From c98d0c4c87235fdcf3ebe43c06536ffd45fc8156 Mon Sep 17 00:00:00 2001 From: William Wallace Date: Sat, 8 Mar 2025 16:01:37 -0800 Subject: [PATCH] Add Swift Package Manager support --- Package.swift | 44 +++ README.md | 1056 ++++++++++++++++++++++++------------------------- 2 files changed, 572 insertions(+), 528 deletions(-) create mode 100644 Package.swift diff --git a/Package.swift b/Package.swift new file mode 100644 index 00000000..8a168c60 --- /dev/null +++ b/Package.swift @@ -0,0 +1,44 @@ +// swift-tools-version: 5.8 + +import PackageDescription + +let package = Package( + name: "spdlog", + platforms: [ + .iOS(.v12), + .macOS(.v10_14), + ], + products: [ + .library( + name: "spdlog", + targets: ["spdlog"]), + ], + dependencies: [ + ], + targets: [ + .target( + name: "spdlog", + dependencies: [], + path: ".", + exclude: [ + "bench", + "cmake", + "example", + "logos", + "tests", + "scripts", + ], + sources: [ + "src", + "include", + ], + publicHeadersPath: "include", + cxxSettings: [ + .headerSearchPath("spdlog"), + .define("SPDLOG_COMPILED_LIB"), + ], + linkerSettings: [] + ), + ], + cxxLanguageStandard: .cxx11 +) diff --git a/README.md b/README.md index b4fb2073..b7082c90 100644 --- a/README.md +++ b/README.md @@ -1,528 +1,528 @@ -# spdlog - - -[![ci](https://github.com/gabime/spdlog/actions/workflows/linux.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/linux.yml)  -[![ci](https://github.com/gabime/spdlog/actions/workflows/windows.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/windows.yml)  -[![ci](https://github.com/gabime/spdlog/actions/workflows/macos.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/macos.yml)  -[![Build status](https://ci.appveyor.com/api/projects/status/d2jnxclg20vd0o50?svg=true&branch=v1.x)](https://ci.appveyor.com/project/gabime/spdlog) [![Release](https://img.shields.io/github/release/gabime/spdlog.svg)](https://github.com/gabime/spdlog/releases/latest) - -Fast C++ logging library - - -## Install -#### Header-only version -Copy the include [folder](https://github.com/gabime/spdlog/tree/v1.x/include/spdlog) to your build tree and use a C++11 compiler. - -#### Compiled version (recommended - much faster compile times) -```console -$ git clone https://github.com/gabime/spdlog.git -$ cd spdlog && mkdir build && cd build -$ cmake .. && cmake --build . -``` -see example [CMakeLists.txt](https://github.com/gabime/spdlog/blob/v1.x/example/CMakeLists.txt) on how to use. - -## Platforms -* Linux, FreeBSD, OpenBSD, Solaris, AIX -* Windows (msvc 2013+, cygwin) -* macOS (clang 3.5+) -* Android - -## Package managers: -* 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``` - - -## Features -* Very fast (see [benchmarks](#benchmarks) below). -* Headers only or compiled -* Feature-rich formatting, using the excellent [fmt](https://github.com/fmtlib/fmt) library. -* Asynchronous mode (optional) -* [Custom](https://github.com/gabime/spdlog/wiki/3.-Custom-formatting) formatting. -* Multi/Single threaded loggers. -* Various log targets: - * Rotating log files. - * Daily log files. - * Console logging (colors supported). - * syslog. - * Windows event log. - * Windows debugger (```OutputDebugString(..)```). - * Log to Qt widgets ([example](#log-to-qt-with-nice-colors)). - * Easily [extendable](https://github.com/gabime/spdlog/wiki/4.-Sinks#implementing-your-own-sink) with custom log targets. -* Log filtering - log levels can be modified at runtime as well as compile time. -* Support for loading log levels from argv or environment var. -* [Backtrace](#backtrace-support) support - store debug messages in a ring buffer and display them later on demand. - -## Usage samples - -#### Basic usage -```c++ -#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"); -} - -``` ---- -#### Create stdout/stderr logger object -```c++ -#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)"); -} -``` - ---- -#### Basic file logger -```c++ -#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; - } -} -``` ---- -#### Rotating files -```c++ -#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); -} -``` - ---- -#### Daily files -```c++ - -#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 support -```c++ -// 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).. -``` - ---- -#### Periodic flush -```c++ -// 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)); - -``` - ---- -#### Stopwatch -```c++ -// Stopwatch support for spdlog -#include "spdlog/stopwatch.h" -void stopwatch_example() -{ - spdlog::stopwatch sw; - spdlog::debug("Elapsed {}", sw); - spdlog::debug("Elapsed {:.3}", sw); -} - -``` - ---- -#### Log binary data in hex -```c++ -// 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)); -} - -``` - ---- -#### Logger with multi sinks - each with a different format and log level -```c++ - -// 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"); -} -``` - ---- -#### User-defined callbacks about log events -```c++ - -// 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 -} -``` - ---- -#### Asynchronous logging -```c++ -#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"); -} - -``` - ---- -#### Asynchronous logger with multi sinks -```c++ -#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); -} -``` - ---- -#### User-defined types -```c++ -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)); -} - -``` - ---- -#### User-defined flags in the log pattern -```c++ -// 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%$] %v"); - spdlog::set_formatter(std::move(formatter)); -} - -``` - ---- -#### Custom error handler -```c++ -void err_handler_example() -{ - // can be set globally or per logger(logger->set_error_handler(..)) - spdlog::set_error_handler([](const std::string &msg) { spdlog::get("console")->error("*** LOGGER ERROR ***: {}", msg); }); - spdlog::get("console")->info("some invalid message to trigger an error {}{}{}{}", 3); -} - -``` - ---- -#### syslog -```c++ -#include "spdlog/sinks/syslog_sink.h" -void syslog_example() -{ - std::string ident = "spdlog-example"; - auto syslog_logger = spdlog::syslog_logger_mt("syslog", ident, LOG_PID); - syslog_logger->warn("This is warning that will end up in syslog."); -} -``` ---- -#### Android example -```c++ -#include "spdlog/sinks/android_sink.h" -void android_example() -{ - std::string tag = "spdlog-android"; - auto android_logger = spdlog::android_logger_mt("android", tag); - android_logger->critical("Use \"adb shell logcat\" to view this message."); -} -``` - ---- -#### Load log levels from the env variable or argv - -```c++ -#include "spdlog/cfg/env.h" -int main (int argc, char *argv[]) -{ - spdlog::cfg::load_env_levels(); - // or specify the env variable name: - // MYAPP_LEVEL=info,mylogger=trace && ./example - // spdlog::cfg::load_env_levels("MYAPP_LEVEL"); - // or from the command line: - // ./example SPDLOG_LEVEL=info,mylogger=trace - // #include "spdlog/cfg/argv.h" // for loading levels from argv - // spdlog::cfg::load_argv_levels(argc, argv); -} -``` -So then you can: - -```console -$ export SPDLOG_LEVEL=info,mylogger=trace -$ ./example -``` - - ---- -#### Log file open/close event handlers -```c++ -// 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); -} -``` - ---- -#### Replace the Default Logger -```c++ -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"); -} -``` - ---- -#### Log to Qt with nice colors -```c++ -#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"); -} -``` ---- - -#### Mapped Diagnostic Context -```c++ -// 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"); -} -``` ---- -## Benchmarks - -Below are some [benchmarks](https://github.com/gabime/spdlog/blob/v1.x/bench/bench.cpp) done in Ubuntu 64 bit, Intel i7-4770 CPU @ 3.40GHz - -#### Synchronous mode -``` -[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 -``` -#### Asynchronous mode -``` -[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 - -``` - -## Documentation -Documentation can be found in the [wiki](https://github.com/gabime/spdlog/wiki/1.-QuickStart) pages. - ---- - -Thanks to [JetBrains](https://www.jetbrains.com/?from=spdlog) for donating product licenses to help develop **spdlog** - - +# spdlog + + +[![ci](https://github.com/gabime/spdlog/actions/workflows/linux.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/linux.yml)  +[![ci](https://github.com/gabime/spdlog/actions/workflows/windows.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/windows.yml)  +[![ci](https://github.com/gabime/spdlog/actions/workflows/macos.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/macos.yml)  +[![Build status](https://ci.appveyor.com/api/projects/status/d2jnxclg20vd0o50?svg=true&branch=v1.x)](https://ci.appveyor.com/project/gabime/spdlog) [![Release](https://img.shields.io/github/release/gabime/spdlog.svg)](https://github.com/gabime/spdlog/releases/latest) + +Fast C++ logging library + + +## Install +#### Header-only version +Copy the include [folder](https://github.com/gabime/spdlog/tree/v1.x/include/spdlog) to your build tree and use a C++11 compiler. + +#### Compiled version (recommended - much faster compile times) +```console +$ git clone https://github.com/gabime/spdlog.git +$ cd spdlog && mkdir build && cd build +$ cmake .. && cmake --build . +``` +see example [CMakeLists.txt](https://github.com/gabime/spdlog/blob/v1.x/example/CMakeLists.txt) on how to use. + +## Platforms +* Linux, FreeBSD, OpenBSD, Solaris, AIX +* Windows (msvc 2013+, cygwin) +* macOS (clang 3.5+) +* Android + +## Package managers: +* 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``` +* SPM: add `https://github.com/gabime/spdlog.git` as package dependency + +## Features +* Very fast (see [benchmarks](#benchmarks) below). +* Headers only or compiled +* Feature-rich formatting, using the excellent [fmt](https://github.com/fmtlib/fmt) library. +* Asynchronous mode (optional) +* [Custom](https://github.com/gabime/spdlog/wiki/3.-Custom-formatting) formatting. +* Multi/Single threaded loggers. +* Various log targets: + * Rotating log files. + * Daily log files. + * Console logging (colors supported). + * syslog. + * Windows event log. + * Windows debugger (```OutputDebugString(..)