Spdlog记述：一-Aet

Bingliaolong 2023-07-07 16:40 Aet | 隐藏边栏 | 抢沙发 | 11 0

文章评分 4 次，平均分 5.0 ：

使用介绍

默认的

#include "spdlog/spdlog.h"

int main()

{

//Use the default logger (stdout, multi-threaded, colored)

spdlog::info("Hello, {}!", "World");

}

创建一个多线程日志记录器
1. 创建的日志记录器是多线程的，这意味着它可以被多个线程同时使用，而不会发生竞争条件或数据损坏
2. 用于创建多线程的循环日志记录器
循环日志记录器是指在达到指定大小后，会自动循环覆盖旧的日志文件并创建新的日志文件来存储日志消息
1. 循环日志记录器还可以设置要保留的旧日志文件的最大数量。
2. 当达到最大数量时，最旧的日志文件将被删除，以保持指定数量的日志文件

#include <iostream>

#include "spdlog/spdlog.h"

#include "spdlog/sinks/basic_file_sink.h" // support for basic file logging

#include "spdlog/sinks/rotating_file_sink.h" // support for rotating file logging

int main(int, char* [])

{

try

{

// 1

// Create basic file logger (not rotated)

auto my_logger = spdlog::basic_logger_mt("basic_logger", "logs/basic.txt");

// 2

// create a file rotating logger with 5mb size max and 3 rotated files

auto file_logger = spdlog::rotating_logger_mt("file_logger", "myfilename", 1024 * 1024 * 5, 3);

}

catch (const spdlog::spdlog_ex& ex)

{

std::cout << "Log initialization failed: " << ex.what() << std::endl;

}

工厂方法创建异步记录器
1. 使用异步日志记录器，日志消息将被异步地写入日志文件，而不会阻塞主线程的执行

#include <iostream>

#include "spdlog/spdlog.h"

#include "spdlog/async.h" //support for async logging.

#include "spdlog/sinks/basic_file_sink.h"

int main(int, char* [])

{

try

{

auto async_file = spdlog::basic_logger_mt<spdlog::async_factory>("async_file_logger", "logs/async_log.txt");

for (int i = 1; i < 101; ++i)

{

async_file->info("Async message #{}", i);

}

// Under VisualStudio, this must be called before main finishes to workaround a known VS issue

spdlog::drop_all();

}

catch (const spdlog::spdlog_ex& ex)

{

std::cout << "Log initialization failed: " << ex.what() << std::endl;

}

异步记录器，更改线程池

#include "spdlog/async.h" //support for async logging

#include "spdlog/sinks/daily_file_sink.h"

int main(int, char* [])

{

try

{

auto daily_sink = std::make_shared<spdlog::sinks::daily_file_sink_mt>("logfile", 23, 59);

// default thread pool settings can be modified *before* creating the async logger:

spdlog::init_thread_pool(10000, 1); // queue with 10K items and 1 backing thread.

auto async_file = spdlog::basic_logger_mt<spdlog::async_factory>("async_file_logger", "logs/async_log.txt");

spdlog::drop_all();

}

catch (const spdlog::spdlog_ex& ex)

{

std::cout << "Log initialization failed: " << ex.what() << std::endl;

}

创建共享同个接收器的多个记录器

#include <iostream>

#include "spdlog/spdlog.h"

#include "spdlog/sinks/daily_file_sink.h"

int main(int, char* [])

{

try

{

auto daily_sink = std::make_shared<spdlog::sinks::daily_file_sink_mt>("logfile", 23, 59);

// create synchronous loggers

auto net_logger = std::make_shared<spdlog::logger>("net", daily_sink);

auto hw_logger = std::make_shared<spdlog::logger>("hw", daily_sink);

auto db_logger = std::make_shared<spdlog::logger>("db", daily_sink);

net_logger->set_level(spdlog::level::critical); // independent levels

hw_logger->set_level(spdlog::level::debug);

// globally register the loggers so they can be accessed using spdlog::get(logger_name)

spdlog::register_logger(net_logger);

}

catch (const spdlog::spdlog_ex& ex)

{

std::cout << "Log initialization failed: " << ex.what() << std::endl;

}

创建具有多个接收器的记录器，每个接收器都有自己的格式和级别

// Logger with console and file output.

// the console will show only warnings or worse, while the file will log all messages.

