LogHandler Class Reference

Handles custom message handling and sending of stats/logs to Logstash instance. More...

#include <LogHandler.h>

Inherits QObject.

Public Member Functions
bool	parseOptions (const QString &options, const QString &paramName)
	Parse logging options. More...
void	setTargetName (const QString &targetName)
	Set the name of the component that's producing log output. More...
void	setShouldOutputProcessID (bool shouldOutputProcessID)
	Set whether to output the process ID. More...
void	setShouldOutputThreadID (bool shouldOutputThreadID)
	Set whether to output the thread ID. More...
void	setShouldDisplayMilliseconds (bool shouldDisplayMilliseconds)
	Set whether to display timestamps with milliseconds. More...
void	setShouldUseJournald (bool shouldUseJournald)
	Set whether to use Journald, if it's available. More...
bool	isJournaldAvailable () const
	Whether Journald is available on this version/system. More...
QString	printMessage (LogMsgType type, const QMessageLogContext &context, const QString &message)
	Process a log message. More...

Static Public Member Functions
static LogHandler &	getInstance ()
	Returns the one instance of the LogHandler object. More...
static void	verboseMessageHandler (QtMsgType type, const QMessageLogContext &context, const QString &message)
	A qtMessageHandler that can be hooked up to a target that links to Qt. More...
static void	breakOnMessage (const char *str)
	Break when a message that contains the specified string is logged. More...

Detailed Description

Handles custom message handling and sending of stats/logs to Logstash instance.

Member Function Documentation

breakOnMessage()

void LogHandler::breakOnMessage ( const char *  str )

static

Break when a message that contains the specified string is logged.

This is a function intended to be invoked from inside a debugger. It should be of help when it's hard to put a breakpoint on the generating line because it comes from inlined code, or the interesting text is generated at runtime.

Example usage:

LogHandler::breakOnMessage("No instance available for");

Then the debugger should be triggered as soon as a message containing that string is logged. Backtracking through the call stack should lead back to the source.

Note

Support for creating a breakpoint in software is compiler and OS specific. If there's no support for creating a breakpoint on the current compiler/OS, then an abort will be triggered instead.

Parameters

str	Text to match

getInstance()

LogHandler & LogHandler::getInstance ( )

static

Returns the one instance of the LogHandler object.

Returns

LogHandler&

isJournaldAvailable()

bool LogHandler::isJournaldAvailable

(

)

const

Whether Journald is available on this version/system.

Support is available depending on compile options and only on Linux.

Returns

true Journald is available

false Journald is not available

parseOptions()

bool LogHandler::parseOptions	(	const QString &	options,
		const QString &	paramName
	)

Parse logging options.

This parses the logging settings in the environment variable, or from the commandline

Parameters

options	Option list
paramName	Name of the log option, for error reporting.

Returns

true Option list was parsed successfully

false There was an error

printMessage()

QString LogHandler::printMessage	(	LogMsgType	type,
		const QMessageLogContext &	context,
		const QString &	message
	)

Process a log message.

This writes it to a file, logs it to the console, or sends it to journald.

Parameters

type	Log message type
context	Context of the log message (source file, line, function)
message	Log message

Returns

QString The log message's text with added severity and timestamp

setShouldDisplayMilliseconds()

void LogHandler::setShouldDisplayMilliseconds

(

bool

shouldDisplayMilliseconds

)

Set whether to display timestamps with milliseconds.

Parameters

shouldDisplayMilliseconds

setShouldOutputProcessID()

void LogHandler::setShouldOutputProcessID

(

bool

shouldOutputProcessID

)

Set whether to output the process ID.

Note

This has no effect when logging with journald, the PID is always logged

Parameters

shouldOutputProcessID

Whether to output the PID

setShouldOutputThreadID()

void LogHandler::setShouldOutputThreadID

(

bool

shouldOutputThreadID

)

Set whether to output the thread ID.

Parameters

shouldOutputThreadID

setShouldUseJournald()

void LogHandler::setShouldUseJournald

(

bool

shouldUseJournald

)

Set whether to use Journald, if it's available.

Parameters

shouldUseJournald

Whether to use journald

setTargetName()

void LogHandler::setTargetName

(

const QString &

targetName

)

Set the name of the component that's producing log output.

For instance, "assignment-client", "audio-mixer", etc. Called once before logging begins

Parameters

targetName

the desired target name to output in logs

verboseMessageHandler()

void LogHandler::verboseMessageHandler ( QtMsgType  type, const QMessageLogContext &  context, const QString &  message  )

static

A qtMessageHandler that can be hooked up to a target that links to Qt.

Prints various process, message type, and time information

Parameters

type	Log message type
context	Context of the log message (source file, line, function)
message	Log message

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

• LogHandler.h
• LogHandler.cpp