357 lines
12 KiB
Markdown
357 lines
12 KiB
Markdown
# spdlog
|
|
|
|
Very fast, header-only/compiled, C++ logging library. [](https://travis-ci.org/gabime/spdlog) [](https://ci.appveyor.com/project/gabime/spdlog)
|
|
|
|
|
|
|
|
## Install
|
|
#### Header only version
|
|
Copy the source [folder](https://github.com/gabime/spdlog/tree/v1.x/include/spdlog) to your build tree and use a C++11 compiler.
|
|
|
|
#### Static lib version (recommended - much faster compile times, v1.4.0)
|
|
```console
|
|
$ git clone https://github.com/gabime/spdlog.git
|
|
$ cd spdlog && mkdir build && cd build
|
|
$ cmake .. && make -j
|
|
```
|
|
|
|
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:
|
|
* Homebrew: `brew install spdlog`
|
|
* FreeBSD: `cd /usr/ports/devel/spdlog/ && make install clean`
|
|
* Fedora: `yum install spdlog`
|
|
* Gentoo: `emerge dev-libs/spdlog`
|
|
* Arch Linux: `yaourt -S spdlog-git`
|
|
* vcpkg: `vcpkg install spdlog`
|
|
|
|
## Features
|
|
* Very fast (see [benchmarks](#benchmarks) below).
|
|
* Headers only, just copy and use. Or use as a compiled library.
|
|
* Feature rich formatting, using the excellent [fmt](https://github.com/fmtlib/fmt) library.
|
|
* **New!** [Backtrace](#backtrace-support) support - store debug or other messages in a ring buffer and display later on demand.
|
|
* Fast 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 debugger (```OutputDebugString(..)```)
|
|
* Easily extendable with custom log targets (just implement a single function in the [sink](include/spdlog/sinks/sink.h) interface).
|
|
* Severity based filtering - threshold levels can be modified in runtime as well as in compile time.
|
|
|
|
|
|
## Usage samples
|
|
|
|
#### Basic usage
|
|
```c++
|
|
#include "spdlog/spdlog.h"
|
|
#include "spdlog/sinks/basic_file_sink.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
|
|
// define SPDLOG_ACTIVE_LEVEL to desired level
|
|
SPDLOG_TRACE("Some trace message with param {}", {});
|
|
SPDLOG_DEBUG("Some debug message");
|
|
|
|
// Set the default logger to file logger
|
|
auto file_logger = spdlog::basic_logger_mt("basic_logger", "logs/basic.txt");
|
|
spdlog::set_default_logger(file_logger);
|
|
}
|
|
```
|
|
#### create stdout/stderr logger object
|
|
```c++
|
|
#include "spdlog/spdlog.h"
|
|
#include "spdlog/sinks/stdout_color_sinks.h"
|
|
void stdout_example()
|
|
{
|
|
// create 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 my_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 5mb size max and 3 rotated files
|
|
auto rotating_logger = spdlog::rotating_logger_mt("some_logger_name", "logs/rotating.txt", 1048576 * 5, 3);
|
|
}
|
|
```
|
|
|
|
---
|
|
#### Daily files
|
|
```c++
|
|
|
|
#include "spdlog/sinks/daily_file_sink.h"
|
|
void daily_example()
|
|
{
|
|
// Create a daily logger - a new file is created every day on 2:30am
|
|
auto daily_logger = spdlog::daily_logger_mt("daily_logger", "logs/daily.txt", 2, 30);
|
|
}
|
|
|
|
```
|
|
|
|
---
|
|
#### Backtrace support
|
|
```c++
|
|
// Loggers can store in a ring buffer all messages (including debug/trace) and display later on demand.
|
|
// When needed, call dump_backtrace() to see them
|
|
spdlog::enable_backtrace(32); // create ring buffer with capacity of 32 messages
|
|
// 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!
|
|
spdlog::flush_every(std::chrono::seconds(3));
|
|
|
|
```
|
|
|
|
---
|
|
#### Log binary data in hex
|
|
```c++
|
|
// many types of std::container<char> 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 to lines.
|
|
|
|
#include "spdlog/fmt/bin_to_hex.h"
|
|
|
|
void binary_example()
|
|
{
|
|
auto console = spdlog::get("console");
|
|
std::array<char, 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));
|
|
}
|
|
|
|
```
|
|
|
|
---
|
|
#### Logger with multi sinks - each with different format and log level
|
|
```c++
|
|
|
|
// create 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<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::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");
|
|
}
|
|
```
|
|
|
|
---
|
|
#### 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<spdlog::async_factory>("async_file_logger", "logs/async_log.txt");
|
|
// alternatively:
|
|
// auto async_file = spdlog::create_async<spdlog::sinks::basic_file_sink_mt>("async_file_logger", "logs/async_log.txt");
|
|
}
|
|
|
|
```
|
|
|
|
---
|
|
#### Asynchronous logger with multi sinks
|
|
```c++
|
|
#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<spdlog::sinks::stdout_color_sink_mt >();
|
|
auto rotating_sink = std::make_shared<spdlog::sinks::rotating_file_sink_mt>("mylog.txt", 1024*1024*10, 3);
|
|
std::vector<spdlog::sink_ptr> sinks {stdout_sink, rotating_sink};
|
|
auto logger = std::make_shared<spdlog::async_logger>("loggername", sinks.begin(), sinks.end(), spdlog::thread_pool(), spdlog::async_overflow_policy::block);
|
|
spdlog::register_logger(logger);
|
|
}
|
|
```
|
|
|
|
---
|
|
#### User defined types
|
|
```c++
|
|
// user defined types logging by implementing operator<<
|
|
#include "spdlog/fmt/ostr.h" // must be included
|
|
struct my_type
|
|
{
|
|
int i;
|
|
template<typename OStream>
|
|
friend OStream &operator<<(OStream &os, const my_type &c)
|
|
{
|
|
return os << "[my_type i=" << c.i << "]";
|
|
}
|
|
};
|
|
|
|
void user_defined_example()
|
|
{
|
|
spdlog::get("console")->info("user defined type: {}", my_type{14});
|
|
}
|
|
|
|
```
|
|
---
|
|
#### 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.");
|
|
}
|
|
```
|
|
|
|
## 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 sharing same logger, 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] Total iters : 3
|
|
[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.
|