后端【免费下载链接】spdlogFast C logging library.项目地址https://gitcode.com/GitHub_Trending/sp/spdlog点击查看免费下载本篇技术指南以 spdlog 仓库的 README.md 为主体系统讲解这款 C 日志库的完整使用方法从两种安装形态纯头文件版 / 编译版的选择、全局默认 Logger 的快速上手到文件轮转、每日日志、多 Sink、异步日志、Backtrace 与 MDC 等进阶特性并配合仓库源码佐证底层实现原理。读完本文你将能够独立完成 spdlog 的工程集成并针对自己的业务场景搭建一套高效、可裁剪的日志方案。spdlog 是一个快速的开源 C 日志库当前仓库版本为 1.17.0见 include/spdlog/version.h。它的核心设计可以概括为logger记录器持有多个 sink输出目标每个 sink 拥有独立的 formatter格式化器消息先按级别过滤再经格式化后写入对应目标这一模型在 include/spdlog/logger.h 中有明确注释说明。安装与工程集成spdlog 提供两种使用形态可根据编译耗时与分发方式取舍。纯头文件版Header-only把仓库的 include/spdlog 目录整体复制到你的构建树中然后使用 C11 编译器直接编译即可。此时所有实现都以inline形式内联进每个翻译单元无需链接额外库文件。对应机制见 include/spdlog/common.h 中SPDLOG_INLINE的宏定义头文件模式下定义为inline。编译版推荐编译更快$ git clone https://github.com/gabime/spdlog.git $ cd spdlog mkdir build cd build $ cmake .. cmake --build .编译版把实现集中到少量.cpp源文件中如 src/spdlog.cpp、src/file_sinks.cpp、src/async.cpp 等完整清单见 CMakeLists.txt只在编译库本身时承担模板展开成本下游工程编译速度明显更快。这是 README 推荐的方式。通过 CMake 集成作为独立项目构建后通过find_package(spdlog)引入链接目标为spdlog::spdlog静态库或spdlog::spdlog_header_only头文件接口库这两个 target 的别名定义在 CMakeLists.txt也可以把仓库作为子目录add_subdirectory(spdlog)直接加入你的工程仓库默认将构建类型设为 Release见 CMakeLists.txt并默认开启SPDLOG_INSTALL生成安装目标同时产出 CMake 配置包与 pkg-config 文件spdlog.pc、spdlog_header_only.pc模板见 cmake/spdlog.pc.in。包管理器安装平台 / 工具命令Debian / Ubuntusudo apt install libspdlog-devHomebrew (macOS)brew install spdlogMacPortssudo port install spdlogFreeBSDpkg install spdlogFedoradnf install spdlogGentooemerge dev-libs/spdlogArch Linuxpacman -S spdlogopenSUSEsudo zypper in spdlog-develALT Linuxapt-get install libspdlog-develvcpkgvcpkg install spdlogconanconan install --requiresspdlog/[*]condaconda install -c conda-forge spdlogbuild2depends: spdlog ^1.8.2支持的平台README 列出的平台覆盖Linux、FreeBSD、OpenBSD、Solaris、AIXWindowsMSVC 2013、CygwinmacOSclang 3.5AndroidCMake 构建时会自动链接log库见 CMakeLists.txt快速上手默认 Logger 与全局 API最简单的方式是直接使用全局默认 Loggerspdlog::info(...)等自由函数。默认 Logger 在注册表初始化时被自动创建在 Windows 上对应wincolor_stdout_sink_mt彩色控制台输出其他平台对应ansicolor_stdout_sink_mt见 include/spdlog/details/registry-inl.h。若要省去这极小的初始化开销可在 include/spdlog/tweakme.h 中定义SPDLOG_DISABLE_DEFAULT_LOGGER。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); }上述示例中消息格式化完全复用 fmt 库的语法{}占位、{:08d}数字补零、{0:x}位置参数与进制、浮点精度、对齐等spdlog::set_level是全局级别设置会作用于所有已注册 Logger实现见 include/spdlog/details/registry-inl.h 的registry::set_levelSPDLOG_TRACE/SPDLOG_DEBUG等宏受编译期级别SPDLOG_ACTIVE_LEVEL控制编译时级别不够时会被展开为(void)0即零运行时开销地移除调用宏定义见 include/spdlog/spdlog.h。日志级别体系级别枚举定义在 include/spdlog/common.h从低到高依次为枚举值数值说明trace0最细粒度调试信息debug1调试信息info2常规信息运行时默认级别对应SPDLOG_LEVEL_INFOwarn3警告err4错误critical5严重错误off6关闭日志每个 Logger 自带一个原子级别level_t即std::atomicint可通过SPDLOG_NO_ATOMIC_LEVELS关闭原子性以换取极端性能见 include/spdlog/common.h消息级别大于等于Logger 级别时才会被记录判断逻辑见 include/spdlog/logger.h 的should_log。