{"name":"spdlog","tagline":"Super fast C++ logging library.","body":"# spdlog\r\n\r\nVery fast, header only, C++ logging library.\r\n\r\n## Install\r\nJust copy the files to your build tree and use a C++11 compiler\r\n\r\n## Tested on:\r\n* gcc 4.8.1 and above\r\n* clang 3.5 (Linux and OSX)\r\n* visual studio 2013\r\n* mingw with g++ 4.9.x\r\n\r\n##Features\r\n* Very fast - performance is the primary goal (see [benchmarks](#benchmarks) below).\r\n* Headers only.\r\n* No dependencies - just copy and use.\r\n* Cross platform - Linux / Windows on 32/64 bits.\r\n* **new!** Feature rich [call style](#usage-example) using the excellent [cppformat](http://cppformat.github.io/) library.\r\n* ostream call style is supported too.\r\n* Extremely fast asynchronous mode (optional) - using lockfree queues and other tricks to reach millions of calls/sec.\r\n* [Custom](https://github.com/gabime/spdlog/wiki/Custom-formatting) formatting.\r\n* Multi/Single threaded loggers.\r\n* Various log targets:\r\n * Rotating log files.\r\n * Daily log files.\r\n * Console logging.\r\n * Linux syslog.\r\n * Easily extendable with custom log targets (just implement a single function in the [sink](include/spdlog/sinks/sink.h) interface).\r\n* Severity based filtering - threshold levels can be modified in runtime as well as in compile time.\r\n\r\n\r\n\r\n## Benchmarks\r\n\r\nBelow are some [benchmarks](bench) comparing popular log libraries under Ubuntu 64 bit, Intel i7-4770 CPU @ 3.40GHz \r\n\r\n#### Synchronous mode\r\nTime needed to log 1,000,000 lines in synchronous mode (in seconds, the best of 3 runs):\r\n\r\n|threads|boost log|glog |easylogging |spdlog|\r\n|-------|:-------:|:-----:|----------:|------:|\r\n|1| 4.169s |1.066s |0.975s |0.302s|\r\n|10| 16.029 |3.032s |2.857s |0.968s|\r\n|100| 15.008 |1.139s |4.512s |0.497s|\r\n\r\n\r\n#### Asynchronous mode \r\nTime needed to log 1,000,000 lines in asynchronous mode, i.e. the time it takes to put them in the async queue (in seconds, the best of 3 runs):\r\n\r\n|threads|g2log <sup>async logger</sup> |spdlog <sup>async mode</sup>|\r\n|:-------|:-----:|-------------------------:|\r\n|1| 1.850s |0.216s |\r\n|10| 0.943s |0.173s|\r\n|100| 0.959s |0.202s|\r\n\r\n\r\n\r\n\r\n## Usage Example\r\n```c++\r\n#include <iostream>\r\n#include \"spdlog/spdlog.h\"\r\n\r\nint main(int, char* [])\r\n{\r\n namespace spd = spdlog;\r\n try\r\n {\r\n //Create console, multithreaded logger\r\n auto console = spd::stdout_logger_mt(\"console\");\r\n console->info(\"Welcome to spdlog!\") ;\r\n console->info(\"An info message example {}..\", 1);\r\n console->info() << \"Streams are supported too \" << 1;\r\n\t\r\n //Formatting examples\r\n console->info(\"Easy padding in numbers like {:08d}\", 12);\r\n console->info(\"Support for int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b}\", 42);\r\n console->info(\"Support for floats {:03.2f}\", 1.23456);\r\n console->info(\"Positional args are {1} {0}..\", \"too\", \"supported\");\r\n\r\n console->info(\"{:<30}\", \"left aligned\");\r\n console->info(\"{:>30}\", \"right aligned\");\r\n console->info(\"{:^30}\", \"centered\");\r\n \r\n //\r\n // Runtime log levels\r\n //\r\n spd::set_level(spd::level::info); //Set global log level to info\r\n console->debug(\"This message shold not be displayed!\");\r\n console->set_level(spd::level::debug); // Set specific logger's log level\r\n console->debug(\"Now it should..\");\r\n \r\n //\r\n // Create a file rotating logger with 5mb size max and 3 rotated files\r\n //\r\n auto file_logger = spd::rotating_logger_mt(\"file_logger\", \"logs/mylogfile\", 1048576 * 5, 3);\r\n for(int i = 0; i < 10; ++i)\r\n\t\t file_logger->info(\"{} * {} equals {:>10}\",i,i,i*i);\r\n\r\n//\r\n // Create a daily logger - a new file is created every day on 2:30am\r\n //\r\n a
