The interface that needs to be implemented to provide the backend for the service engine. More...

#include <servicebackend.h>

Inheritance diagram for QtService::ServiceBackend:

Public Types
enum	ServiceCommand { StartCommand, StopCommand, ReloadCommand, PauseCommand, ResumeCommand }
	The standard service commands that the library can handle. More...

Public Member Functions
	ServiceBackend (Service *service)
	Constructor with the service instance the backend was created for.

virtual int	runService (int &argc, char **argv, int flags)=0
	Is called as the services main function by the library from Service::exec. More...

virtual void	quitService ()=0
	Is called by Service::quit to stop the service programatically. More...

virtual void	reloadService ()=0
	Is called by Service::reload to reload the service programatically. More...

virtual QList< int >	getActivatedSockets (const QByteArray &name)
	Is called by Service::getSockets and Service::getSocket to get the activated sockets. More...

Public Member Functions inherited from QObject
virtual const QMetaObject *	metaObject () const const

virtual void *	qt_metacast (const char *)

virtual int	qt_metacall (QMetaObject::Call, int, void **)

	QObject (QObject *parent)

virtual bool	event (QEvent *e)

virtual bool	eventFilter (QObject watched, QEvent event)

QString	objectName () const const

void	setObjectName (const QString &name)

bool	isWidgetType () const const

bool	isWindowType () const const

bool	signalsBlocked () const const

bool	blockSignals (bool block)

QThread *	thread () const const

void	moveToThread (QThread *targetThread)

int	startTimer (int interval, Qt::TimerType timerType)

int	startTimer (std::chrono::milliseconds time, Qt::TimerType timerType)

void	killTimer (int id)

T	findChild (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QString &name, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QRegExp &regExp, Qt::FindChildOptions options) const const

QList< T >	findChildren (const QRegularExpression &re, Qt::FindChildOptions options) const const

const QObjectList &	children () const const

void	setParent (QObject *parent)

void	installEventFilter (QObject *filterObj)

void	removeEventFilter (QObject *obj)

QMetaObject::Connection	connect (const QObject sender, const char signal, const char *method, Qt::ConnectionType type) const const

bool	disconnect (const char signal, const QObject receiver, const char *method) const const

bool	disconnect (const QObject receiver, const char method) const const

void	dumpObjectTree ()

void	dumpObjectInfo ()

void	dumpObjectTree () const const

void	dumpObjectInfo () const const

bool	setProperty (const char *name, const QVariant &value)

QVariant	property (const char *name) const const

QList< QByteArray >	dynamicPropertyNames () const const

void	destroyed (QObject *obj)

void	objectNameChanged (const QString &objectName)

QObject *	parent () const const

bool	inherits (const char *className) const const

void	deleteLater ()

Protected Slots
virtual void	signalTriggered (int signal)
	Is called by the library if a unix signal or windows console signal was triggered. More...

void	processServiceCommand (QtService::ServiceBackend::ServiceCommand code)
	Calls the Service standard methods for the given command code. More...

QVariant	processServiceCallbackImpl (const QByteArray &kind, const QVariantList &args={})
	Calls a special command as service callback synchronously. More...

Protected Member Functions
QtService::Service *	service () const
	The Service instance this backend was created with.

template<typename TRet , typename... TArgs>
TRet	processServiceCallback (const QByteArray &kind, TArgs... args)
	Calls a special command as service callback synchronously. More...

template<typename... TArgs>
void	processServiceCallback (const QByteArray &kind, TArgs... args)
	Calls a special command as service callback synchronously. More...

bool	registerForSignal (int signal)
	Register for a unix/windows signal your backend wants to handle. More...

bool	unregisterFromSignal (int signal)
	Unregister from a unix/windows signal your backend doesn't want to handle anymore. More...

bool	preStartService ()
	Calls the Service::preStart method synchronously. More...

Protected Member Functions inherited from QObject
QObject *	sender () const const

int	senderSignalIndex () const const

int	receivers (const char *signal) const const

bool	isSignalConnected (const QMetaMethod &signal) const const

virtual void	timerEvent (QTimerEvent *event)

virtual void	childEvent (QChildEvent *event)

virtual void	customEvent (QEvent *event)

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

Additional Inherited Members
Static Public Member Functions inherited from QObject
QString	tr (const char sourceText, const char disambiguation, int n)

QString	trUtf8 (const char sourceText, const char disambiguation, int n)

QMetaObject::Connection	connect (const QObject sender, const char signal, const QObject receiver, const char method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method, Qt::ConnectionType type)

QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, Functor functor)

QMetaObject::Connection	connect (const QObject sender, PointerToMemberFunction signal, const QObject context, Functor functor, Qt::ConnectionType type)

bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char method)

bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method)

bool	disconnect (const QMetaObject::Connection &connection)

bool	disconnect (const QObject sender, PointerToMemberFunction signal, const QObject receiver, PointerToMemberFunction method)

Properties inherited from QObject
	objectName

Detailed Description

The interface that needs to be implemented to provide the backend for the service engine.

