ISubscriptionHandler Class Reference

Interface class used to manage generic protobuf messages. More...

#include <SubscriptionHandler.hh>

Public Types
using	MsgFactory = std::function< std::shared_ptr< ProtoMsg >(const char *_data, std::size_t _size, const std::string &_type)>
	Function type that deserializes a raw buffer into a message.

Public Member Functions
	ISubscriptionHandler (const std::string &_pUuid, const std::string &_nUuid, const SubscribeOptions &_opts=SubscribeOptions())
	Constructor.
virtual	~ISubscriptionHandler ()=default
	Destructor.
virtual const std::shared_ptr< ProtoMsg >	CreateMsg (const std::string &_data, const std::string &_type) const =0
	Create a specific protobuf message given its serialized data.
const std::shared_ptr< ProtoMsg >	CreateMsgFromBuffer (const char *_data, std::size_t _size, const std::string &_type) const
	Create a protobuf message from a raw buffer. Avoids a string copy compared to CreateMsg when the data already lives in a contiguous buffer (e.g. Zenoh SHM). Dispatches to the deserializer registered with SetMsgFactory(); when none was registered (e.g. a handler compiled against older headers), falls back to a string copy + the virtual CreateMsg. Deliberately non-virtual: a new virtual function would change the vtable layout and break ABI within a major release.
virtual bool	RunLocalCallback (const ProtoMsg &_msg, const MessageInfo &_info)=0
	Executes the local callback registered for this handler.
Public Member Functions inherited from SubscriptionHandlerBase
	SubscriptionHandlerBase (const std::string &_pUuid, const std::string &_nUuid, const SubscribeOptions &_opts=SubscribeOptions())
	Constructor.
virtual	~SubscriptionHandlerBase ()
	Destructor.
std::string	HandlerUuid () const
	Get the unique UUID of this handler.
bool	IgnoreLocalMessages () const
	Return whether local messages are ignored or not.
std::string	NodeUuid () const
	Get the node UUID.
std::string	ProcUuid () const
	Get the process UUID.
virtual std::string	TypeName ()=0
	Get the type of the messages from which this subscriber handler is subscribed.

Protected Member Functions
void	SetMsgFactory (MsgFactory _factory)
	Register the deserializer used by CreateMsgFromBuffer(). Concrete handlers call this on construction. A CreateMsg override may only delegate to CreateMsgFromBuffer() when a factory has been registered; otherwise the fallback path would recurse.
Protected Member Functions inherited from SubscriptionHandlerBase
bool	UpdateThrottling ()
	Check if message subscription is throttled. If so, verify whether the callback should be executed or not.

Additional Inherited Members
Protected Attributes inherited from SubscriptionHandlerBase
std::unique_ptr< SubscriptionHandlerBasePrivate >	dataPtr
	Private data.
SubscribeOptions	opts
	Subscribe options.
double	periodNs
	If throttling is enabled, the minimum period for receiving a message in nanoseconds.

Detailed Description

Interface class used to manage generic protobuf messages.

gz/transport/SubscriptionHandler.hh

This extends SubscriptionHandlerBase by defining virtual functions for deserializing protobuf message data, and for receiving deserialized messages. Those functions are not needed by the RawSubscriptionHandler class.

Member Typedef Documentation

MsgFactory

using MsgFactory = std::function<std::shared_ptr<ProtoMsg>( const char *_data, std::size_t _size, const std::string &_type)>

Function type that deserializes a raw buffer into a message.

See also

SetMsgFactory

Constructor & Destructor Documentation

ISubscriptionHandler()

ISubscriptionHandler ( const std::string &  _pUuid, const std::string &  _nUuid, const SubscribeOptions &  _opts = SubscribeOptions()  )

explicit

Constructor.

Parameters

[in]	_pUuid	UUID of the process registering the handler.
[in]	_nUuid	UUID of the node registering the handler.
[in]	_opts	Subscription options.

~ISubscriptionHandler()

virtual ~ISubscriptionHandler ( )

virtualdefault

Destructor.

Member Function Documentation

CreateMsg()

virtual const std::shared_ptr< ProtoMsg > CreateMsg ( const std::string &  _data, const std::string &  _type  ) const

pure virtual

Create a specific protobuf message given its serialized data.

Parameters

[in]	_data	The serialized data.
[in]	_type	The data type.

Returns

Pointer to the specific protobuf message.

Implemented in SubscriptionHandler< T >, and SubscriptionHandler< ProtoMsg >.

CreateMsgFromBuffer()

const std::shared_ptr< ProtoMsg > CreateMsgFromBuffer	(	const char *	_data,
		std::size_t	_size,
		const std::string &	_type
	)		const

Create a protobuf message from a raw buffer. Avoids a string copy compared to CreateMsg when the data already lives in a contiguous buffer (e.g. Zenoh SHM). Dispatches to the deserializer registered with SetMsgFactory(); when none was registered (e.g. a handler compiled against older headers), falls back to a string copy + the virtual CreateMsg. Deliberately non-virtual: a new virtual function would change the vtable layout and break ABI within a major release.

Parameters

[in]	_data	Pointer to the serialized data.
[in]	_size	Number of bytes in _data.
[in]	_type	The data type.

Returns

Pointer to the specific protobuf message.

Referenced by SubscriptionHandler< T >::CreateMsg(), and SubscriptionHandler< ProtoMsg >::CreateMsg().

RunLocalCallback()

virtual bool RunLocalCallback ( const ProtoMsg &  _msg, const MessageInfo &  _info  )

pure virtual

Executes the local callback registered for this handler.

Parameters

[in]	_msg	Protobuf message received.
[in]	_info	Message information (e.g.: topic name).

Returns

True when success, false otherwise.

Implemented in SubscriptionHandler< T >, and SubscriptionHandler< ProtoMsg >.

SetMsgFactory()

void SetMsgFactory ( MsgFactory  _factory )

protected

Register the deserializer used by CreateMsgFromBuffer(). Concrete handlers call this on construction. A CreateMsg override may only delegate to CreateMsgFromBuffer() when a factory has been registered; otherwise the fallback path would recurse.

Parameters

[in]

_factory

The deserializer.

Referenced by SubscriptionHandler< T >::SubscriptionHandler(), and SubscriptionHandler< ProtoMsg >::SubscriptionHandler().

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

• SubscriptionHandler.hh