创建与管理 Logger除了全局 APIspdlog 允许创建带名字的 Logger并通过全局注册表details::registry单例统一管理支持spdlog::get(name)按名字取回。stdout / stderr Logger#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)); }命名后缀约定_mt表示多线程安全内部加锁sink 使用互斥量_st表示单线程内部使用null_mutex无锁见 include/spdlog/details/null_mutex.h。基本文件 Logger#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; } }注意文件路径所在目录必须已存在spdlog 不会自动创建目录初始化失败如目录不存在、无写权限会抛出spdlog::spdlog_ex因此实际工程中通常要包在try/catch里。底层实现见 include/spdlog/sinks/basic_file_sink-inl.h每条消息先由 sink 私有的 formatter 格式化进memory_buf_t再写入文件flush_()才真正落盘。注册多个 Logger 并批量设置级别// 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); }set_default_logger会把新 Logger 同时写入注册表并替换默认 Logger见 include/spdlog/details/registry-inl.h。注意默认 APIspdlog::info()等为追求速度直接持有默认 Logger 的裸指针default_logger_raw()因此set_default_logger()不应与默认 API 并发调用见 include/spdlog/spdlog.h 的注释警告。其他常用注册表操作spdlog::register_logger(logger)重名会抛异常、spdlog::register_or_replace(logger)、spdlog::drop(name)/drop_all()、spdlog::shutdown()停止后台线程并清理见 include/spdlog/spdlog.h。文件日志轮转、每日与事件回调轮转文件Rotating#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); }当当前文件达到max_size字节时spdlog 会按序号滚动rotating.txt→rotating.1.txt→ …最多保留max_files个文件实现见 include/spdlog/sinks/rotating_file_sink.h。每日文件Daily#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); }传入的小时/分钟如2, 30表示每天在该时刻切换新文件。同类实现还有 include/spdlog/sinks/hourly_file_sink.h按小时切分。文件打开/关闭事件回调// 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); }file_event_handlers结构体包含before_open、after_open、before_close、after_close四个可空回调字段定义见 include/spdlog/common.h可用于在文件头尾追加内容或执行清理基础文件 sink 的构造函数会将其透传给内部的file_helper_见 include/spdlog/sinks/basic_file_sink-inl.h。多 Sink不同目标、不同级别、不同格式一个 Logger 可以同时挂载多个 Sink每个 Sink 拥有独立的级别与格式化器天然支持控制台只看告警、文件记录全部这类需求// 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_sharedspdlog::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_sharedspdlog::sinks::basic_file_sink_mt(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); }%^...%$是颜色标记中间内容按级别着色%l是完整级别名。实现上Sink 基类include/spdlog/sinks/sink.h为每个 Sink 保存一份独立的 formatter 拷贝便于缓存格式化数据如缓存的日期部分这正对应 include/spdlog/logger.h 开头注释所述的设计要点。异步日志异步模式下日志消息被推入线程池队列由后台线程消费调用线程不会被文件 I/O 阻塞。所有异步 Logger 共享同一个全局线程池。