Logger Class Reference

#include <Logger.h>

Public Member Functions
	Logger (LogLevel level, LogSink *sink)
	~Logger ()
bool	shouldLog (const LogCategory &category, LogLevel level) const
template<class... Args>
void	log (const LogCategory &category, LogLevel level, fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	trace (const LogCategory &category, fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	debug (const LogCategory &category, fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	info (const LogCategory &category, fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	warning (const LogCategory &category, fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	error (const LogCategory &category, fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	critical (const LogCategory &category, fmt::format_string< Args... > fmt, Args &&... args)
bool	shouldLog (LogLevel level) const
template<class... Args>
void	log (LogLevel level, fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	trace (fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	debug (fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	info (fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	warning (fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	error (fmt::format_string< Args... > fmt, Args &&... args)
template<class... Args>
void	critical (fmt::format_string< Args... > fmt, Args &&... args)
LogLevel	level () const
void	setLevel (LogLevel level)
std::optional< LogLevel >	level (const LogCategory &category) const
void	setLevel (LogCategory &category, std::optional< LogLevel > level)
LogSink *	sink () const
void	setSink (LogSink *sink)

Private Member Functions
void	logV (const LogCategory &category, LogLevel level, fmt::string_view fmt, fmt::format_args args)

Private Attributes
std::mutex	_mutex
LogCategory	_defaultCategory = LogCategory({})
LogSink *	_sink = nullptr

Detailed Description

Main logging class.

Logger is a singleton, but the user is supposed to create a Logger instance himself before using it. This would usually be done in the first few lines of main.

Some notes on design decisions:

1. Logger supports hooking into other logging frameworks, translating the log levels appropriately. Thus, it's possible to create separate LogCategory instances for SDL and FFmpeg logs, and manage log levels through the Logger interface. Setting global log level to LOG_CRITICAL will then prevent both SDL and FFmpeg from emitting any non-critical log messages - the important point being that they will be filtered out at SDL/FFmpeg level, and not in the Logger code.
2. Point (1) above led to settling on making Logger a singleton. This is what pretty much all other logging libraries do, and thus supporting both multiple Logger instances AND being able to hook into external logging frameworks made very little sense.
3. This also made it possible to implement log categories efficiently by storing per-category log levels inside the LogCategory objects.
4. Different logging targets are implemented with the LogSink interface. LogSink also makes it possible to implement complex logging logic, i.e. writing all logs starting with LOG_DEBUG into a file, but printing only errors to the console. It's up to the user to properly implement the log level handling in this case.

Constructor & Destructor Documentation

Logger()

Logger::Logger ( LogLevel  level, LogSink *  sink  )

explicit

~Logger()

Logger::~Logger

(

)

Member Function Documentation

critical() [1/2]

template<class... Args>

void Logger::critical ( const LogCategory &  category, fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

critical() [2/2]

template<class... Args>

void Logger::critical ( fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

debug() [1/2]

template<class... Args>

void Logger::debug ( const LogCategory &  category, fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

debug() [2/2]

template<class... Args>

void Logger::debug ( fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

error() [1/2]

template<class... Args>

void Logger::error ( const LogCategory &  category, fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

error() [2/2]

template<class... Args>

void Logger::error ( fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

info() [1/2]

template<class... Args>

void Logger::info ( const LogCategory &  category, fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

info() [2/2]

template<class... Args>

void Logger::info ( fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

level() [1/2]

LogLevel Logger::level

(

)

const

level() [2/2]

std::optional< LogLevel > Logger::level

(

const LogCategory &

category

)

const

log() [1/2]

template<class... Args>

void Logger::log ( const LogCategory &  category, LogLevel  level, fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

log() [2/2]

template<class... Args>

void Logger::log ( LogLevel  level, fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

logV()

void Logger::logV ( const LogCategory &  category, LogLevel  level, fmt::string_view  fmt, fmt::format_args  args  )

private

setLevel() [1/2]

void Logger::setLevel	(	LogCategory &	category,
		std::optional< LogLevel >	level
	)

setLevel() [2/2]

void Logger::setLevel

(

LogLevel

level

)

setSink()

void Logger::setSink

(

LogSink *

sink

)

shouldLog() [1/2]

bool Logger::shouldLog ( const LogCategory &  category, LogLevel  level  ) const

inline

shouldLog() [2/2]

bool Logger::shouldLog ( LogLevel  level ) const

inline

sink()

LogSink * Logger::sink

(

)

const

trace() [1/2]

template<class... Args>

void Logger::trace ( const LogCategory &  category, fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

trace() [2/2]

template<class... Args>

void Logger::trace ( fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

warning() [1/2]

template<class... Args>

void Logger::warning ( const LogCategory &  category, fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

warning() [2/2]

template<class... Args>

void Logger::warning ( fmt::format_string< Args... >  fmt, Args &&...  args  )

inline

Member Data Documentation

_defaultCategory

LogCategory Logger::_defaultCategory = LogCategory({})

private

_mutex

std::mutex Logger::_mutex

private

_sink

LogSink* Logger::_sink = nullptr

private

---

The documentation for this class was generated from the following files:

• src/Library/Logger/Logger.h
• src/Library/Logger/Logger.cpp