Logger Class Reference

Detailed Description

A logger class implementation.

Logger will dump all messages to a sink (SinkBase) which will be in charge of serializing the messages to the appropriate channel. By default, Sink implementation is used.

It provides six different log levels, logger::level , which can be filtered based on the severity of the message.

Comments about the design:

• Given that fmt library is used to format the message to be logged it was consider neccesary not to expose the dependency in the header file and narrow it only to the implementation. That is why type-erasure was taken into account within Logger::log() method.
• Within Logger::log() method the variadic arguments are unpacked and serialized using a functor Serialize . The alternative to the functor is to use a lambda expresion, but there is a bug in gcc that is not fixed until 8.1 version.

  See also

  GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85305.

• Another way to do type-erasure is using std::any to allocate the variadic arguments, but this idea was dismissed given that it wouldn't allow the logger to manage all kind of types, due to the fact that an overload of any_cast<T>() for each new type to be serialized would be required.

  See also

  StackOverflow thread: https://stackoverflow.com/questions/56517207/implementing-pimpl-based-wrapper-around-a-class-using-variadic-template-function

#include <include/maliput/common/logger.h>

Public Member Functions
	MALIPUT_NO_COPY_NO_MOVE_NO_ASSIGN (Logger)
	Logger ()=default
template<typename... Args>
void	trace (const Args &... args)
	Log the message showing trace level prefix. More...
template<typename... Args>
void	debug (const Args &... args)
	Log the message showing debug level prefix. More...
template<typename... Args>
void	info (const Args &... args)
	Log the message showing info level prefix. More...
template<typename... Args>
void	warn (const Args &... args)
	Log the message showing warning level prefix. More...
template<typename... Args>
void	error (const Args &... args)
	Log the message showing error level prefix. More...
template<typename... Args>
void	critical (const Args &... args)
	Log the message showing critical level prefix. More...
void	set_sink (std::unique_ptr< common::SinkBase > sink)
	Set a sink. More...
SinkBase *	get_sink ()
	Get the current sink. More...
std::string	set_level (logger::level log_level)
	Sets the minimum level of messages to be logged. More...

Static Public Attributes
static constexpr int	kNumberOfArguments {100}
	Indicates the maximum number of arguments that a single log command is able to process. More...

Related Functions
(Note that these are not member functions.)
std::string	set_log_level (const std::string &level)
	Invokes maliput::log()->set_level(level). More...
common::Logger *	log ()
	Retrieve an instance of a logger to use for logger. More...

Constructor & Destructor Documentation

Logger()

Logger ( )

default

Member Function Documentation

get_sink()

SinkBase* get_sink

(

)

Get the current sink.

Returns

A pointer to the current sink.

MALIPUT_NO_COPY_NO_MOVE_NO_ASSIGN()

MALIPUT_NO_COPY_NO_MOVE_NO_ASSIGN

(

Logger

)

set_level()

std::string set_level

(

logger::level

log_level

)

Sets the minimum level of messages to be logged.

Parameters

log_level

Must be a level enum value from the level enumerations: trace, debug, info, warning, error, critical or off.

Returns

The string value of the previous log level.

See also

logger::kLevelToString.

set_sink()

void set_sink

(

std::unique_ptr< common::SinkBase >

sink

)

Set a sink.

Parameters

sink	Is a SinkBase implementation.

Exceptions

common::assertion_error

When sink is nullptr.

Friends And Related Function Documentation

log()

common::Logger * log ( )

related

Retrieve an instance of a logger to use for logger.

See Logger.

set_log_level()

std::string set_log_level ( const std::string &  level )

related

Invokes maliput::log()->set_level(level).

See Logger.

Parameters

level

Must be a string from the level enumerations: trace, debug, info, warning, error, critical or off.

Returns

The string value of the previous log level.

Exceptions

std::out_of_range

When level is not one of the predefined values.

Member Data Documentation

kNumberOfArguments

constexpr int kNumberOfArguments {100}

staticconstexpr

Indicates the maximum number of arguments that a single log command is able to process.

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

• logger.h
• logger.cc