Logging

Detailed Description

The OLA logging system.

Example

\#include <ola/Logging.h>

// Call this once
ola::InitLogging(ola::OLA_LOG_WARN, ola::OLA_LOG_STDERR);

OLA_FATAL << "Null pointer!";
OLA_WARN << "Could not connect to server: " << ip_address;
OLA_INFO << "Reading configs from " << config_dir;
OLA_DEBUG << "Counter was " << counter;

Files
file	Logging.cpp
file	Logging.h
	Header file for OLA Logging.

Namespaces
namespace	ola
	The namespace containing all OLA symbols.

Macros
#define	OLA_LOG(level)
#define	OLA_FATAL   OLA_LOG(ola::OLA_LOG_FATAL)
#define	OLA_WARN   OLA_LOG(ola::OLA_LOG_WARN)
#define	OLA_INFO   OLA_LOG(ola::OLA_LOG_INFO)
#define	OLA_DEBUG   OLA_LOG(ola::OLA_LOG_DEBUG)

Functions
void	ola::SetLogLevel (log_level level)
	Set the logging level.
void	ola::IncrementLogLevel ()
	Increment the log level by one. The log level wraps to OLA_LOG_NONE.
bool	ola::InitLoggingFromFlags ()
	Initialize the OLA logging system from flags.
bool	ola::InitLogging (log_level level, log_output output)
	Initialize the OLA logging system.
void	ola::InitLogging (log_level level, LogDestination *destination)
	Initialize the OLA logging system using the specified LogDestination.
virtual	ola::LogDestination::~LogDestination ()
	Destructor.
virtual void	ola::LogDestination::Write (log_level level, const std::string &log_line)=0
	An abstract function for writing to your log destination.
void	ola::StdErrorLogDestination::Write (log_level level, const std::string &log_line)
	Writes a messages out to stderr.
virtual	ola::SyslogDestination::~SyslogDestination ()
	Destructor.
virtual bool	ola::SyslogDestination::Init ()=0
	Initialize the SyslogDestination.
virtual void	ola::SyslogDestination::Write (log_level level, const std::string &log_line)=0
	Write a line to the system logger.
bool	ola::UnixSyslogDestination::Init ()
	Initialize the UnixSyslogDestination.
void	ola::UnixSyslogDestination::Write (log_level level, const std::string &log_line)
	Write a line to syslog.
log_level	ola::LogLevel ()
	Fetch the current level of logging.

Macro Definition Documentation

#define OLA_DEBUG   OLA_LOG(ola::OLA_LOG_DEBUG)

Provide a stream to log a debug message.

OLA_DEBUG << "Counter was " << counter;

#define OLA_FATAL   OLA_LOG(ola::OLA_LOG_FATAL)

Provide a stream to log a fatal message. e.g.

OLA_FATAL << "Null pointer!";

#define OLA_INFO   OLA_LOG(ola::OLA_LOG_INFO)

Provide a stream to log an infomational message.

OLA_INFO << "Reading configs from " << config_dir;

#define OLA_LOG

(

level

)

Value:

(level <= ola::LogLevel()) && \
                        ola::LogLine(__FILE__, __LINE__, level).stream()

Provide a stream interface to log a message at the specified log level. Rather than calling this directly use one of the OLA_FATAL, OLA_WARN, OLA_INFO or OLA_DEBUG macros.

Parameters

level

the log_level to log at.

#define OLA_WARN   OLA_LOG(ola::OLA_LOG_WARN)

Provide a stream to log a warning message.

OLA_WARN << "Could not connect to server: " << ip_address;

Function Documentation

bool ola::InitLogging	(	log_level	level,
		log_output	output
	)

Initialize the OLA logging system.

Parameters

level	the level to log at
output	the destintion for the logs

Returns

true if logging was initialized sucessfully, false otherwise.

void ola::InitLogging	(	log_level	level,
		LogDestination *	destination
	)

Initialize the OLA logging system using the specified LogDestination.

Parameters

level	the level to log at
destination	the LogDestination to use.

Returns

true if logging was initialized sucessfully, false otherwise.

bool ola::InitLoggingFromFlags

(

)

Initialize the OLA logging system from flags.

Precondition

ParseFlags() must have been called before calling this.

Returns

true if logging was initialized sucessfully, false otherwise.

log_level ola::LogLevel ( )

inline

Fetch the current level of logging.

Returns

the current log_level.

void ola::SetLogLevel

(

log_level

level

)

Set the logging level.

Parameters

level

the new log_level to use.

virtual void ola::LogDestination::Write ( log_level  level, const std::string &  log_line  )

pure virtual

An abstract function for writing to your log destination.

Note

You must over load this if you want to create a new log destination

Implemented in ola::UnixSyslogDestination, ola::SyslogDestination, and ola::StdErrorLogDestination.

virtual void ola::SyslogDestination::Write ( log_level  level, const std::string &  log_line  )

pure virtual

Write a line to the system logger.

Note

This is syslog on *nix or the event log on windows.

Implements ola::LogDestination.

Implemented in ola::UnixSyslogDestination.