基本异步文件 Logger#include spdlog/async.h #include spdlog/sinks/basic_file_sink.h void async_example() { // default thread pool settings can be modified *before* creating the async logger: // spdlog::init_thread_pool(8192, 1); // queue with 8k items and 1 backing thread. auto async_file spdlog::basic_logger_mtspdlog::async_factory(async_file_logger, logs/async_log.txt); // alternatively: // auto async_file spdlog::create_asyncspdlog::sinks::basic_file_sink_mt(async_file_logger, logs/async_log.txt); }默认线程池队列容量为8192条消息、1个后台线程常量定义见 include/spdlog/async.h若全局线程池尚不存在会在首次创建异步 Logger 时按默认参数自动建立spdlog::init_thread_pool(q_size, thread_count)必须在创建任何异步 Logger 之前调用才生效async_factory使用async_overflow_policy::block队列满时阻塞调用线程另有async_factory_nonblockoverrun_oldest丢弃最旧消息、不阻塞以及对应的create_async_nb便捷函数见 include/spdlog/async.h。异步多 Sink Logger#include spdlog/async.h #include spdlog/sinks/stdout_color_sinks.h #include spdlog/sinks/rotating_file_sink.h void multi_sink_example2() { spdlog::init_thread_pool(8192, 1); auto stdout_sink std::make_sharedspdlog::sinks::stdout_color_sink_mt (); auto rotating_sink std::make_sharedspdlog::sinks::rotating_file_sink_mt(mylog.txt, 1024*1024*10, 3); std::vectorspdlog::sink_ptr sinks {stdout_sink, rotating_sink}; auto logger std::make_sharedspdlog::async_logger(loggername, sinks.begin(), sinks.end(), spdlog::thread_pool(), spdlog::async_overflow_policy::block); spdlog::register_logger(logger); }这里直接构造async_logger并显式指定溢出策略再用register_logger登记。队列中的每条消息都持有指向源 Logger 的shared_ptr因此即使 Logger 在队列还有未处理消息时被释放其析构也会被推迟到消息全部处理完毕机制说明见 include/spdlog/async.h 头部注释。格式化与模式Pattern自定义模式spdlog::set_pattern([%H:%M:%S %z] [%n] [%^---%L---%$] [thread %t] %v);常用模式符包括%H:%M:%S时间、%z时区偏移、%nLogger 名、%L级别、%t线程号、%v消息本体等。set_pattern的完整签名支持第二个参数指定本地时间或 UTC 时间pattern_time_type::local/utc见 include/spdlog/common.h。模式在pattern_formatter构造时被编译成一组flag_formatter对象编译逻辑见 include/spdlog/pattern_formatter-inl.h并支持%8X这类带宽度/对齐/截断的填充修饰padding_info定义见 include/spdlog/pattern_formatter.h。用户自定义类型只要为该类型特化fmt::formatter即可直接作为日志参数template struct fmt::formattermy_type : fmt::formatterstd::string { 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)); }自定义模式标记Custom Flag通过继承spdlog::custom_flag_formatter并实现format()与clone()可以为模式添加私有标记// Log patterns can contain custom flags. // the following example will add new flag %* - which will be bound to a my_formatter_flag 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_ptrcustom_flag_formatter clone() const override { return spdlog::details::make_uniquemy_formatter_flag(); } }; void custom_flags_example() { auto formatter std::make_uniquespdlog::pattern_formatter(); formatter-add_flagmy_formatter_flag(*).set_pattern([%n] [%*] [%^%l%$] %v); spdlog::set_formatter(std::move(formatter)); }add_flag的模板声明位于 include/spdlog/pattern_formatter.h。注意clone()必须返回新实例因为每个 Sink 都会持有 formatter 的独立拷贝。