This class is only needed when implementing your own service backend. It's what the Service uses internally to properly run and interact with the service systems

See also: Service, ServicePlugin

Definition at line 15 of file servicebackend.h.

Member Enumeration Documentation

◆ ServiceCommand

enum QtService::ServiceBackend::ServiceCommand

The standard service commands that the library can handle.

Enumerator
StartCommand	Service was started. Will lead to Service::onStart beeing called.
StopCommand	Service should stop. Will lead to Service::onStop beeing called.
ReloadCommand	Service should reload. Will lead to Service::onReload beeing called.
PauseCommand	Service should pause. Will lead to Service::onPause beeing called.
ResumeCommand	Service was resumed. Will lead to Service::onResume beeing called.

Definition at line 21 of file servicebackend.h.

Member Function Documentation

◆ getActivatedSockets()

QtService::ServiceBackend::getActivatedSockets ( const QByteArray & name )

virtual

Is called by Service::getSockets and Service::getSocket to get the activated sockets.

Parameters

name	The name of the socket(s) to be retrieved, or a null name for the default socket.

Returns: A list with all sockets found for that name, or an empty list if non were found

If your service backends supports socket activation, implement this method to make the available. It is either called with a name passed to Service::getSockets, or with a null bytearray if the default socket (Service::getSocket) was requested. Sockets returned from this method should be ready to use, aka in the listening state (this is typically the case for bound sockets)

See also: Service::getSockets, Service::getSocket, QByteArray::isNull

◆ preStartService()

QtService::ServiceBackend::preStartService ( )

protected

Calls the Service::preStart method synchronously.

Returns: true if startup can be continued, false to cancle early

You should call this method right after creating the QCoreApplication object and after setting up logging. It's a wrapper that calls Service::preStart and returns it's value. If false is returned the service cannot start properly and you should exit as soon as possible.

Note: If you need to complete the startup and enter the running state, do so. But if false was returned instead of calling the start command simply quit the service without ever starting. If you implement it that way, make shure neither the start nor the stop command are ever triggered

See also: Service::preStart

◆ processServiceCallback() [1/2]

template<typename TRet , typename... TArgs>

TRet QtService::ServiceBackend::processServiceCallback	(	const QByteArray &	kind,
		TArgs...	args
	)

protected

Calls a special command as service callback synchronously.

Template Parameters

TRet	The return type
TArgs	Generic arguments types

Parameters

kind	The kind of callback to be called
args	The arguments of the callback

Returns: The return of the callback

Wrapper that calls Service::onCallback and returns it's value. This method call is, unlike other commands, synchronous.

See also: ServiceBackend::processServiceCallback, Service::onCallback

Definition at line 91 of file servicebackend.h.

◆ processServiceCallback() [2/2]

template<typename... TArgs>

void QtService::ServiceBackend::processServiceCallback	(	const QByteArray &	kind,
		TArgs...	args
	)

protected

Calls a special command as service callback synchronously.

Template Parameters

TArgs Generic arguments types

Parameters

kind	The kind of callback to be called
args	The arguments of the callback

Returns: The return of the callback

Wrapper that calls Service::onCallback and returns it's value. This method call is, unlike other commands, synchronous.

See also: ServiceBackend::processServiceCallback, Service::onCallback

Definition at line 97 of file servicebackend.h.

◆ processServiceCallbackImpl

QtService::ServiceBackend::processServiceCallbackImpl	(	const QByteArray &	kind,
		const QVariantList &	args = `{}`
	)

protectedslot

Calls a special command as service callback synchronously.

Parameters

kind	The kind of callback to be called
args	The arguments of the callback

Returns: The return of the callback

Wrapper that calls Service::onCallback and returns it's value. This method call is, unlike other commands, synchronous.

See also: ServiceBackend::processServiceCallback, Service::onCallback

◆ processServiceCommand

QtService::ServiceBackend::processServiceCommand ( QtService::ServiceBackend::ServiceCommand code )

protectedslot

Calls the Service standard methods for the given command code.