#include <iostream>

#include "spdlog/spdlog.h"

#include "spdlog/sinks/stdout_color_sinks.h" // or "../stdout_sinks.h" if no colors needed

#include "spdlog/sinks/basic_file_sink.h"

int main(int, char* [])

{

try

{

auto console_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();

console_sink->set_level(spdlog::level::warn);

console_sink->set_pattern("[multi_sink_example] [%^%l%$] %v");

auto file_sink = std::make_shared<spdlog::sinks::basic_file_sink_mt>("logs/multisink.txt", true);

file_sink->set_level(spdlog::level::trace);

spdlog::sinks_init_list sink_list = { file_sink, console_sink };

spdlog::logger logger("multi_sink", sink_list.begin(), sink_list.end());

logger.set_level(spdlog::level::debug);

logger.warn("this should appear in both console and file");

logger.info("this message should not appear in the console, only in the file");

// or you can even set multi_sink logger as default logger

spdlog::set_default_logger(std::make_shared<spdlog::logger>("multi_sink", spdlog::sinks_init_list({console_sink, file_sink})));

}

catch (const spdlog::spdlog_ex& ex)

{

std::cout << "Log initialization failed: " << ex.what() << std::endl;

}

打印类

#include "spdlog/spdlog.h"

#include "spdlog/fmt/ostr.h" // must be included

#include "spdlog/sinks/stdout_sinks.h"

class some_class {};

std::ostream& operator<<(std::ostream& os, const some_class& c)

{

return os << "some_class";

}

void custom_class_example()

{

some_class c;

auto console = spdlog::stdout_logger_mt("console");

console->info("custom class with operator<<: {}..", c);

}

fmt格式化

#include <iterator>

#include "spdlog/spdlog.h"

#include "spdlog/fmt/ostr.h" // must be included

#include "spdlog/sinks/stdout_sinks.h"

class some_class {

int code;

};

template<typename OStream>

friend OStream &operator<<(OStream &os, const some_class& to_log)

{

fmt::format_to(std::ostream_iterator<char>(os), "{:04X}", to_log.code);

return os;

}

void custom_class_example()

{

some_class c; c.code = 17;

auto console = spdlog::stdout_logger_mt("console");

console->info("custom class with operator<< using fmt: {}..", c);

}

线程安全

非线程安全函数

set_error_handler(log_err_handler);

//- returns a reference to a non thread safe vector, so don't modify it concurrently

// (e.g. logger->sinks().push_back(new_sink);)

logger::sinks()

线程安全记录器

要创建线程安全记录器，请使用 _mt 工厂函数

1	auto logger = spdlog::basic_logger_mt(...);

单线程记录器

1	auto logger = spdlog::basic_logger_st(...);

线程安全接收器

以_mt（例如daily_file_sink_mt）结尾的接收器

非线程安全接收器

以_st（例如daily_file_sink_st）结尾的接收器

记录器

工程方法函数创建

//Create and return a shared_ptr to a multithreaded console logger.

#include "spdlog/sinks/stdout_color_sinks.h"

auto console = spdlog::stdout_color_mt("some_unique_name");

访问记录器

在任何地方可以使用线程安全的get获得操作记录器的共享指针
由于可能导致代码变慢，所以一个好的方法是在恰当的地方持有这个共享指针，不用总是去获取（获取意味着要操作锁）

1	spdlog::get("logger_name")

手动创建记录器

手动创建（通过构造）的记录器不会自动注册，所以调用get是获取不到的
所以手动创建的记录器需要注册一下

auto sink = std::make_shared<spdlog::sinks::stdout_sink_mt>();

auto my_logger = std::make_shared<spdlog::logger>("mylogger", sink);

// Optionally register the logger. This is only needed if you want to access it with spdlog::get("mylogger")

spdlog::register_logger(my_logger);

...

auto the_same_logger = spdlog::get("mylogger");

关于异步记录器

对于异步日志记录，spdlog 使用带有专用消息队列的共享全局线程池
它在消息队列中创建固定数量的预分配槽（64 位中每个槽约 256 字节）,可以用下面方式修改

1	spdlog::init_thread_pool(queue_size, backing_threads_count)

自定义格式

应用于所有注册的记录器

1	spdlog::set_pattern("* [%H:%M:%S %z] [thread %t] %v *");

特定的记录器

1	some_logger->set_pattern(">>>>>>>>> %H:%M:%S %z %v <<<<<<<<<");

特定接收器对象

1 2	some_logger->sinks()[0]->set_pattern(">>>>>>>>> %H:%M:%S %z %v <<<<<<<<<"); some_logger->sinks()[1]->set_pattern("..");

flag

flag meaning example

%v The actual text to log "some user text"

%t Thread id "1232"

%P Process id "3456"

%n Logger's name "some logger name"

%l The log level of the message "debug", "info", etc

%L Short log level of the message "D", "I", etc

%a Abbreviated weekday name "Thu"

%A Full weekday name "Thursday"

