gabime/spdlog

# spdlog [](https://github.com/gabime/spdlog/actions/workflows/linux.yml)  [](https://github.com/gabime/spdlog/actions/workflows/windows.yml)  [](https://github.com/gabime/spdlog/actions/workflows/macos.yml)  [](https://ci.appveyor.com/project/gabime/spdlog) [](https://github.com/gabime/spdlog/releases/latest) 快速的 C++ 日志库 ## 安装 #### 仅头文件版本 将 include [文件夹](include/spdlog) 复制到您的构建树中，并使用 C++11 编译器。 #### 编译版本（推荐 - 编译速度快得多） ``` $ git clone https://github.com/gabime/spdlog.git $ cd spdlog && mkdir build && cd build $ cmake .. && cmake --build . ``` 请参阅示例 [CMakeLists.txt](example/CMakeLists.txt) 了解如何使用。 ## 平台 * Linux, FreeBSD, OpenBSD, Solaris, AIX * Windows (msvc 2013+, cygwin) * macOS (clang 3.5+) * Android ## 包管理器： * Debian: `sudo apt install libspdlog-dev` * Homebrew: `brew install spdlog` * MacPorts: `sudo port install spdlog` * FreeBSD: `pkg install spdlog` * Fedora: `dnf install spdlog` * Gentoo: `emerge dev-libs/spdlog` * Arch Linux: `pacman -S spdlog` * openSUSE: `sudo zypper in spdlog-devel` * ALT Linux: `apt-get install libspdlog-devel` * vcpkg: `vcpkg install spdlog` * conan: `conan install --requires=spdlog/[*]` * conda: `conda install -c conda-forge spdlog` * build2: ```depends: spdlog ^1.8.2``` ## 特性 * 非常快（见下方的 [基准测试](#benchmarks)）。 * 仅头文件或编译模式 * 功能丰富的格式化，使用优秀的 [fmt](https://github.com/fmtlib/fmt) 库。 * 异步模式（可选） * [自定义](https://github.com/gabime/spdlog/wiki/Custom-formatting)格式化。 * 多/单线程日志记录器。 * 多种日志目标： * 滚动日志文件。 * 每日日志文件。 * 控制台日志（支持颜色）。 * syslog。 * Windows 事件日志。 * Windows 调试器（```OutputDebugString(..)```）。 * 记录到 Qt 控件（[示例](#log-to-qt-with-nice-colors)）。 * 易于通过自定义日志目标[扩展](https://github.com/gabime/spdlog/wiki/Sinks#implementing-your-own-sink)。 * 日志过滤 - 日志级别可以在运行时以及编译时修改。 * 支持从 argv 或环境变量加载日志级别。 * [Backtrace](#backtrace-support) 支持 - 将调试消息存储在环形缓冲区中，并在稍后按需显示。 ## 使用示例 #### 基本用法 ``` #include "spdlog/spdlog.h" int main() { spdlog::info("Welcome to spdlog!"); spdlog::error("Some error message with arg: {}", 1); spdlog::warn("Easy padding in numbers like {:08d}", 12); spdlog::critical("Support for int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b}", 42); spdlog::info("Support for floats {:03.2f}", 1.23456); spdlog::info("Positional args are {1} {0}..", "too", "supported"); spdlog::info("{:<30}", "left aligned"); spdlog::set_level(spdlog::level::debug); // Set *global* log level to debug spdlog::debug("This message should be displayed.."); // change log pattern spdlog::set_pattern("[%H:%M:%S %z] [%n] [%^---%L---%$] [thread %t] %v"); // Compile time log levels // Note that this does not change the current log level, it will only // remove (depending on SPDLOG_ACTIVE_LEVEL) the call on the release code. SPDLOG_TRACE("Some trace message with param {}", 42); SPDLOG_DEBUG("Some debug message"); } ``` #### 创建 stdout/stderr 日志记录器对象 ``` #include "spdlog/spdlog.h" #include "spdlog/sinks/stdout_color_sinks.h" void stdout_example() { // create a color multi-threaded logger auto console = spdlog::stdout_color_mt("console"); auto err_logger = spdlog::stderr_color_mt("stderr"); spdlog::get("console")->info("loggers can be retrieved from a global registry using the spdlog::get(logger_name)"); } ``` #### 基本文件日志记录器 ``` #include "spdlog/sinks/basic_file_sink.h" void basic_logfile_example() { try { auto logger = spdlog::basic_logger_mt("basic_logger", "logs/basic-log.txt"); } catch (const spdlog::spdlog_ex &ex) { std::cout << "Log init failed: " << ex.what() << std::endl; } } ``` #### 滚动文件 ``` #include "spdlog/sinks/rotating_file_sink.h" void rotating_example() { // Create a file rotating logger with 5 MB size max and 3 rotated files auto max_size = 1048576 * 5; auto max_files = 3; auto logger = spdlog::rotating_logger_mt("some_logger_name", "logs/rotating.txt", max_size, max_files); } ``` #### 每日文件 ``` #include "spdlog/sinks/daily_file_sink.h" void daily_example() { // Create