lsst::log::Log Class Reference

This static class includes a variety of methods for interacting with the the logging module. More...

#include <Log.h>

Public Member Functions
	Log ()
bool	isDebugEnabled () const
	Check whether the logger is enabled for the DEBUG Level. More...
bool	isErrorEnabled () const
	Check whether the logger is enabled for the ERROR Level. More...
bool	isFatalEnabled () const
	Check whether the logger is enabled for the FATAL Level. More...
bool	isInfoEnabled () const
	Check whether the logger is enabled for the INFO Level. More...
bool	isTraceEnabled () const
	Check whether the logger is enabled for the TRACE Level. More...
bool	isWarnEnabled () const
	Check whether the logger is enabled for the WARN Level. More...
std::string	getName () const
	Get the logger name associated with the Log object. More...
void	setLevel (int level)
	Set the logging threshold to LEVEL. More...
int	getLevel () const
	Retrieve the logging threshold. More...
int	getEffectiveLevel () const
	Retrieve the effective logging threshold. More...
bool	isEnabledFor (int level) const
	Return whether the logging threshold of the logger is less than or equal to LEVEL. More...
Log	getChild (std::string const &suffix) const
	Return a logger which is a descendant to this logger. More...
void	log (log4cxx::LevelPtr level, log4cxx::spi::LocationInfo const &location, char const *fmt,...)
	Method used by LOG_INFO and similar macros to process a log message with variable arguments along with associated metadata. More...
void	logMsg (log4cxx::LevelPtr level, log4cxx::spi::LocationInfo const &location, std::string const &msg)
	Method used by LOGS_INFO and similar macros to process a log message. More...

Static Public Member Functions
static Log	getDefaultLogger ()
	Return default logger instance, same as default constructor. More...
static void	configure ()
	Explicitly configures log4cxx and initializes logging system. More...
static void	configure (std::string const &filename)
	Configures log4cxx from specified file. More...
static void	configure_prop (std::string const &properties)
	Configures log4cxx using a string containing the list of properties, equivalent to configuring from a file containing the same content but without creating temporary files. More...
static Log	getLogger (Log const &logger)
static Log	getLogger (std::string const &loggername)
	Returns logger object for a given name. More...
static std::string	MDC (std::string const &key, std::string const &value)
	Places a KEY/VALUE pair in the Mapped Diagnostic Context (MDC) for the current thread. More...
static void	MDCRemove (std::string const &key)
	Remove the value associated with KEY within the MDC. More...
static int	MDCRegisterInit (std::function< void()> function)

Detailed Description

This static class includes a variety of methods for interacting with the the logging module.

These methods are not meant for direct use. Rather, they are used by the LOG* macros and the SWIG interface declared in logInterface.h.

Definition at line 724 of file Log.h.

Constructor & Destructor Documentation

Log()

lsst::log::Log::Log ( )

inline

Definition at line 730 of file Log.h.

: _logger(_defaultLogger()) { }

Member Function Documentation

configure() [1/2]

void lsst::log::Log::configure ( )

static

Explicitly configures log4cxx and initializes logging system.

Configuration can be specified via environment variable LSST_LOG_CONFIG, if it is set and specifies existing file name then this file name is used for configuration. Otherwise pre-defined configuration is used, which is hardwired to add to the root logger a ConsoleAppender. In this case, the output will be formatted using a PatternLayout set to the pattern "%c %p: %m%n".

Definition at line 177 of file Log.cc.

                    {
    std::lock_guard<std::mutex> lock(::configMutex);
 
    // Make sure other threads know that default configuration is not needed
    ::initialized = true;
 
    // This removes all defined appenders, resets level to DEBUG,
    // existing loggers are not deleted, only reset.
    log4cxx::BasicConfigurator::resetConfiguration();
 
    // Do default configuration (only if not configured already?)
    ::defaultConfig();
}

configure() [2/2]

void lsst::log::Log::configure ( std::string const &  filename )

static

Configures log4cxx from specified file.

If file name ends with ".xml", it is passed to log4cxx::xml::DOMConfigurator::configure(). Otherwise, it assumed to be a log4j Java properties file and is passed to log4cxx::PropertyConfigurator::configure(). See http://logging.apache.org/log4cxx/usage.html for additional details.

Parameters

filename

Path to configuration file.

Definition at line 201 of file Log.cc.

                                             {
    std::lock_guard<std::mutex> lock(::configMutex);
 
    // Make sure other threads know that default configuration is not needed
    ::initialized = true;
 
    // This removes all defined appenders, resets level to DEBUG,
    // existing loggers are not deleted, only reset.
    log4cxx::BasicConfigurator::resetConfiguration();
 
    ::configFromFile(filename);
}

configure_prop()

void lsst::log::Log::configure_prop ( std::string const &  properties )

static

Configures log4cxx using a string containing the list of properties, equivalent to configuring from a file containing the same content but without creating temporary files.

