Tasks scheduler. More...

#include <Scheduler.h>

Inheritance diagram for Scheduler:

Public Types
typedef long	TaskHandle

Public Types inherited from IScheduler
typedef long	TaskHandle
	Task handle is task identification. More...

typedef std::function< void(const std::string &)>	TaskHandlerFunc
	Task to be processed handler functional type. More...

Public Member Functions
	Scheduler ()

virtual	~Scheduler ()

void	start () override
	Start IScheduler instance. More...

void	stop () override
	Stop IScheduler instance. More...

void	registerMessageHandler (const std::string &clientId, TaskHandlerFunc fun) override
	Register task handler. More...

void	unregisterMessageHandler (const std::string &clientId) override
	Unregister task handler. More...

std::vector< std::string >	getMyTasks (const std::string &clientId) const override
	Get scheduled tasks for a client. More...

std::string	getMyTask (const std::string &clientId, const TaskHandle &hndl) const override
	Get a particular tasks for a client. More...

TaskHandle	scheduleTaskAt (const std::string &clientId, const std::string &task, const std::chrono::system_clock::time_point &tp) override
	Schedule task at time point. More...

TaskHandle	scheduleTaskPeriodic (const std::string &clientId, const std::string &task, const std::chrono::seconds &sec, const std::chrono::system_clock::time_point &tp) override
	Schedule periodic task. More...

void	removeAllMyTasks (const std::string &clientId) override
	Remove all task for client. More...

void	removeTask (const std::string &clientId, TaskHandle hndl) override
	Remove task for client. More...

void	removeTasks (const std::string &clientId, std::vector< TaskHandle > hndls) override
	Remove tasks for client. More...

void	updateConfiguration (const rapidjson::Value &cfg)
	Update configuration. More...

Public Member Functions inherited from IScheduler
virtual	~IScheduler ()

Additional Inherited Members
Static Public Attributes inherited from IScheduler
static const TaskHandle	TASK_HANDLE_INVALID = 0
	Invalid task handle. More...

Detailed Description

Tasks scheduler.

Scheduled tasks are set according a configuration file or during runtime via IScheduler interface. The tasks are scheduled periodically or according a time pattern as defined by Cron syntax. The tasks are stored as std::string and delivered to clients via registered callbacks. It is up to the client to parse content of delivered std::string and handle it approproiatelly. Handling must not block as it is done in the scheduler tasks queue and would block handling of other fired tasks. The client shall create its own handling thread in case of blocking processing.

Runtime scheduling is possible via methods scheduleTaskAt() for task firing at exact time point in future or scheduleTaskPeriodic() for periodic firing with period in soconds.

Scheduling via configuration file allows scheduling according time pattern similar to unix Cron. See for details e.g: https://en.wikipedia.org/wiki/Cron link. Time pattern consist of seven tokens. Unlike Cron it has the token for seconds: "sec min hour day mon year wday". The tokens are accepted in these Cron forms, e.g:

Token	meaning
*	every
3	3rd
1,2,3	1st, 2nd, 3rd
5/*	every divisible by 5

It is possible to use Cron nicknames for time pattern.

"@reboot": Run once after reboot.
"@yearly": Run once a year, ie. "0 0 0 0 1 1 *".
"@annually": Run once a year, ie. "0 0 0 0 1 1 *".
"@monthly": Run once a month, ie. "0 0 0 0 1 * *".
"@weekly": Run once a week, ie. "0 0 0 * * * 0".
"@daily": Run once a day, ie. "0 0 0 * * * *".
"@hourly": Run once an hour, ie. "0 0 * * * * *".
"@minutely": Run once a minute, ie. "0 * * * * * *".

Configuration file is accepted in this JSON format:

{
 "TasksJson" : [                        #tasks array
  {
    "time": "*/5 6 * * * * *",          #time pattern
    "service" : "BaseServiceForMQTT1",  #id of callback registrator
    "message" : {                       #task (passed as std::string)
      "ctype": "dpa",
      "type" : "raw",
      "msgid" : "1",
      "timeout" : 1000,
      "request" : "00.00.06.03.ff.ff",
      "request_ts" : "",
      "confirmation" : ".",
      "confirmation_ts" : "",
      "response" : ".",
      "response_ts" : ""
  }
 ]
}

Member Typedef Documentation

◆ TaskHandle

typedef long Scheduler::TaskHandle

Constructor & Destructor Documentation

◆ Scheduler()

Scheduler::Scheduler ( )

◆ ~Scheduler()

Scheduler::~Scheduler ( )

virtual

Member Function Documentation

◆ getMyTask()

std::string Scheduler::getMyTask	(	const std::string &	clientId,
		const TaskHandle &	hndl
	)		const

overridevirtual

Get a particular tasks for a client.

