GLogger Class Reference

Handles structured logging with verbosity and debug levels. More...

#include <glogger.h>

Public Member Functions
	GLogger (const std::shared_ptr< GOptions > &gopts, const std::string &cname, const std::string &lname="")
	Constructs a GLogger instance and resolves its runtime configuration.
	GLogger ()=default
	Default constructor.
	~GLogger ()
	Destructor.
template<typename... Args>
void	debug (debug_type type, Args &&... args) const
	Logs a debug message if the debug level is nonzero.
template<typename... Args>
void	info (int level, Args &&... args) const
	Logs an informational message, optionally gated by verbosity level.
template<typename... Args>
void	info (Args &&... args) const
	Convenience overload of info() that defaults to level 0.
template<typename... Args>
void	warning (Args &&... args) const
	Logs a warning message.
template<typename... Args>
void	error (int exit_code, Args &&... args) const
	Logs an error message and terminates the process.
template<typename... Args>
void	critical (Args &&... args) const
	Logs a critical message.
std::string	get_class_name () const
	Returns the caller-provided class name associated with this logger instance.

Detailed Description

GLogger centralizes formatted output for simulation components. Messages are emitted to the Geant4 streams (G4cout/G4cerr) and can be filtered based on configuration obtained from GOptions.

Key responsibilities:

• Apply verbosity/debug filtering consistently across the codebase.
• Render standardized message headers including a per-instance atomic counter.
• Provide convenience APIs that accept variadic "streamable" arguments, allowing callers to build messages without manual string formatting.

Filtering model

• Debug messages are emitted only when the resolved debug level is nonzero.
• Info messages can be emitted at level 0, 1, or 2, each gated by the resolved verbosity level.
• Warning and critical messages are always emitted.
• Error messages are emitted and then the process terminates with an exit code.

Warning

This class writes to shared output streams. While the internal counter is thread-safe, output interleaving is still possible depending on the underlying stream behavior.

Definition at line 84 of file glogger.h.

Constructor & Destructor Documentation

GLogger() [1/2]

GLogger::GLogger ( const std::shared_ptr< GOptions > & gopts, const std::string & cname, const std::string & lname = "" )

inlineexplicit

The constructor queries the provided GOptions to resolve:

• The verbosity level associated with lname.
• The debug level associated with lname.

It also emits a constructor-style debug message via debug() (only if debug is enabled for this logger name).

Parameters

gopts	Shared pointer to the GOptions instance used for verbosity/debug lookup.
cname	Caller-provided class name (informational; currently not used for filtering).
lname	The logger name (subsystem identifier). This is used as the lookup key in GOptions.

Definition at line 102 of file glogger.h.

GLogger() [2/2]

GLogger::GLogger ( )

default

This constructor does not resolve verbosity/debug settings and leaves the logger in a default-initialized state. It is primarily useful for scenarios where a logger instance must exist before configuration is available.

Note

If you use this constructor, ensure logger_name, verbosity_level, and debug_level are set through the normal construction path before relying on filtering behavior.

~GLogger()

GLogger::~GLogger ( )

inline

Emits a destructor-style debug message via debug() (only if debug is enabled).

Definition at line 130 of file glogger.h.

Member Function Documentation

critical()

template<typename... Args>

void GLogger::critical ( Args &&... args ) const

inline

Critical messages are always printed and are intended for high-visibility output that should stand out (for example : major state transitions, run headers, or emphasized notices).

Template Parameters

Args	Variadic template parameters for any streamable types.

Parameters

args	Message parts to be logged.

Definition at line 268 of file glogger.h.

debug()

template<typename... Args>

void GLogger::debug ( debug_type type, Args &&... args ) const

inline

This method builds a single message string from args... using stream insertion into an std::ostringstream. It then prints the message with a standardized header and optional constructor/destructor markers depending on type.

Template Parameters

Args	Variadic template parameters representing any streamable types.

Parameters

type	The debug message classification : NORMAL, CONSTRUCTOR, or DESTRUCTOR.
args	The message components. Each argument must be insertable into std::ostream.

Implementation techniques used:

• Variadic templates for a flexible number of message components.
• Perfect forwarding (std::forward) to preserve value categories.
• Fold expression (oss << ... << arg) to stream all arguments.

Note

Debug output is suppressed entirely when debug_level == 0.

Definition at line 151 of file glogger.h.

error()

template<typename... Args>

void GLogger::error ( int exit_code, Args &&... args ) const

inline

This method prints:

• The provided message.
• The explicit exit code line.

Then it terminates the process via std::exit(exit_code).

Template Parameters

Args	Variadic template parameters for any streamable types.

Parameters

exit_code	The program exit code to return to the calling environment.
args	Message parts to be logged before exiting.

Note

This function is marked [[noreturn]] because it always terminates the process.

Definition at line 250 of file glogger.h.

get_class_name()

std::string GLogger::get_class_name ( ) const

inline

This value is currently informational and can be used by callers to include the originating class in their own message composition if desired.

Returns

The stored class name string.

Definition at line 282 of file glogger.h.

info() [1/2]

template<typename... Args>

void GLogger::info ( Args &&... args ) const

inline

This overload is intended for the most common informational messages that should always be printed irrespective of verbosity configuration.

Template Parameters

Args	Variadic template parameters for any streamable types.

Parameters

args	Streamable message components.

Definition at line 214 of file glogger.h.

info() [2/2]

template<typename... Args>

void GLogger::info ( int level, Args &&... args ) const

inline

Info messages support three levels of detail:

• level 0 : Always printed (baseline information).
• level 1 : Printed only when verbosity_level > 0.
• level 2 : Printed only when verbosity_level > 1 (most detailed).

Template Parameters

Args	Variadic template parameters for any streamable types.

Parameters

level	The info importance/detail level (0, 1, or 2).
args	Message components to log. Each argument must be stream-insertable.

Exceptions

(process

termination) If level is not 0, 1, or 2, this method prints a fatal error and terminates the process with EC_WRONG_VERBOSITY_LEVEL.

Definition at line 188 of file glogger.h.

warning()

template<typename... Args>

void GLogger::warning ( Args &&... args ) const

inline

Warning messages are always printed and are typically used for recoverable problems, suspicious conditions, or degraded behavior that does not warrant immediate termination.

Template Parameters

Args	Variadic template parameters for any streamable types.

Parameters

args	Message parts to be logged.

This method does not consult verbosity or debug levels.

Definition at line 228 of file glogger.h.

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

• glogger.h