Parameters

properties

Configuration properties.

Definition at line 220 of file Log.cc.

                                                    {
    std::lock_guard<std::mutex> lock(::configMutex);
 
    // Make sure other threads know that default configuration is not needed
    ::initialized = true;
 
    // This removes all defined appenders, resets level to DEBUG,
    // existing loggers are not deleted, only reset.
    log4cxx::BasicConfigurator::resetConfiguration();
 
    std::vector<unsigned char> data(properties.begin(), properties.end());
    log4cxx::helpers::InputStreamPtr inStream(new log4cxx::helpers::ByteArrayInputStream(data));
    log4cxx::helpers::Properties prop;
    prop.load(inStream);
    log4cxx::PropertyConfigurator::configure(prop);
}

getChild()

Log lsst::log::Log::getChild

(

std::string const &

suffix

)

const

Return a logger which is a descendant to this logger.

If for example name of this logger is "main.task" and suffix is "subtask1.algorithm" then this method will return logger with the name "main.task.subtask1.algorithm". If this logger is root logger then suffix name is used for returned logger name. If suffix is empty then this instance is returned.

Parameters

suffix

Suffix for tha name of returned logger, can include dot (but not at leading position) and can be empty.

Returns

Log instance.

Definition at line 366 of file Log.cc.

                                               {
    // strip leading dots and spaces from suffix
    auto pos = suffix.find_first_not_of(" .");
    if (pos == std::string::npos) {
        // empty, just return myself
        return *this;
    }
    std::string name = getName();
    if (name.empty()) {
        name = suffix.substr(pos);
    } else {
        name += '.';
        name += suffix.substr(pos);
    }
    return getLogger(name);
}

getDefaultLogger()

static Log lsst::log::Log::getDefaultLogger ( )

inlinestatic

Return default logger instance, same as default constructor.

Definition at line 766 of file Log.h.

{ return Log(); }

getEffectiveLevel()

int lsst::log::Log::getEffectiveLevel

(

)

const

Retrieve the effective logging threshold.

Returns

int Indicating the effective logging threshold.

Definition at line 330 of file Log.cc.

                                 {
    log4cxx::LevelPtr level = _logger->getEffectiveLevel();
    int levelno = -1;
    if (level != NULL) {
        levelno = level->toInt();
    }
    return levelno;
}

getLevel()

int lsst::log::Log::getLevel

(

)

const

Retrieve the logging threshold.

Returns

int Indicating the logging threshold.

Definition at line 318 of file Log.cc.

                        {
    log4cxx::LevelPtr level = _logger->getLevel();
    int levelno = -1;
    if (level != NULL) {
        levelno = level->toInt();
    }
    return levelno;
}

getLogger() [1/2]

static Log lsst::log::Log::getLogger ( Log const &  logger )

inlinestatic

Definition at line 772 of file Log.h.

{ return logger; }

getLogger() [2/2]

Log lsst::log::Log::getLogger ( std::string const &  loggername )

static

Returns logger object for a given name.

If name is empty then current logger is returned and not a root logger.

Parameters

loggername

Name of logger to return.

Returns

Log instance corresponding to logger name.

Definition at line 256 of file Log.cc.

                                              {
    if (loggername.empty()){
        return getDefaultLogger();
    } else {
        return Log(log4cxx::Logger::getLogger(loggername));
    }
}

getName()

std::string lsst::log::Log::getName

(

)

const

Get the logger name associated with the Log object.

Returns

String containing the logger name.

Definition at line 240 of file Log.cc.

                             {
    std::string name = _logger->getName();
    if (name == "root") {
        name.clear();
    }
    return name;
}

isDebugEnabled()

bool lsst::log::Log::isDebugEnabled ( ) const

inline

Check whether the logger is enabled for the DEBUG Level.

Definition at line 735 of file Log.h.

{ return _logger->isDebugEnabled(); }

isEnabledFor()

bool lsst::log::Log::isEnabledFor

(

int

level

)

const

Return whether the logging threshold of the logger is less than or equal to LEVEL.

Returns

Bool indicating whether or not logger is enabled.

Parameters

level

Logging threshold to check.

Definition at line 345 of file Log.cc.

                                      {
    if (_logger->isEnabledFor(log4cxx::Level::toLevel(level))) {
        return true;
    } else {
        return false;
    }
}

isErrorEnabled()

bool lsst::log::Log::isErrorEnabled ( ) const

inline

Check whether the logger is enabled for the ERROR Level.

Definition at line 739 of file Log.h.

