A lazy subscriber that subscribes only when a condition is met. More...

#include <lazy_subscriber.hpp>

Inheritance diagram for cras::ConditionalSubscriber:

[legend]

Public Types
typedef ::std::function< void(::ros::Subscriber &sub)>	ConnectFn
	Type of the function that connects the subscriber. More...

typedef ::std::function< void(::ros::Subscriber &sub)>	DisconnectFn
	Type of the function that disconnects the subscriber. More...

Public Member Functions
	ConditionalSubscriber (ConnectFn connectFn, const ::cras::LogHelperPtr &logHelper=::std::make_shared<::cras::NodeLogHelper >())
	Create the conditional subscriber. More...

	ConditionalSubscriber (ConnectFn connectFn, DisconnectFn disconnectFn, const ::cras::LogHelperPtr &logHelper=::std::make_shared<::cras::NodeLogHelper >())
	Create the conditional subscriber. More...

bool	isLazy () const
	Tell whether this subscriber has the lazy behavior enabled. More...

bool	isSubscribed () const
	Whether the subscriber is currently subscribed to its topic or not. More...

void	setLazy (bool lazy)
	Set whether the subscriber behaves in the lazy way. More...

virtual	~ConditionalSubscriber ()
	Destroy this object and unsubscribe the subscriber if it was subscribed. More...

Public Member Functions inherited from cras::HasLogger
::cras::LogHelperConstPtr	getCrasLogger () const

	HasLogger (const ::cras::LogHelperPtr &log)

void	setCrasLogger (const ::cras::LogHelperPtr &log)

Protected Member Functions
void	connectNoLock ()
	Connect the subscriber to its input. More...

void	disconnectNoLock ()
	Disconnect the subscriber from its input. More...

virtual bool	shouldBeSubscribed () const =0
	Tell whether the subscriber should be subscribed or not. More...

void	updateSubscription ()
	The callback called when the condition might have changed. More...

void	updateSubscriptionNoLock ()
	The callback called when the condition might have changed. More...

Protected Attributes
ConnectFn	connectFn
	The function used to establish connection. More...

mutable ::std::mutex	connectMutex
	Mutex protecting `sub` and `subscribed`. More...

DisconnectFn	disconnectFn
	The function used to close connection. More...

bool	lazy {true}
	Whether the lazy behavior is enabled (if false, the subscriber is always subscribed). More...

::ros::Subscriber	sub
	The underlying subscriber (valid only when `subscribed` is true). More...

bool	subscribed {false}
	Whether the subscriber is currently subscribed to its topic or not. More...

Protected Attributes inherited from cras::HasLogger
::cras::LogHelperPtr	log

Detailed Description

A lazy subscriber that subscribes only when a condition is met.

Definition at line 33 of file lazy_subscriber.hpp.

Member Typedef Documentation

◆ ConnectFn

typedef ::std::function<void(::ros::Subscriber& sub)> cras::ConditionalSubscriber::ConnectFn

Type of the function that connects the subscriber.

Parameters

[out] sub Reference to the subscriber object to be created.

Definition at line 38 of file lazy_subscriber.hpp.

◆ DisconnectFn

typedef ::std::function<void(::ros::Subscriber& sub)> cras::ConditionalSubscriber::DisconnectFn

Type of the function that disconnects the subscriber.

Parameters

[in,out] Reference to the subscriber object to be disconnected.

Definition at line 42 of file lazy_subscriber.hpp.

Constructor & Destructor Documentation

◆ ConditionalSubscriber() [1/2]

cras::ConditionalSubscriber::ConditionalSubscriber	(	ConnectFn	connectFn,
		DisconnectFn	disconnectFn,
		const ::cras::LogHelperPtr &	logHelper = `::std::make_shared<::cras::NodeLogHelper >()`
	)

Create the conditional subscriber.

Parameters

[in]	connectFn	The function that connects the subscriber. It should store the subscriber in the passed `sub` object.
[in]	disconnectFn	The function that disconnects the subscriber. The `sub` object passed to the function is the one created previously by `connectFn`. The passed subscriber should be invalidated.
[in]	logHelper	Logging helper.

Note: The base class itself does not regularly check the connect/disconnect condition. Subclasses are responsible for calling updateSubscription() when it is possible that the subscription condition changed.

◆ ConditionalSubscriber() [2/2]

cras::ConditionalSubscriber::ConditionalSubscriber	(	ConnectFn	connectFn,
		const ::cras::LogHelperPtr &	logHelper = `::std::make_shared<::cras::NodeLogHelper >()`
	)

explicit

Create the conditional subscriber.

Parameters

[in]	connectFn	The function that connects the subscriber. It should store the subscriber in the passed `sub` object. Disconnection is done by simply calling `sub.shutdown()`.
[in]	logHelper	Logging helper.