Backtrace 回溯支持调试信息可以先暂存到环形缓冲区等到真正需要时例如出错后再统一输出避免大量 debug 日志持续刷屏// 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)..enable_backtrace(n)会在 Logger 内激活一个容量为n的details::backtracer环形队列实现见 include/spdlog/details/backtracer.h 与 include/spdlog/details/circular_q.h此后即使消息级别低于当前日志级别也会被写入环形缓冲dump_backtrace()一次性把这些消息按正常流程输出。全局版spdlog::enable_backtrace(n)会作用于注册表内所有 Logger见 include/spdlog/details/registry-inl.h。对应测试见 tests/test_backtrace.cpp。定期刷新Periodic Flush与 Stopwatch// 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));flush_every通过注册表启动一个周期任务线程periodic_worker见 include/spdlog/details/periodic_worker.h每 3 秒对所有已注册 Logger 执行flush()。README 特别警告仅当所有 Logger 均为线程安全_mt时使用因为该线程会并发调用各 Logger 的 flush。此外还有按级别刷新的spdlog::flush_on(level::level_enum)与手动spdlog::flush_all()。Stopwatch 用于测量耗时并直接嵌入日志// Stopwatch support for spdlog #include spdlog/stopwatch.h void stopwatch_example() { spdlog::stopwatch sw; spdlog::debug(Elapsed {}, sw); spdlog::debug(Elapsed {:.3}, sw); }二进制数据 Hex 输出// many types of std::containerchar types can be used. // ranges are supported too. // format flags: // {:X} - print in uppercase. // {:s} - dont separate each byte with space. // {:p} - dont print the position on each line start. // {:n} - dont 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::arraychar, 80 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)); }spdlog::to_hex接受容器或迭代器区间配合:X大写、:s去分隔符、:p去行首位置、:n不换行、:aASCII 对照等格式标记输出。实现与测试见 include/spdlog/fmt/bin_to_hex.h 与 tests/test_bin_to_hex.cpp。回调 Sink 与自定义错误处理日志事件回调// 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_sharedspdlog::sinks::callback_sink_mt([](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_sharedspdlog::sinks::stdout_color_sink_mt(); spdlog::logger logger(custom_callback_logger, {console_sink, callback_sink}); logger.info(some info log); logger.error(critical issue); // will notify you }回调 sink 的实现见 include/spdlog/sinks/callback_sink.h可在每次日志写入时获得log_msg引用适合做告警通知、指标采集等旁路处理。自定义错误处理器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); }格式化失败等异常会被捕获并转交给错误处理器默认处理器以每秒最多 1 条的速率向 stderr 打印见 include/spdlog/logger.h 注释。set_error_handler可全局或按 Logger 设置。系统级输出syslog、Android、Qtsyslog#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#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.); }Qt 控件带彩色输出#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); }sink 实现见 include/spdlog/sinks/qt_sinks.h。此外仓库还提供 Windows 事件日志include/spdlog/sinks/win_eventlog_sink.h、MSVC 调试输出include/spdlog/sinks/msvc_sink.h、UDP/TCPinclude/spdlog/sinks/udp_sink.h、include/spdlog/sinks/tcp_sink.h、Kafkainclude/spdlog/sinks/kafka_sink.h、Loki、MongoDB 等丰富目标且 sink 基类include/spdlog/sinks/base_sink.h易于继承扩展自定义目标。