revision 598139dc91b21518d67c408eaea2644226490971)
1*598139dcSAndroid Build Coastguard Worker /*
2*598139dcSAndroid Build Coastguard Worker  * Copyright (C) 2020 The Android Open Source Project
3*598139dcSAndroid Build Coastguard Worker  *
4*598139dcSAndroid Build Coastguard Worker  * Licensed under the Apache License, Version 2.0 (the "License");
5*598139dcSAndroid Build Coastguard Worker  * you may not use this file except in compliance with the License.
6*598139dcSAndroid Build Coastguard Worker  * You may obtain a copy of the License at
7*598139dcSAndroid Build Coastguard Worker  *
8*598139dcSAndroid Build Coastguard Worker  *      http://www.apache.org/licenses/LICENSE-2.0
9*598139dcSAndroid Build Coastguard Worker  *
10*598139dcSAndroid Build Coastguard Worker  * Unless required by applicable law or agreed to in writing, software
11*598139dcSAndroid Build Coastguard Worker  * distributed under the License is distributed on an "AS IS" BASIS,
12*598139dcSAndroid Build Coastguard Worker  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13*598139dcSAndroid Build Coastguard Worker  * See the License for the specific language governing permissions and
14*598139dcSAndroid Build Coastguard Worker  * limitations under the License.
15*598139dcSAndroid Build Coastguard Worker  */
16*598139dcSAndroid Build Coastguard Worker 
17*598139dcSAndroid Build Coastguard Worker #pragma once
18*598139dcSAndroid Build Coastguard Worker 
19*598139dcSAndroid Build Coastguard Worker #include <atomic>
20*598139dcSAndroid Build Coastguard Worker #include <list>
21*598139dcSAndroid Build Coastguard Worker #include <mutex>
22*598139dcSAndroid Build Coastguard Worker 
23*598139dcSAndroid Build Coastguard Worker #include "LogBuffer.h"
24*598139dcSAndroid Build Coastguard Worker #include "LogBufferElement.h"
25*598139dcSAndroid Build Coastguard Worker #include "LogReaderList.h"
26*598139dcSAndroid Build Coastguard Worker #include "LogStatistics.h"
27*598139dcSAndroid Build Coastguard Worker #include "LogTags.h"
28*598139dcSAndroid Build Coastguard Worker #include "LogdLock.h"
29*598139dcSAndroid Build Coastguard Worker 
30*598139dcSAndroid Build Coastguard Worker class SimpleLogBuffer : public LogBuffer {
31*598139dcSAndroid Build Coastguard Worker   public:
32*598139dcSAndroid Build Coastguard Worker     SimpleLogBuffer(LogReaderList* reader_list, LogTags* tags, LogStatistics* stats);
33*598139dcSAndroid Build Coastguard Worker     ~SimpleLogBuffer();
34*598139dcSAndroid Build Coastguard Worker     void Init() override final;
35*598139dcSAndroid Build Coastguard Worker 
36*598139dcSAndroid Build Coastguard Worker     int Log(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid, pid_t tid, const char* msg,
37*598139dcSAndroid Build Coastguard Worker             uint16_t len) override;
38*598139dcSAndroid Build Coastguard Worker     std::unique_ptr<FlushToState> CreateFlushToState(uint64_t start, LogMask log_mask)
39*598139dcSAndroid Build Coastguard Worker             REQUIRES(logd_lock) override;
40*598139dcSAndroid Build Coastguard Worker     bool FlushTo(LogWriter* writer, FlushToState& state,
41*598139dcSAndroid Build Coastguard Worker                  const std::function<FilterResult(log_id_t log_id, pid_t pid, uint64_t sequence,
42*598139dcSAndroid Build Coastguard Worker                                                   log_time realtime)>& filter)
43*598139dcSAndroid Build Coastguard Worker             REQUIRES(logd_lock) override;
44*598139dcSAndroid Build Coastguard Worker 
45*598139dcSAndroid Build Coastguard Worker     bool Clear(log_id_t id, uid_t uid) override;
46*598139dcSAndroid Build Coastguard Worker     size_t GetSize(log_id_t id) override;
47*598139dcSAndroid Build Coastguard Worker     bool SetSize(log_id_t id, size_t size) override final;
48*598139dcSAndroid Build Coastguard Worker 
sequence()49*598139dcSAndroid Build Coastguard Worker     uint64_t sequence() const override { return sequence_.load(std::memory_order_relaxed); }
50*598139dcSAndroid Build Coastguard Worker 
51*598139dcSAndroid Build Coastguard Worker   protected:
52*598139dcSAndroid Build Coastguard Worker     virtual bool Prune(log_id_t id, unsigned long prune_rows, uid_t uid) REQUIRES(logd_lock);
53*598139dcSAndroid Build Coastguard Worker     virtual void LogInternal(LogBufferElement&& elem) REQUIRES(logd_lock);
54*598139dcSAndroid Build Coastguard Worker 
55*598139dcSAndroid Build Coastguard Worker     // Returns an iterator to the oldest element for a given log type, or logs_.end() if
56*598139dcSAndroid Build Coastguard Worker     // there are no logs for the given log type. Requires logs_logd_lock to be held.