%b Abbreviated month name "Aug"

%B Full month name "August"

%c Date and time representation "Thu Aug 23 15:35:46 2014"

%C Year in 2 digits "14"

%Y Year in 4 digits "2014"

%D or %x Short MM/DD/YY date "08/23/14"

%m Month 01-12 "11"

%d Day of month 01-31 "29"

%H Hours in 24 format 00-23 "23"

%I Hours in 12 format 01-12 "11"

%M Minutes 00-59 "59"

%S Seconds 00-59 "58"

%e Millisecond part of the current second 000-999 "678"

%f Microsecond part of the current second 000000-999999 "056789"

%F Nanosecond part of the current second 000000000-999999999 "256789123"

%p AM/PM "AM"

%r 12 hour clock "02:55:02 PM"

%R 24-hour HH:MM time, equivalent to %H:%M "23:55"

%T or %X ISO 8601 time format (HH:MM:SS), equivalent to %H:%M:%S "23:55:59"

%z ISO 8601 offset from UTC in timezone ([+/-]HH:MM) "+02:00"

%E Seconds since the epoch "1528834770"

%% The % sign "%"

%+ spdlog's default format "[2014-10-31 23:46:59.678] [mylogger] [info] Some message"

%^ start color range (can be used only once) "[mylogger] [info(green)] Some message"

%$ end color range (for example %^[+++]%$ %v) (can be used only once) [+++] Some message

%@ Source file and line (use SPDLOG_TRACE(..), SPDLOG_INFO(...) etc. instead of spdlog::trace(...)) Same as %g:%# /some/dir/my_file.cpp:123

%s Basename of the source file (use SPDLOG_TRACE(..), SPDLOG_INFO(...) etc.) my_file.cpp

%g Full or relative path of the source file as appears in the __FILE__ macro (use SPDLOG_TRACE(..), SPDLOG_INFO(...) etc.) /some/dir/my_file.cpp

%# Source line (use SPDLOG_TRACE(..), SPDLOG_INFO(...) etc.) 123

%! Source function (use SPDLOG_TRACE(..), SPDLOG_INFO(...) etc. see tweakme for pretty-print) my_func

%o Elapsed time in milliseconds since previous message 456

%i Elapsed time in microseconds since previous message 456

%u Elapsed time in nanoseconds since previous message 11456

%O Elapsed time in seconds since previous message 4

对齐

align meaning example result

%<width><flag> Right align %8l " info"

%-<width><flag> Left align %-8l "info "

%=<width><flag> Center align %=8l " info "

自定义flag

#include "spdlog/pattern_formatter.h"

class my_formatter_flag : public spdlog::custom_flag_formatter

{

public:

void format(const spdlog::details::log_msg &, const std::tm &, spdlog::memory_buf_t &dest) override

{

std::string some_txt = "custom-flag";

dest.append(some_txt.data(), some_txt.data() + some_txt.size());

}

std::unique_ptr<custom_flag_formatter> clone() const override

{

return spdlog::details::make_unique<my_formatter_flag>();

}

};

void custom_flags_example()

{

auto formatter = std::make_unique<spdlog::pattern_formatter>();

formatter->add_flag<my_formatter_flag>('*').set_pattern("[%n] [%*] [%^%l%$] %v");

spdlog::set_formatter(std::move(formatter));

}

全局级别

1	#define SPDLOG_ACTIVE_LEVEL SPDLOG_LEVEL_TRACE

SPDLOG_LOGGER_TRACE(some_logger, "trace message");

SPDLOG_LOGGER_DEBUG(some_logger, "debug message");

SPDLOG_LOGGER_INFO(some_logger, "info message");

SPDLOG_LOGGER_WARN(some_logger, "warn message");

SPDLOG_LOGGER_ERROR(some_logger, "error message");

SPDLOG_LOGGER_CRITICAL(some_logger, "critical message");

使用介绍
线程安全
非线程安全函数
线程安全记录器
线程安全接收器
非线程安全接收器
记录器
工程方法函数创建
访问记录器
手动创建记录器
关于异步记录器
自定义格式
应用于所有注册的记录器
特定的记录器
特定接收器对象
flag
对齐
自定义flag
全局级别

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Bingliaolong 关注：0 粉丝：0 最后编辑于：2023-07-08

Everything will be better.

使用介绍

线程安全

非线程安全函数

线程安全记录器

线程安全接收器

非线程安全接收器

记录器

工程方法函数创建

访问记录器

手动创建记录器

关于异步记录器

自定义格式

应用于所有注册的记录器

特定的记录器

特定接收器对象

flag

对齐

自定义flag

全局级别

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