a daily logger - a new file is created every day at 2:30 am auto logger = spdlog::daily_logger_mt("daily_logger", "logs/daily.txt", 2, 30); } ``` #### Backtrace 支持 ``` // Debug messages can be stored in a ring buffer instead of being logged immediately. // This is useful to display debug logs only when needed (e.g. when an error happens). // When needed, call dump_backtrace() to dump them to your log. spdlog::enable_backtrace(32); // Store the latest 32 messages in a buffer. // or my_logger->enable_backtrace(32).. for(int i = 0; i < 100; i++) { spdlog::debug("Backtrace message {}", i); // not logged yet.. } // e.g. if some error happened: spdlog::dump_backtrace(); // log them now! show the last 32 messages // or my_logger->dump_backtrace(32).. ``` #### 定期刷新 ``` // periodically flush all *registered* loggers every 3 seconds: // warning: only use if all your loggers are thread-safe ("_mt" loggers) spdlog::flush_every(std::chrono::seconds(3)); ``` #### 计时器 ``` // Stopwatch support for spdlog #include "spdlog/stopwatch.h" void stopwatch_example() { spdlog::stopwatch sw; spdlog::debug("Elapsed {}", sw); spdlog::debug("Elapsed {:.3}", sw); } ``` #### 以十六进制记录二进制数据 ``` // many types of std::container types can be used. // ranges are supported too. // format flags: // {:X} - print in uppercase. // {:s} - don't separate each byte with space. // {:p} - don't print the position on each line start. // {:n} - don't split the output into lines. // {:a} - show ASCII if :n is not set. #include "spdlog/fmt/bin_to_hex.h" void binary_example() { auto console = spdlog::get("console"); std::array buf; console->info("Binary example: {}", spdlog::to_hex(buf)); console->info("Another binary example:{:n}", spdlog::to_hex(std::begin(buf), std::begin(buf) + 10)); // more examples: // logger->info("uppercase: {:X}", spdlog::to_hex(buf)); // logger->info("uppercase, no delimiters: {:Xs}", spdlog::to_hex(buf)); // logger->info("uppercase, no delimiters, no position info: {:Xsp}", spdlog::to_hex(buf)); } ``` #### 具有多个 sink 的日志记录器 - 每个 sink 都有不同的格式和日志级别 ``` // create a logger with 2 targets, with different log levels and formats. // The console will show only warnings or errors, while the file will log all. void multi_sink_example() { auto console_sink = std::make_shared(); console_sink->set_level(spdlog::level::warn); console_sink->set_pattern("[multi_sink_example] [%^%l%$] %v"); auto file_sink = std::make_shared("logs/multisink.txt", true); file_sink->set_level(spdlog::level::trace); spdlog::logger logger("multi_sink", {console_sink, file_sink}); 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"); } ``` #### 注册多个日志记录器 - 更改全局级别 ``` // Creation of loggers. Set levels to all registered loggers. void set_level_example() { auto logger1 = spdlog::basic_logger_mt("logger1", "logs/logger1.txt"); auto logger2 = spdlog::basic_logger_mt("logger2", "logs/logger2.txt"); spdlog::set_default_logger(logger2); spdlog::default_logger()->set_level(spdlog::level::trace); // set level for the default logger (logger2) to trace spdlog::trace("trace message to the logger2 (specified as default)"); spdlog::set_level(spdlog::level::off) // (sic!) set level for *all* registered loggers to off (disable) logger1.warn("warn message will not appear because the level set to off"); logger2.warn("warn message will not appear because the level set to off"); spdlog::warn("warn message will not appear because the level set to off"); } ``` #### 关于日志事件的用户自定义回调 ``` // create a logger with a lambda function callback, the callback will be called // each time something is logged to the logger void callback_example() { auto callback_sink = std::make_shared([](const spdlog::details::log_msg &msg) { // for example you can be notified by sending an email to yourself }); callback_sink->set_level(spdlog::level::err); auto console_sink = std::make_shared(); spdlog::logger logger("custom_callback_logger", {console_sink, callback_sink}); logger.info("some info log"); logger.error("critical issue"); // will notify you } ``` #### 异步日志记录 ``` #include "spdlog/async.h" #include "spdlog/sinks/basic_file_sink.h" void async_example() { // default thread pool settings can be modified *before* creating the async logger: // spdlog::init_thread_pool(8192, 1); // queue with 8k items and 1 backing thread. auto async_file = spdlog::basic_logger_mt("async_file_logger", "logs/async_log.txt"); // alternatively: // auto async_file = spdlog::create_async("async_file_logger", "logs/async_log.txt"); } ``` #### 具有多个 sink 的异步日志记录器 ``` #include "spdlog/async.h" #include "spdlog/sinks/stdout_color_sinks.h" #include "spdlog/sinks/rotating_file_sink.h" void multi_sink_example2() { spdlog::init_thread_pool(8192, 1); auto stdout_sink = std::make_shared(); auto rotating_sink = std::make_shared("mylog.txt", 1024*1024*10, 3); std::vector sinks {stdout_sink, rotating_sink}; auto logger = std::make_shared("loggername", sinks.begin(), sinks.end(), spdlog::thread_pool(), spdlog::async_overflow_policy::block); spdlog::register_logger(logger); } ``` #### 用户自定义类型 ``` template<> struct fmt::formatter : fmt::formatter { auto format(my_type my, format_context &ctx) const -> decltype(ctx.out()) { return fmt::format_to(ctx.out(), "[my_type i={}]", my.i); } }; void user_defined_example() { spdlog::info("user defined type: {}", my_type(14)); } ``` #### 日志模式中的用户自定义标志 ``` // Log patterns can contain custom flags. // the following example will add new flag '%*' - which will be bound to a instance. #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 clone() const override { return spdlog::details::make_unique(); } }; void custom_flags_example() { auto formatter = std::make_unique(); formatter->add_flag('*').set_pattern("[%n] [%*] [%^%l%$] %v"); spdlog::set_formatter(std::move(formatter)); } ``` #### 自定义错误处理程序 ``` void err_handler_example() { // can be set globally or per logger(logger->set_error_handler(..)) spdlog::set_error_handler([](const std::string &msg) { spdlog::get("console")->error("*** LOGGER ERROR ***: {}", msg); }); spdlog::get("console")->info("some invalid message to trigger an error {}{}{}{}", 3); } ``` #### syslog ``` #include "spdlog/sinks/syslog_sink.h" void syslog_example() { std::string ident = "spdlog-example"; auto syslog_logger = spdlog::syslog_logger_mt("syslog", ident, LOG_PID); syslog_logger->warn("This is warning that will end up in syslog."); } ``` #### Android 示例 ``` #include "spdlog/sinks/android_sink.h" void android_example() { std::string tag = "spdlog-android"; auto android_logger = spdlog::android_logger_mt("android", tag); android_logger->critical("Use \"adb shell logcat\" to view this message."); } ``` #### 从环境变量或 argv 加载日志级别 ``` #include "spdlog/cfg/env.h" int main (int argc, char *argv[]) { spdlog::cfg::load_env_levels(); // or specify the env variable name: // MYAPP_LEVEL=info,mylogger=trace && ./example // spdlog::cfg::load_env_levels("MYAPP_LEVEL"); // or from the command line: // ./example SPDLOG_LEVEL=info,mylogger=trace // #include "spdlog/cfg/argv.h" // for loading levels from argv // spdlog::cfg::load_argv_levels(argc, argv); } ``` 然后您可以： ``` $ export SPDLOG_LEVEL=info,mylogger=trace $ ./example ``` #### 日志文件打开/关闭事件处理程序 ``` // You can get callbacks from spdlog before/after a log file has been opened or closed. // This is useful for cleanup procedures or for adding something to the start/end of the log file. void file_events_example() { // pass the spdlog::file_event_handlers to file sinks for open/close log file notifications spdlog::file_event_handlers handlers; handlers.before_open = [](spdlog::filename_t filename) { spdlog::info("Before opening {}", filename); }; handlers.after_open = [](spdlog::filename_t filename, std::FILE *fstream) { fputs("After opening\n", fstream); }; handlers.before_close = [](spdlog::filename_t filename, std::FILE *fstream) { fputs("Before closing\n", fstream); }; handlers.after_close = [](spdlog::filename_t filename) { spdlog::info("After closing {}", filename); }; auto my_logger = spdlog::basic_logger_st("some_logger", "logs/events-sample.txt", true, handlers); } ``` #### 替换默认日志记录器 ``` void replace_default_logger_example() { auto new_logger = spdlog::basic_logger_mt("new_default_logger", "logs/new-default-log.txt", true); spdlog::set_default_logger(new_logger); spdlog::info("new logger log message"); } ``` #### 使用漂亮的颜色记录到 Qt ``` #include "spdlog/spdlog.h" #include "spdlog/sinks/qt_sinks.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) { setMinimumSize(640, 480); auto log_widget = new QTextEdit(this); setCentralWidget(log_widget); int max_lines = 500; // keep the text widget to max 500 lines. remove old lines if needed. auto logger = spdlog::qt_color_logger_mt("qt_logger", log_widget, max_lines); logger->info("Some info message"); } ``` #### 映射诊断上下文 ``` // Mapped Diagnostic Context (MDC) is a map that stores key-value pairs (string values) in thread local storage. // Each thread maintains its own MDC, which loggers use to append diagnostic information to log outputs. // Note: it is not supported in asynchronous mode due to its reliance on thread-local storage. #include "spdlog/mdc.h" void mdc_example() { spdlog::mdc::put("key1", "value1"); spdlog::mdc::put("key2", "value2"); // if not using the default format, use the %& formatter to print mdc data // spdlog::set_pattern("[%H:%M:%S %z] [%^%L%$] [%&] %v"); } ``` ## 基准测试 以下是在 Ubuntu 64 位、Intel i7-4770 CPU @ 3.40GHz 上进行的一些[基准测试](bench/bench.cpp) #### 同步模式 ``` [info] ************************************************************** [info] Single thread, 1,000,000 iterations [info] ************************************************************** [info] basic_st Elapsed: 0.17 secs 5,777,626/sec [info] rotating_st Elapsed: 0.18 secs 5,475,894/sec [info] daily_st Elapsed: 0.20 secs 5,062,659/sec [info] empty_logger Elapsed: 0.07 secs 14,127,300/sec [info] ************************************************************** [info] C-string (400 bytes). Single thread, 1,000,000 iterations [info] ************************************************************** [info] basic_st Elapsed: 0.41 secs 2,412,483/sec [info] rotating_st Elapsed: 0.72 secs 1,389,196/sec [info] daily_st Elapsed: 0.42 secs 2,393,298/sec [info] null_st Elapsed: 0.04 secs 27,446,957/sec [info] ************************************************************** [info] 10 threads, competing over the same logger object, 1,000,000 iterations [info] ************************************************************** [info] basic_mt Elapsed: 0.60 secs 1,659,613/sec [info] rotating_mt Elapsed: 0.62 secs 1,612,493/sec [info] daily_mt Elapsed: 0.61 secs 1,638,305/sec [info] null_mt Elapsed: 0.16 secs 6,272,758/sec ``` #### 异步模式 ``` [info] ------------------------------------------------- [info] Messages : 1,000,000 [info] Threads : 10 [info] Queue : 8,192 slots [info] Queue memory : 8,192 x 272 = 2,176 KB [info] ------------------------------------------------- [info] [info] ********************************* [info] Queue Overflow Policy: block [info] ********************************* [info] Elapsed: 1.70784 secs 585,535/sec [info] Elapsed: 1.69805 secs 588,910/sec [info] Elapsed: 1.7026 secs 587,337/sec [info] [info] ********************************* [info] Queue Overflow Policy: overrun [info] ********************************* [info] Elapsed: 0.372816 secs 2,682,285/sec [info] Elapsed: 0.379758 secs 2,633,255/sec [info] Elapsed: 0.373532 secs 2,677,147/sec ``` ## 文档 文档可以在 [wiki](https://github.com/gabime/spdlog/wiki) 页面中找到。 ### 技术支持

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