```). + * Log to Qt widgets ([example](#log-to-qt-with-nice-colors)). + * Easily [extendable](https://github.com/gabime/spdlog/wiki/4.-Sinks#implementing-your-own-sink) with custom log targets. +* Log filtering - log levels can be modified at runtime as well as compile time. +* Support for loading log levels from argv or environment var. +* [Backtrace](#backtrace-support) support - store debug messages in a ring buffer and display them later on demand. + +## Usage samples + +#### Basic usage +```c++ +#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"); +} + +``` +--- +#### Create stdout/stderr logger object +```c++ +#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)"); +} +``` + +--- +#### Basic file logger +```c++ +#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; + } +} +``` +--- +#### Rotating files +```c++ +#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); +} +``` + +--- +#### Daily files +```c++ + +#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 support +```c++ +// 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).. +``` + +--- +#### Periodic flush +```c++ +// 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)); + +``` + +--- +#### Stopwatch +```c++ +// Stopwatch support for spdlog +#include "spdlog/stopwatch.h" +void stopwatch_example() +{ + spdlog::stopwatch sw; + spdlog::debug("Elapsed {}", sw); + spdlog::debug("Elapsed {:.3}", sw); +} + +``` + +--- +#### Log binary data in hex +```c++ +// 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)); +} + +``` + +--- +#### Logger with multi sinks - each with a different format and log level +```c++ + +// 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"); +} +``` + +--- +#### User-defined callbacks about log events +```c++ + +// 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 +} +``` + +--- +#### Asynchronous logging +```c++ +#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"); +} + +``` + +--- +#### Asynchronous logger with multi sinks +```c++ +#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); +} +``` + +--- +#### User-defined types +```c++ +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)); +} + +``` + +--- +#### User-defined flags in the log pattern +```c++ +// 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%$] %v"); + spdlog::set_formatter(std::move(formatter)); +} + +``` + +--- +#### Custom error handler +```c++ +void err_handler_example() +{ + // can be set globally or per logger(logger->set_error_handler(..)) + spdlog::set_error_handler([](const std::string &msg) { spdlog::get("console")->error("*** LOGGER ERROR ***: {}", msg); }); + spdlog::get("console")->info("some invalid message to trigger an error {}{}{}{}", 3); +} + +``` + +--- +#### syslog +```c++ +#include "spdlog/sinks/syslog_sink.h" +void syslog_example() +{ + std::string ident = "spdlog-example"; + auto syslog_logger = spdlog::syslog_logger_mt("syslog", ident, LOG_PID); + syslog_logger->warn("This is warning that will end up in syslog."); +} +``` +--- +#### Android example +```c++ +#include "spdlog/sinks/android_sink.h" +void android_example() +{ + std::string tag = "spdlog-android"; + auto android_logger = spdlog::android_logger_mt("android", tag); + android_logger->critical("Use \"adb shell logcat\" to view this message."); +} +``` + +--- +#### Load log levels from the env variable or argv + +```c++ +#include "spdlog/cfg/env.h" +int main (int argc, char *argv[]) +{ + spdlog::cfg::load_env_levels(); + // or specify the env variable name: + // MYAPP_LEVEL=info,mylogger=trace && ./example + // spdlog::cfg::load_env_levels("MYAPP_LEVEL"); + // or from the command line: + // ./example SPDLOG_LEVEL=info,mylogger=trace + // #include "spdlog/cfg/argv.h" // for loading levels from argv + // spdlog::cfg::load_argv_levels(argc, argv); +} +``` +So then you can: + +```console +$ export SPDLOG_LEVEL=info,mylogger=trace +$ ./example +``` + + +--- +#### Log file open/close event handlers +```c++ +// 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); +} +``` + +--- +#### Replace the Default Logger +```c++ +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"); +} +``` + +--- +#### Log to Qt with nice colors +```c++ +#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"); +} +``` +--- + +#### Mapped Diagnostic Context +```c++ +// 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"); +} +``` +--- +## Benchmarks + +Below are some [benchmarks](https://github.com/gabime/spdlog/blob/v1.x/bench/bench.cpp) done in Ubuntu 64 bit, Intel i7-4770 CPU @ 3.40GHz + +#### Synchronous mode +``` +[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 +``` +#### Asynchronous mode +``` +[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 + +``` + +## Documentation +Documentation can be found in the [wiki](https://github.com/gabime/spdlog/wiki/1.-QuickStart) pages. + +--- + +Thanks to [JetBrains](https://www.jetbrains.com/?from=spdlog) for donating product licenses to help develop **spdlog** + +