Note: The base class itself does not regularly check the connect/disconnect condition. Subclasses are responsible for calling updateSubscription() when it is possible that the subscription condition changed.

◆ ~ConditionalSubscriber()

cras::ConditionalSubscriber::~ConditionalSubscriber ( )

virtual

Destroy this object and unsubscribe the subscriber if it was subscribed.

Definition at line 32 of file lazy_subscriber.cpp.

Member Function Documentation

◆ connectNoLock()

void cras::ConditionalSubscriber::connectNoLock ( )

protected

Connect the subscriber to its input.

Note: You have to lock this->connectMutex prior to calling this method.

Definition at line 86 of file lazy_subscriber.cpp.

◆ disconnectNoLock()

void cras::ConditionalSubscriber::disconnectNoLock ( )

protected

Disconnect the subscriber from its input.

Note: You have to lock this->connectMutex prior to calling this method.

Definition at line 93 of file lazy_subscriber.cpp.

◆ isLazy()

bool cras::ConditionalSubscriber::isLazy ( ) const

Tell whether this subscriber has the lazy behavior enabled.

Returns: Whether lazy behavior is enabled.

Definition at line 39 of file lazy_subscriber.cpp.

◆ isSubscribed()

bool cras::ConditionalSubscriber::isSubscribed ( ) const

Whether the subscriber is currently subscribed to its topic or not.

Returns: Whether the subscriber is currently subscribed to its topic or not.

Definition at line 61 of file lazy_subscriber.cpp.

◆ setLazy()

void cras::ConditionalSubscriber::setLazy ( bool lazy )

Set whether the subscriber behaves in the lazy way.

Parameters

[in] lazy If set to false, the subscriber is switched to always subscribed mode.

Note: Calling this function checks the subscription condition and subscribes/unsubscribes as necessary.

Definition at line 44 of file lazy_subscriber.cpp.

◆ shouldBeSubscribed()

virtual bool cras::ConditionalSubscriber::shouldBeSubscribed ( ) const

protectedpure virtual

Tell whether the subscriber should be subscribed or not.

Returns: Whether the subscriber should be subscribed or not.

Note: This function does not need to take into account the lazy flag.; This function cannot lock connectMutex.

Implemented in cras::LazySubscriberBase< PublisherMsgType >, and cras::GenericLazyPubSub.

◆ updateSubscription()

void cras::ConditionalSubscriber::updateSubscription ( )

protected

The callback called when the condition might have changed.

Note: This function locks connectMutex.

Definition at line 67 of file lazy_subscriber.cpp.

◆ updateSubscriptionNoLock()

void cras::ConditionalSubscriber::updateSubscriptionNoLock ( )

protected

The callback called when the condition might have changed.

Note: You have to lock this->connectMutex prior to calling this method.

Definition at line 73 of file lazy_subscriber.cpp.

Member Data Documentation

◆ connectFn

ConnectFn cras::ConditionalSubscriber::connectFn

protected

The function used to establish connection.

Definition at line 135 of file lazy_subscriber.hpp.

◆ connectMutex

mutable ::std::mutex cras::ConditionalSubscriber::connectMutex

protected

Mutex protecting sub and subscribed.

Definition at line 141 of file lazy_subscriber.hpp.

◆ disconnectFn

DisconnectFn cras::ConditionalSubscriber::disconnectFn

protected

The function used to close connection.

Definition at line 138 of file lazy_subscriber.hpp.

◆ lazy

bool cras::ConditionalSubscriber::lazy {true}

protected

Whether the lazy behavior is enabled (if false, the subscriber is always subscribed).

Definition at line 129 of file lazy_subscriber.hpp.

◆ sub

::ros::Subscriber cras::ConditionalSubscriber::sub

protected

The underlying subscriber (valid only when subscribed is true).

Definition at line 126 of file lazy_subscriber.hpp.

◆ subscribed

bool cras::ConditionalSubscriber::subscribed {false}

protected

Whether the subscriber is currently subscribed to its topic or not.

Definition at line 132 of file lazy_subscriber.hpp.

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

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ ConnectFn

◆ DisconnectFn

Constructor & Destructor Documentation

◆ ConditionalSubscriber() [1/2]

◆ ConditionalSubscriber() [2/2]

◆ ~ConditionalSubscriber()

Member Function Documentation

◆ connectNoLock()

◆ disconnectNoLock()

◆ isLazy()

◆ isSubscribed()

◆ setLazy()

◆ shouldBeSubscribed()

◆ updateSubscription()

◆ updateSubscriptionNoLock()

Member Data Documentation

◆ connectFn

◆ connectMutex

◆ disconnectFn

◆ lazy

◆ sub

◆ subscribed