{ return _logger->isErrorEnabled(); }

isFatalEnabled()

bool lsst::log::Log::isFatalEnabled ( ) const

inline

Check whether the logger is enabled for the FATAL Level.

Definition at line 743 of file Log.h.

{ return _logger->isFatalEnabled(); }

isInfoEnabled()

bool lsst::log::Log::isInfoEnabled ( ) const

inline

Check whether the logger is enabled for the INFO Level.

Definition at line 747 of file Log.h.

{ return _logger->isInfoEnabled(); }

isTraceEnabled()

bool lsst::log::Log::isTraceEnabled ( ) const

inline

Check whether the logger is enabled for the TRACE Level.

Definition at line 751 of file Log.h.

{ return _logger->isTraceEnabled(); }

isWarnEnabled()

bool lsst::log::Log::isWarnEnabled ( ) const

inline

Check whether the logger is enabled for the WARN Level.

Definition at line 755 of file Log.h.

{ return _logger->isWarnEnabled(); }

log()

void lsst::log::Log::log	(	log4cxx::LevelPtr	level,
		log4cxx::spi::LocationInfo const &	location,
		char const *	fmt,
			...
	)

Method used by LOG_INFO and similar macros to process a log message with variable arguments along with associated metadata.

Parameters

level	message level
location	message origin location
fmt	message format string
...	message arguments

Definition at line 386 of file Log.cc.

               {
    va_list args;
    va_start(args, fmt);
    char msg[MAX_LOG_MSG_LEN];
    vsnprintf(msg, MAX_LOG_MSG_LEN, fmt, args);
    logMsg(level, location, msg);
}

logMsg()

void lsst::log::Log::logMsg	(	log4cxx::LevelPtr	level,
		log4cxx::spi::LocationInfo const &	location,
		std::string const &	msg
	)

Method used by LOGS_INFO and similar macros to process a log message.

Parameters

level	message level
location	message origin location
msg	message string

Definition at line 400 of file Log.cc.

                   {
 
    // do one-time per-thread initialization, this was implemented
    // with thread_local initially but clang on OS X did not support it
    void *ptr = pthread_getspecific(::pthreadKey.key);
    if (ptr == nullptr) {
 
        // use pointer value as a flag, don't care where it points to
        ptr = static_cast<void*>(&::pthreadKey);
        pthread_setspecific(::pthreadKey.key, ptr);
 
        std::lock_guard<std::mutex> lock(mdcInitMutex);
                // call all functions in the MDC init list
        for (auto& fun: mdcInitFunctions) {
            fun();
        }
    }
 
    // forward everything to logger
    _logger->forcedLog(level, msg, location);
}

MDC()

std::string lsst::log::Log::MDC ( std::string const &  key, std::string const &  value  )

static

Places a KEY/VALUE pair in the Mapped Diagnostic Context (MDC) for the current thread.

The VALUE may then be included in log messages by using the following the X conversion character within a pattern layout as X{KEY}. Note that unlike log4cxx::MDC::put() this method overwrites any previously existing mapping.

Parameters

key	Unique key.
value	String value.

Returns

Previous value for the key in the MDC.

Definition at line 274 of file Log.cc.

                                                               {
    // put() does not remove existing mapping, to make it less confusing
    // for clients which expect that MDC() always overwrites existing mapping
    // we explicitly remove it first if it exists.
    std::string const oldValue = log4cxx::MDC::get(key);
    log4cxx::MDC::remove(key);
    log4cxx::MDC::put(key, value);
    return oldValue;
}

MDCRegisterInit()

int lsst::log::Log::MDCRegisterInit ( std::function< void()>  function )

static

Definition at line 292 of file Log.cc.

                                                     {
 
    std::lock_guard<std::mutex> lock(mdcInitMutex);
 
    // logMsg may have been called already in this thread, to make sure that
    // this function is executed in this thread call it explicitly
    function();
 
    // store function for later use
    ::mdcInitFunctions.push_back(std::move(function));
 
    // return arbitrary number
    return 1;
}

MDCRemove()

void lsst::log::Log::MDCRemove ( std::string const &  key )

static

Remove the value associated with KEY within the MDC.

Parameters

key	Key identifying value to remove.

Definition at line 288 of file Log.cc.

                                        {
    log4cxx::MDC::remove(key);
}

setLevel()

void lsst::log::Log::setLevel

(

int

level

)

Set the logging threshold to LEVEL.

Parameters

level

New logging threshold.

Definition at line 311 of file Log.cc.

                            {
    _logger->setLevel(log4cxx::Level::toLevel(level));
}

---

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

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/log/22.0.1-8-ge5750ce+85460ae5f3/include/lsst/log/Log.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/log/22.0.1-8-ge5750ce+85460ae5f3/src/Log.cc