Parameters

[in]	clientId	client identification
[in]	hndl	task handle identification

Returns: scheduled tasks

Returns a particular task planned for a client or an empty task if doesn't exists

Implements IScheduler.

◆ getMyTasks()

std::vector< std::string > Scheduler::getMyTasks ( const std::string & clientId ) const

overridevirtual

Get scheduled tasks for a client.

Parameters

[in] clientId client identification

Returns: scheduled tasks

Returns all pending scheduled tasks for the client

Implements IScheduler.

◆ registerMessageHandler()

void Scheduler::registerMessageHandler	(	const std::string &	clientId,
		TaskHandlerFunc	fun
	)

overridevirtual

Register task handler.

Parameters

[in]	clientId	client identification registering handler function
[in]	fun	handler function

Whenever the scheduler evaluate a task to be handled it is passed to the handler function. The only tasks planned for particular clientId are delivered. Repeated registration with the same client identification replaces previously registered handler

Implements IScheduler.

◆ removeAllMyTasks()

void Scheduler::removeAllMyTasks ( const std::string & clientId )

overridevirtual

Remove all task for client.

Parameters

[in] clientId client identification

Scheduler removes all tasks for the client

Implements IScheduler.

◆ removeTask()

void Scheduler::removeTask	(	const std::string &	clientId,
		TaskHandle	hndl
	)

overridevirtual

Remove task for client.

Parameters

[in]	clientId	client identification
[in]	hndl	task handle identification

Scheduler removes a particular tasks for the client

Implements IScheduler.

◆ removeTasks()

void Scheduler::removeTasks	(	const std::string &	clientId,
		std::vector< TaskHandle >	hndls
	)

overridevirtual

Remove tasks for client.

Parameters

[in]	clientId	client identification
[in]	hndls	task handles identification

Scheduler removes a group of tasks passed in hndls for the client

Implements IScheduler.

◆ scheduleTaskAt()

Scheduler::TaskHandle Scheduler::scheduleTaskAt	(	const std::string &	clientId,
		const std::string &	task,
		const std::chrono::system_clock::time_point &	tp
	)

overridevirtual

Schedule task at time point.

Parameters

[in]	clientId	client identification
[in]	task	planned task
[in]	tp	time point

Returns: scheduled task handle

Schedules task at exact time point. When the time point is reached the task is passed to its handler and released Use it for one shot tasks

Implements IScheduler.

◆ scheduleTaskPeriodic()

Scheduler::TaskHandle Scheduler::scheduleTaskPeriodic	(	const std::string &	clientId,
		const std::string &	task,
		const std::chrono::seconds &	sec,
		const std::chrono::system_clock::time_point &	tp
	)

overridevirtual

Schedule periodic task.

Parameters

[in]	clientId	client identification
[in]	task	planned task
[in]	sec	period in seconds
[in]	tp	time point of delayed start

Returns: scheduled task handle

Schedules periodic task. It is started immediatelly by default, the first shot after one period. If the start shall be delayed use appropriate time point of start

Implements IScheduler.

◆ start()

void Scheduler::start ( )

overridevirtual

Start IScheduler instance.

Scheduler implementation starts to process scheduled tasks

Implements IScheduler.

◆ stop()

void Scheduler::stop ( )

overridevirtual

Stop IScheduler instance.

Scheduler implementation stops processing of scheduled tasks

Implements IScheduler.

◆ unregisterMessageHandler()

void Scheduler::unregisterMessageHandler ( const std::string & clientId )

overridevirtual

Unregister task handler.

Parameters

[in] clientId client identification

If the handler is not required anymore, it is possible to unregister via this method.

Implements IScheduler.

◆ updateConfiguration()

void Scheduler::updateConfiguration ( const rapidjson::Value & cfg )

Update configuration.

Parameters

[in] cfg configuration data

Configuration data are taken from passed cfg and the instance is configured accordingly

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

daemon/Scheduler/Scheduler.h
daemon/Scheduler/Scheduler.cpp

Public Types

Public Member Functions

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ TaskHandle

Constructor & Destructor Documentation

◆ Scheduler()

◆ ~Scheduler()

Member Function Documentation

◆ getMyTask()

◆ getMyTasks()

◆ registerMessageHandler()

◆ removeAllMyTasks()

◆ removeTask()

◆ removeTasks()

◆ scheduleTaskAt()

◆ scheduleTaskPeriodic()

◆ start()

◆ stop()

◆ unregisterMessageHandler()

◆ updateConfiguration()