blob: 9a2d01ab5ef56de97309a20c3d6db4ee29378215 [file] [log] [blame]
/*
* 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 "rwlock.h"
class SimpleLogBuffer : public LogBuffer {
public:
SimpleLogBuffer(LogReaderList* reader_list, LogTags* tags, LogStatistics* stats);
~SimpleLogBuffer();
void Init() override;
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;
uint64_t FlushTo(
LogWriter* writer, uint64_t start, pid_t* lastTid,
const std::function<FlushToResult(const LogBufferElement* element)>& filter) override;
bool Clear(log_id_t id, uid_t uid) override;
unsigned long GetSize(log_id_t id) override;
int SetSize(log_id_t id, unsigned long size) override;
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(lock_);
virtual void LogInternal(LogBufferElement&& elem) REQUIRES(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_lock_ to be held.
std::list<LogBufferElement>::iterator GetOldest(log_id_t log_id) REQUIRES(lock_);
std::list<LogBufferElement>::iterator Erase(std::list<LogBufferElement>::iterator it)
REQUIRES(lock_);
void KickReader(LogReaderThread* reader, log_id_t id, unsigned long prune_rows)
REQUIRES_SHARED(lock_);
LogStatistics* stats() { return stats_; }
LogReaderList* reader_list() { return reader_list_; }
unsigned long max_size(log_id_t id) REQUIRES_SHARED(lock_) { return max_size_[id]; }
std::list<LogBufferElement>& logs() { return logs_; }
RwLock lock_;
private:
bool ShouldLog(log_id_t log_id, const char* msg, uint16_t len);
void MaybePrune(log_id_t id) REQUIRES(lock_);
LogReaderList* reader_list_;
LogTags* tags_;
LogStatistics* stats_;
std::atomic<uint64_t> sequence_ = 1;
unsigned long max_size_[LOG_ID_MAX] GUARDED_BY(lock_);
std::list<LogBufferElement> logs_ GUARDED_BY(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(lock_);
};