114 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			114 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
# spdlog
 | 
						|
 | 
						|
Very fast, header only, C++ logging library.
 | 
						|
 | 
						|
## Install
 | 
						|
Just copy the files to your build tree and use a C++11 compiler
 | 
						|
 | 
						|
## Tested on:
 | 
						|
* gcc 4.8.1 and above
 | 
						|
* clang 3.5
 | 
						|
* visual studio 2013
 | 
						|
* mingw with g++ 4.9.x
 | 
						|
 | 
						|
##Features
 | 
						|
* Very fast - performance is the primary goal (see [becnhmarks](#benchmarks) below).
 | 
						|
* Headers only.
 | 
						|
* No dependencies.
 | 
						|
* Cross platform - Linux / Windows on 32/64 bits.
 | 
						|
* **new!** Feature rich cppfromat [call style](http://cppformat.readthedocs.org/en/stable/syntax.html) using the excellent [cppformat](http://cppformat.github.io/) library.
 | 
						|
* Example: ```logger.info("Hello {} {:08x}!!", "world", 42);```
 | 
						|
* ostream call style: ```logger.info() << "Hello << "logger";```
 | 
						|
* **new!** Optional, extremly fast asynchronous mode using lockfree queues, pre allocated memory and deffered formatting.
 | 
						|
* [Custom](https://github.com/gabime/spdlog/wiki/Custom-formatting) formatting.
 | 
						|
* Multi/Single threaded loggers.
 | 
						|
* Various log targets:
 | 
						|
    * Rotating log files.
 | 
						|
    * Daily log files.
 | 
						|
    * Console logging.
 | 
						|
    * Linux syslog.
 | 
						|
    * Easily extendable with custom log targets  (just implement a single function in the [sink](include/spdlog/sinks/sink.h) interface).
 | 
						|
* Severity based filtering - can be modified in runtime.
 | 
						|
 | 
						|
 | 
						|
 | 
						|
## Benchmarks
 | 
						|
 | 
						|
Below are some [benchmarks](bench) comparing the time needed to log 1,000,000 lines to file under Ubuntu 64 bit, Intel i7-4770 CPU @ 3.40GHz (the best of 3 runs for each logger):
 | 
						|
 | 
						|
|threads|boost log|glog|g2log <sup>async mode</sup>|spdlog|spdlog <sup>async mode</sup>|
 | 
						|
|-------|:-------:|:-----:|------:|------:|------:|
 | 
						|
|1|4.779s|1.109s|3.155s|0.319s|0.212s
 | 
						|
|10|15.151ss|3.546s|3.500s|0.641s|0.199s|
 | 
						|
 | 
						|
 | 
						|
## Usage Example
 | 
						|
```c++
 | 
						|
#include <iostream>
 | 
						|
#include "spdlog/spdlog.h"
 | 
						|
 | 
						|
int main(int, char* [])
 | 
						|
{
 | 
						|
    namespace spd = spdlog;
 | 
						|
    try
 | 
						|
    {
 | 
						|
        std::string filename = "logs/spdlog_example";
 | 
						|
        // Set log level to all loggers to DEBUG and above
 | 
						|
        spd::set_level(spd::level::DEBUG);
 | 
						|
 | 
						|
        //Create console, multithreaded logger
 | 
						|
        auto console = spd::stdout_logger_mt("console");
 | 
						|
        console->info("Welcome to spdlog!") ;
 | 
						|
        console->info("An info message example {}..", 1);
 | 
						|
        console->info() << "Streams are supported too  " << 1;
 | 
						|
 | 
						|
        console->info("Easy padding in numbers like {:08d}", 12);
 | 
						|
        console->info("Support for int: {0:d};  hex: {0:x};  oct: {0:o}; bin: {0:b}", 42);
 | 
						|
        console->info("Support for floats {:03.2f}", 1.23456);
 | 
						|
        console->info("Positional args are {1} {0}..", "too", "supported");
 | 
						|
 | 
						|
        console->info("{:<30}", "left aligned");
 | 
						|
        console->info("{:>30}", "right aligned");
 | 
						|
        console->info("{:^30}", "centered");
 | 
						|
        
 | 
						|
        //See cppformat syntax documation here:
 | 
						|
        //http://cppformat.readthedocs.org/en/stable/syntax.html
 | 
						|
        
 | 
						|
        //Create a file rotating logger with 5mb size max and 3 rotated files
 | 
						|
        auto file_logger = spd::rotating_logger_mt("file_logger", filename, 1024 * 1024 * 5, 3);
 | 
						|
        file_logger->info("Log file message number", 1);
 | 
						|
        for(int i = 0; i < 10; ++i)
 | 
						|
		      file_logger->info("{} * {} equals {:>10}", i, i, i*i);
 | 
						|
 | 
						|
        spd::set_pattern("*** [%H:%M:%S %z] [thread %t] %v ***");
 | 
						|
        file_logger->info("This is another message with custom format");
 | 
						|
 | 
						|
        spd::get("console")->info("loggers can be retrieved from a global registry using the spdlog::get(logger_name) function");
 | 
						|
 | 
						|
        SPDLOG_TRACE(file_logger, "This is a trace message (only #ifdef _DEBUG)", 123);
 | 
						|
 | 
						|
        //
 | 
						|
        // Asynchronous logging is easy..
 | 
						|
        // Just call spdlog::set_async_mode(max_q_size) and all created loggers from now on will be asynchronous..
 | 
						|
        //
 | 
						|
        size_t q_size = 1048576; //queue size must be power of 2
 | 
						|
        spdlog::set_async_mode(q_size);
 | 
						|
        auto async_file= spd::daily_logger_st("async_file_logger", "logs/async_log.txt");
 | 
						|
        async_file->info() << "This is async log.." << "Should be very fast!";
 | 
						|
        
 | 
						|
        //
 | 
						|
        // syslog example
 | 
						|
        //
 | 
						|
#ifdef __linux__
 | 
						|
        auto syslog_logger = spd::syslog_logger("syslog");
 | 
						|
        syslog_logger->warn("This is warning that will end up in syslog. This is Linux only!");
 | 
						|
#endif
 | 
						|
    }
 | 
						|
    catch (const spd::spdlog_ex& ex)
 | 
						|
    {
 | 
						|
        std::cout << "Log failed: " << ex.what() << std::endl;
 | 
						|
    }
 | 
						|
}
 | 
						|
 | 
						|
```
 |