aosp12/system/logging/logd/SimpleLogBuffer.h

84 lines
3.3 KiB
C++

/*
* Copyright (C) 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <atomic>
#include <list>
#include <mutex>
#include "LogBuffer.h"
#include "LogBufferElement.h"
#include "LogReaderList.h"
#include "LogStatistics.h"
#include "LogTags.h"
#include "LogdLock.h"
class SimpleLogBuffer : public LogBuffer {
public:
SimpleLogBuffer(LogReaderList* reader_list, LogTags* tags, LogStatistics* stats);
~SimpleLogBuffer();
void Init() override final;
int Log(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid, pid_t tid, const char* msg,
uint16_t len) override;
std::unique_ptr<FlushToState> CreateFlushToState(uint64_t start, LogMask log_mask)
REQUIRES(logd_lock) override;
bool FlushTo(LogWriter* writer, FlushToState& state,
const std::function<FilterResult(log_id_t log_id, pid_t pid, uint64_t sequence,
log_time realtime)>& filter)
REQUIRES(logd_lock) override;
bool Clear(log_id_t id, uid_t uid) override;
size_t GetSize(log_id_t id) override;
bool SetSize(log_id_t id, size_t size) override final;
uint64_t sequence() const override { return sequence_.load(std::memory_order_relaxed); }
protected:
virtual bool Prune(log_id_t id, unsigned long prune_rows, uid_t uid) REQUIRES(logd_lock);
virtual void LogInternal(LogBufferElement&& elem) REQUIRES(logd_lock);
// Returns an iterator to the oldest element for a given log type, or logs_.end() if
// there are no logs for the given log type. Requires logs_logd_lock to be held.
std::list<LogBufferElement>::iterator GetOldest(log_id_t log_id) REQUIRES(logd_lock);
std::list<LogBufferElement>::iterator Erase(std::list<LogBufferElement>::iterator it)
REQUIRES(logd_lock);
void KickReader(LogReaderThread* reader, log_id_t id, unsigned long prune_rows)
REQUIRES(logd_lock);
LogStatistics* stats() { return stats_; }
LogReaderList* reader_list() { return reader_list_; }
size_t max_size(log_id_t id) REQUIRES_SHARED(logd_lock) { return max_size_[id]; }
std::list<LogBufferElement>& logs() { return logs_; }
private:
bool ShouldLog(log_id_t log_id, const char* msg, uint16_t len);
void MaybePrune(log_id_t id) REQUIRES(logd_lock);
LogReaderList* reader_list_;
LogTags* tags_;
LogStatistics* stats_;
std::atomic<uint64_t> sequence_ = 1;
size_t max_size_[LOG_ID_MAX] GUARDED_BY(logd_lock);
std::list<LogBufferElement> logs_ GUARDED_BY(logd_lock);
// Keeps track of the iterator to the oldest log message of a given log type, as an
// optimization when pruning logs. Use GetOldest() to retrieve.
std::optional<std::list<LogBufferElement>::iterator> oldest_[LOG_ID_MAX] GUARDED_BY(logd_lock);
};