Parameters

code	The command code to be executed

This method calls the correspondig onCommand method of the Service instance. This method takes care of both sync and async calls. For usage, you should always assume asynchronous runs. In other words, do not complete the operation after this method returns. Instead connect to the coresponding done signal and continue from there.

Note: Connections to those signals should be done before calling this method, as they might be emitted before the method returns! Use queued connections if that would conflict with your implementation

The methods called and signals to connect to for each command are:

Command	Method	Signal
ServiceBackend::StartCommand	Service::onStart	Service::started
ServiceBackend::StopCommand	Service::onStop	Service::stopped
ServiceBackend::ReloadCommand	Service::onReload	Service::reloaded
ServiceBackend::PauseCommand	Service::onPause	Service::paused
ServiceBackend::ResumeCommand	Service::onResume	Service::resumed

See also: ServiceBackend::ServiceCommand, ServiceBackend::service

◆ quitService()

QtService::ServiceBackend::quitService ( )

pure virtual

Is called by Service::quit to stop the service programatically.

Your implementation should perform a graceful service exit. This means a call to this method should behave the same as stopping the service from the service manager.

See also: Service::quit, Service::onStop

◆ registerForSignal()

QtService::ServiceBackend::registerForSignal ( int signal )

protected

Register for a unix/windows signal your backend wants to handle.

Parameters

signal The signal to register for

Returns: true if the signal was (or already has been) registered

You need to call this method to register a signal you want to handle. After registering it, it will be delivered via ServiceBackend::signalTriggered as soon as it is triggered.

See also: ServiceBackend::signalTriggered, ServiceBackend::unregisterFromSignal

◆ reloadService()

QtService::ServiceBackend::reloadService ( )

pure virtual

Is called by Service::reload to reload the service programatically.

Your implementation should perform a service reload. This means a call to this method should behave the same as reloading the service from the service manager. If reloading is not supported by your backend, simply call processServiceCommand(ReloadCommand); to properly handle the reload with doing anything service-manager related.

See also: Service::reload, Service::onReload

◆ runService()

QtService::ServiceBackend::runService	(	int &	argc,
		char **	argv,
		int	flags
	)

pure virtual

Is called as the services main function by the library from Service::exec.

Parameters

argc	The argc from Service, i.e. from the main
argv	The argv from Service, i.e. from the main
flags	The flags from Service, i.e. from the main

Returns: The return value from QCoreApplication::exec

This method should perform all the required startup stuff for the service, prepare logging etc. What must do is to create a QCoreApplication (or another application) and eventually run QCoreApplication::exec - as this method should also block until execution finished. You should return the exit code form the main if possible.

Returning from this method early should typically be done only in case of an error and an error exit code returned.

Internally, you must use ServiceBackend::processServiceCommand (and ServiceBackend::processServiceCallback) at the appropriate points in your implementation to call the corresponding service methods.

See also: Service::exec, Service::Service

◆ signalTriggered

QtService::ServiceBackend::signalTriggered ( int signal )

protectedvirtualslot

Is called by the library if a unix signal or windows console signal was triggered.

Parameters

signal The signal that was triggered

If you need to handle signals, this is the easiest way. Please note that this method is called asynchronously. So if you need signal handlers that are synchronous, you must implement them yourself. The signal values are the standard defined values of signals for all platforms, i.e. the SIGINT signal on unix is the same as that define from the signal.h header.

In order to be able to catch signals with this method they must be registered first. Use ServiceBackend::registerForSignal to do so.

See also: ServiceBackend::registerForSignal, ServiceBackend::unregisterFromSignal

◆ unregisterFromSignal()

QtService::ServiceBackend::unregisterFromSignal ( int signal )

protected

Unregister from a unix/windows signal your backend doesn't want to handle anymore.

Parameters

signal The signal to unregister from

Returns: true if the signal was (or already has been) unregistered

After unregistering, the "default signal handler" will be used again to handle such a signal. In other words the state before the registration is recovered.

See also: ServiceBackend::signalTriggered, ServiceBackend::registerForSignal

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

servicebackend.h
servicebackend.dox

Public Types

Public Member Functions

Protected Slots

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ ServiceCommand

Member Function Documentation

◆ getActivatedSockets()

◆ preStartService()

◆ processServiceCallback() [1/2]

◆ processServiceCallback() [2/2]

◆ processServiceCallbackImpl

◆ processServiceCommand

◆ quitService()

◆ registerForSignal()

◆ reloadService()

◆ runService()

◆ signalTriggered

◆ unregisterFromSignal()