{

public:

AsyncLogging(const std::string& basename,

off_t rollsize, //long int,文件缓冲区中需要刷新时的字节数

size_t flushInterval = 3);

void start()

{

std::future<void> p = latch_.get_future();

running_ = true;

thread_.start();

p.get();

}

void stop()

{

running_ = false;

cond_.notify_one();

thread_.join();

}

void append(const char *logline, int len);

~AsyncLogging()

{

if(running_) {stop();}

}

private:

void threadFunc();

typedef eff::detail::FixedBuffer<eff::detail::kLargeBuffer> Buffer;

typedef std::vector<std::unique_ptr<Buffer>> BufferVector;

typedef BufferVector::value_type BufferPtr;

const int flushInterval_;

std::atomic<bool> running_;

const string basename;

const off_t rollSize;

Thread thread_;

std::promise<void> latch_;

std::mutex mutex_;

std::condition_variable cond_;

BufferPtr currentBuffer_; //GUARDED_BY(mutex_);

BufferPtr nextBuffer_ ;//GUARDED_BY(mutex_);

BufferVector buffers_ ;//GUARDED_BY(mutex_);