57*598139dcSAndroid Build Coastguard Worker     std::list<LogBufferElement>::iterator GetOldest(log_id_t log_id) REQUIRES(logd_lock);
58*598139dcSAndroid Build Coastguard Worker     std::list<LogBufferElement>::iterator Erase(std::list<LogBufferElement>::iterator it)
59*598139dcSAndroid Build Coastguard Worker             REQUIRES(logd_lock);
60*598139dcSAndroid Build Coastguard Worker     void KickReader(LogReaderThread* reader, log_id_t id, unsigned long prune_rows)
61*598139dcSAndroid Build Coastguard Worker             REQUIRES(logd_lock);
62*598139dcSAndroid Build Coastguard Worker 
stats()63*598139dcSAndroid Build Coastguard Worker     LogStatistics* stats() { return stats_; }
reader_list()64*598139dcSAndroid Build Coastguard Worker     LogReaderList* reader_list() { return reader_list_; }
max_size(log_id_t id)65*598139dcSAndroid Build Coastguard Worker     size_t max_size(log_id_t id) REQUIRES_SHARED(logd_lock) { return max_size_[id]; }
66*598139dcSAndroid Build Coastguard Worker 
67*598139dcSAndroid Build Coastguard Worker   private:
68*598139dcSAndroid Build Coastguard Worker     bool ShouldLog(log_id_t log_id, const char* msg, uint16_t len);
69*598139dcSAndroid Build Coastguard Worker     void MaybePrune(log_id_t id) REQUIRES(logd_lock);
70*598139dcSAndroid Build Coastguard Worker 
71*598139dcSAndroid Build Coastguard Worker     LogReaderList* reader_list_;
72*598139dcSAndroid Build Coastguard Worker     LogTags* tags_;
73*598139dcSAndroid Build Coastguard Worker     LogStatistics* stats_;
74*598139dcSAndroid Build Coastguard Worker 
75*598139dcSAndroid Build Coastguard Worker     std::atomic<uint64_t> sequence_ = 1;
76*598139dcSAndroid Build Coastguard Worker 
77*598139dcSAndroid Build Coastguard Worker     size_t max_size_[LOG_ID_MAX] GUARDED_BY(logd_lock);
78*598139dcSAndroid Build Coastguard Worker     std::list<LogBufferElement> logs_ GUARDED_BY(logd_lock);
79*598139dcSAndroid Build Coastguard Worker     // Keeps track of the iterator to the oldest log message of a given log type, as an
80*598139dcSAndroid Build Coastguard Worker     // optimization when pruning logs.  Use GetOldest() to retrieve.
81*598139dcSAndroid Build Coastguard Worker     std::optional<std::list<LogBufferElement>::iterator> oldest_[LOG_ID_MAX] GUARDED_BY(logd_lock);
82*598139dcSAndroid Build Coastguard Worker };
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