从环境变量或命令行加载日志级别无需改代码即可在部署时控制日志级别还支持按 Logger 名单独设置#include spdlog/cfg/env.h int main (int argc, char *argv[]) { spdlog::cfg::load_env_levels(); // or specify the env variable name: // MYAPP_LEVELinfo,myloggertrace ./example // spdlog::cfg::load_env_levels(MYAPP_LEVEL); // or from the command line: // ./example SPDLOG_LEVELinfo,myloggertrace // #include spdlog/cfg/argv.h // for loading levels from argv // spdlog::cfg::load_argv_levels(argc, argv); }然后通过环境变量控制$ export SPDLOG_LEVELinfo,myloggertrace $ ./example语法为全局级别或级别,logger名级别,...可组合多个 Logger例如off,logger1debug,logger2info表示全局关闭、仅放开两个指定 Logger。实现见 include/spdlog/cfg/env.h读取环境变量后交给 include/spdlog/cfg/helpers.h 解析再经注册表的set_levels应用到各 Logger见 include/spdlog/details/registry-inl.h命令行版本位于 include/spdlog/cfg/argv.h。Mapped Diagnostic ContextMDCMDC 是一个存储于线程本地存储的键值映射让每条日志自动附带当前线程的诊断上下文如请求 ID、用户 ID// 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); }使用%模式标记即可把 MDC 内容拼入输出由于依赖线程局部存储异步模式不支持 MDCREADME 已明确标注。实现见 include/spdlog/mdc.h。基准测试参考README 给出的基准来自 bench/bench.cpp测试环境为 Ubuntu 64 位、Intel i7-4770 CPU 3.40GHz仅供同硬件条件下参考。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对比可见队列溢出策略为overrun丢弃最旧消息时吞吐显著高于block阻塞调用线程实际选型需在消息完整性与最低延迟之间权衡。基准源码位于 bench/bench.cpp另有 bench/async_bench.cpp、bench/latency.cpp 可自行复测。编译期裁剪tweakme 与 CMake 选项若要进一步压榨性能或裁剪特性可编辑 include/spdlog/tweakme.h 或在 CMake 中开启对应选项CMakeLists.txt 中均有同名option宏 / CMake 选项作用SPDLOG_CLOCK_COARSELinux 下改用CLOCK_REALTIME_COARSE粗时钟更快但精度差可能偏差数十毫秒SPDLOG_NO_SOURCE_LOC关闭__FILE__/__LINE__源码位置记录SPDLOG_NO_THREAD_ID关闭线程号查询模式中含%t时会输出 0SPDLOG_NO_TLS禁用线程本地存储程序 fork 后建议开启避免子进程线程号未定义SPDLOG_NO_ATOMIC_LEVELS级别改为非原子仅当不并发修改级别时使用SPDLOG_ACTIVE_LEVEL编译期日志级别默认SPDLOG_LEVEL_INFO宏调用按此裁剪为零开销SPDLOG_FMT_EXTERNAL使用外部 fmt 库替代内置副本SPDLOG_USE_STD_FORMAT改用 C20std::format需 C20 编译标准见 CMakeLists.txtSPDLOG_NO_EXCEPTIONS配合-fno-exceptions编译异常直接 abortSPDLOG_LEVEL_NAMES/SPDLOG_SHORT_LEVEL_NAMES自定义级别名称总结围绕 README.md 给出的完整示例与仓库源码可以确认spdlog 的价值在于极低的运行时开销 按需扩展的 sink 体系 编译期可裁剪三者结合。实践中的推荐路线是先用全局 API 快速验证再按模块创建具名 Logger 并通过SPDLOG_LEVEL环境变量做部署期调控高吞吐场景启用异步 Logger 并明确溢出策略需要排障上下文时组合 Backtrace 与 MDC。仓库的 tests 目录覆盖了上述绝大多数特性的行为验证如 tests/test_async.cpp、tests/test_file_logging.cpp、tests/test_pattern_formatter.cpp可作为深入学习与回归参考。赞分享后端【免费下载链接】spdlogFast C logging library.项目地址https://gitcode.com/GitHub_Trending/sp/spdlog点击查看免费下载相关推荐10个spdlog实战示例C高性能日志库完全指南10个spdlog实战示例C高性能日志库完全指南 spdlog是一个专为C设计的高性能日志库提供快速、灵活的日志记录解决方案。本文通过10个实用示例后端Glog日志库深度解析打造高性能C日志系统的实战手册Glog日志库深度解析打造高性能C日志系统的实战手册 在当今复杂的软件系统中日志记录是保障系统可观测性的基石。Google开发的glog日志库凭借其卓越后端革命性C日志库spdlog高性能异步日志记录新标杆革命性C日志库spdlog高性能异步日志记录新标杆 还在为C项目中的日志性能瓶颈而烦恼吗传统日志库在高并发场景下往往成为系统性能的拖累而spdlo后端上一篇告别繁琐登录tymon/jwt-auth让前后端认证像呼吸一样自然下一篇Android单元测试终极指南从隔离到集成测试的完整实践创作声明：本文部分内容由AI辅助生成（AIGC），仅供参考