Logging

Macros
#define	ndsLogStream(node, logLevel)   if(!(node).isLogLevelEnabled(logLevel)) {} else (node).getLogger(logLevel)
	If the logging is enabled for the specified severity level then the macro returns the proper logging stream, otherwise it skips the logging operation.
#define	ndsDebugStream(node)   ndsLogStream(node, nds::logLevel_t::debug)
	Log to the debug stream if the debug log level is enabled on the selected node. More...
#define	ndsInfoStream(node)   ndsLogStream(node, nds::logLevel_t::info)
	Log to the info stream if the info log level is enabled on the selected node. More...
#define	ndsWarningStream(node)   ndsLogStream(node, nds::logLevel_t::warning)
	Log to the warning stream if the warning log level is enabled on the selected node. More...
#define	ndsErrorStream(node)   ndsLogStream(node, nds::logLevel_t::error)
	Log to the error stream if the error log level is enabled on the selected node. More...

Enumerations
enum	nds::logLevel_t : std::uint8_t {   nds::logLevel_t::debug, nds::logLevel_t::info, nds::logLevel_t::warning, nds::logLevel_t::error,   nds::logLevel_t::none }
	Defines the severities of the log information. More...

Functions
std::ostream &	nds::Base::getLogger (const logLevel_t logLevel)
	Retrieve a logging stream for the specified log level. More...
bool	nds::Base::isLogLevelEnabled (const logLevel_t logLevel) const
	Returns true if the logging for a particular severity level has been enabled. More...
void	nds::Base::setLogLevel (const logLevel_t logLevel)
	Enable the logging for a particular severity level. More...
std::ostream &	nds::BaseImpl::getLogger (const logLevel_t logLevel)
	Retrieve a stream that can be used for logging. More...
bool	nds::BaseImpl::isLogLevelEnabled (const logLevel_t logLevel) const
	Returns true if the logging for a particular severity level has been enabled. More...
virtual void	nds::BaseImpl::setLogLevel (const logLevel_t logLevel)
	Enable the logging for a particular severity level. More...

Detailed Description

The Logging methods can be used to send debug, information, warning or errors to the control system.

The logging interface is control-system agnostic.

Each logged information is tied to a node, and the log level of each node can be set separately. For instance, it is possible to have the whole device (root node) with a log level set to "warning" and only a specific state machine set to "debug".

The logging level of each node can be set with Base::setLogLevel().

Each node provides a different std::ostream object for each severity level and for each thread. Your application can retrieve the std::ostream object by using Base::getLogger().

Warning

Altought it is possible to use directly Base::getLogger() in order to perform the log operations, the suggested method is the usage of the logging macros ndsDebugStream, ndsInfoStream, ndsWarningStream and ndsErrorStream.

The loggin macros boost the performances by avoiding the log altogheter when it is not necessary

Macro Definition Documentation

#define ndsDebugStream

(

node

)

ndsLogStream(node, nds::logLevel_t::debug)

Log to the debug stream if the debug log level is enabled on the selected node.

The last logged element must be std::endl.

Example:

ndsDebugStream(node) << "The value has been changed from " << value0 << " to value " << value1 << std::endl

#define ndsErrorStream

(

node

)

ndsLogStream(node, nds::logLevel_t::error)

Log to the error stream if the error log level is enabled on the selected node.

The last logged element must be std::endl.

Example:

ndsErrorStream(node) << "An error has occurred while updating the value to " << value << std::endl

#define ndsInfoStream

(

node

)

ndsLogStream(node, nds::logLevel_t::info)

Log to the info stream if the info log level is enabled on the selected node.

The last logged element must be std::endl.

Example:

ndsInfoStream(node) << "The value has been changed from " << value0 << " to value " << value1 << std::endl

#define ndsWarningStream

(

node

)

ndsLogStream(node, nds::logLevel_t::warning)

Log to the warning stream if the warning log level is enabled on the selected node.

The last logged element must be std::endl.

Example:

ndsWarningStream(node) << "The value could not be changed from " << value0 << " to " << value1 << std::endl

Enumeration Type Documentation

enum nds::logLevel_t : std::uint8_t

strong

Defines the severities of the log information.

Enumerator
debug	Debug information.
info	Non critical information.
warning	Warning.
error	Error.
none	Nothing is logger.

Function Documentation

std::ostream& nds::BaseImpl::getLogger

(

const logLevel_t

logLevel

)

Retrieve a stream that can be used for logging.

Logging streams are specific for the requested log level and the current thread.

Parameters

logLevel

the severity level of the messages that will be logged througn the stream

Returns

a logging stream for the requested log level in the current thread

std::ostream& nds::Base::getLogger

(

const logLevel_t

logLevel

)

Retrieve a logging stream for the specified log level.

You should use the NDS macros ndsDebugStream, ndsInfoStream, ndsWarningStream and ndsErrorStream in order to perform log operations: this increases the performances by avoiding non-necessary operations if the log has been disabled.

The log information must be terminated by std::endl.

Log streams are specific for each running thread in order to avoid multithreading related issues.

Example of usage:

node.getLogger(nds::logLevel_t::warning) << "This is a warning message" << std::endl;

or the preferred way:

ndsWarningStream(node) << "This is the warning n." << 10 << std::endl;

Parameters

logLevel

the level of the messages that will be logged to the stream

Returns

a stream to which your application can send log messages. Log messages must be terminated by std::endl

bool nds::BaseImpl::isLogLevelEnabled

(

const logLevel_t

logLevel

)

const

Returns true if the logging for a particular severity level has been enabled.

Parameters

logLevel

the severity level for which the status is required

Returns

true if the logging for the specified severity level is enabled

bool nds::Base::isLogLevelEnabled

(

const logLevel_t

logLevel

)

const

Returns true if the logging for a particular severity level has been enabled.

Parameters

logLevel

the severity level for which the status is required

Returns

true if the logging for the specified severity level is enabled

virtual void nds::BaseImpl::setLogLevel ( const logLevel_t  logLevel )

virtual

Enable the logging for a particular severity level.

Parameters

logLevel

the severity level for which the logging is enabled.

void nds::Base::setLogLevel

(

const logLevel_t

logLevel

)

Enable the logging for a particular severity level.

The logging severity level will be set also on the node's children.

Parameters

logLevel

the severity level for which the logging is enabled.