inc/spdlog/async_logger.h

/*************************************************************************/
/* spdlog - an extremely fast and easy to use c++11 logging library.     */
/* Copyright (c) 2014 Gabi Melman.                                       */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
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#pragma once

// Very fast asynchronous logger (millions of logs per second on an average desktop)
// Uses pre allocated lockfree queue for maximum throughput even under large number of threads.
// Creates a single back thread to pop messages from the queue and log them.
//
// Upon each log write the logger:
//    1. Checks if its log level is enough to log the message
//    2. Push a new copy of the message to a queue (or block the caller until space is available in the queue)
//    3. will throw spdlog_ex upon log exceptions
// Upong destruction, logs all remaining messages in the queue before destructing..

#include <chrono>
#include <functional>
#include "common.h"
#include "logger.h"
#include "spdlog.h"


namespace spdlog
{

namespace details
{
class async_log_helper;
}

class async_logger :public logger
{
public:
    template<class It>
    async_logger(const std::string& name,
                 const It& begin,
                 const It& end,
                 size_t queue_size,
                 const async_overflow_policy overflow_policy =  async_overflow_policy::block_retry,
                 const std::function<void()>& worker_warmup_cb = nullptr,
                 const std::chrono::milliseconds& flush_interval_ms = std::chrono::milliseconds::zero());

    async_logger(const std::string& logger_name,
                 sinks_init_list sinks,
                 size_t queue_size,
                 const async_overflow_policy overflow_policy = async_overflow_policy::block_retry,
                 const std::function<void()>& worker_warmup_cb = nullptr,
                 const std::chrono::milliseconds& flush_interval_ms = std::chrono::milliseconds::zero());

    async_logger(const std::string& logger_name,
                 sink_ptr single_sink,
                 size_t queue_size,
                 const async_overflow_policy overflow_policy =  async_overflow_policy::block_retry,
                 const std::function<void()>& worker_warmup_cb = nullptr,
                 const std::chrono::milliseconds& flush_interval_ms = std::chrono::milliseconds::zero());


protected:
    void _log_msg(details::log_msg& msg) override;
    void _set_formatter(spdlog::formatter_ptr msg_formatter) override;
    void _set_pattern(const std::string& pattern) override;

private:
    std::unique_ptr<details::async_log_helper> _async_log_helper;
};
}


#include "./details/async_logger_impl.h"