A controller for an individual connection. More...

#include <yarp/os/Connection.h>

Inheritance diagram for yarp::os::Connection:

Public Member Functions
virtual	~Connection ()
	Destructor.

virtual bool	isValid () const
	Check if this object is really a connection, or just an empty placeholder.

virtual bool	isTextMode () const =0
	Check if carrier is textual in nature.

virtual bool	isBareMode () const
	Check if carrier excludes type information from payload.

virtual void	handleEnvelope (const std::string &envelope)=0
	Carriers that do not distinguish data from administrative headers (i.e.

virtual bool	canEscape () const =0
	Check if carrier can encode administrative messages, as opposed to just user data.

virtual bool	requireAck () const =0
	Check if carrier has flow control, requiring sent messages to be acknowledged by recipient.

virtual bool	supportReply () const =0
	This flag is used by YARP to determine whether the connection can carry RPC traffic, that is, messages with replies.

virtual bool	isLocal () const =0
	Check if carrier operates within a single process.

virtual bool	isPush () const =0
	Check if carrier is "push" or "pull" style.

virtual bool	isConnectionless () const =0
	Check if this carrier is connectionless (like udp, mcast) or connection based (like tcp).

virtual bool	isBroadcast () const =0
	Check if this carrier uses a broadcast mechanism.

virtual bool	isActive () const =0
	Check if carrier is alive and error free.

virtual bool	modifiesIncomingData () const =0
	Check if this carrier modifies incoming data through the Carrier::modifyIncomingData method.

virtual yarp::os::ConnectionReader &	modifyIncomingData (yarp::os::ConnectionReader &reader)=0
	Modify incoming payload data, if appropriate.

virtual bool	acceptIncomingData (yarp::os::ConnectionReader &reader)=0
	Determine whether incoming data should be accepted.

virtual bool	modifiesOutgoingData () const =0
	Check if this carrier modifies outgoing data through the Carrier::modifyOutgoingData method.

virtual const PortWriter &	modifyOutgoingData (const PortWriter &writer)=0
	Modify outgoing payload data, if appropriate.

virtual bool	acceptOutgoingData (const PortWriter &writer)=0
	Determine whether outgoing data should be accepted.

virtual bool	modifiesReply () const =0
	Check if this carrier modifies outgoing data through the Carrier::modifyReply method.

virtual PortReader &	modifyReply (PortReader &reader)=0
	Modify reply payload data, if appropriate.

virtual void	setCarrierParams (const yarp::os::Property &params)=0
	Configure carrier from port administrative commands.

virtual void	getCarrierParams (yarp::os::Property &params) const =0
	Get carrier configuration and deliver it by port administrative commands.

virtual void	getHeader (yarp::os::Bytes &header) const =0
	Provide 8 bytes describing this connection sufficiently to allow the other side of a connection to select it.

virtual void	prepareDisconnect ()=0
	Do cleanup and preparation for the coming disconnect, if necessary.

virtual std::string	getName () const =0
	Get the name of this connection type ("tcp", "mcast", "shmem", ...)

Detailed Description

A controller for an individual connection.

A bundle of callbacks that defines how the connection behaves.

Definition at line 25 of file Connection.h.

Constructor & Destructor Documentation

◆ ~Connection()

Connection::~Connection ( )

virtualdefault

Destructor.

Member Function Documentation

◆ acceptIncomingData()

virtual bool yarp::os::Connection::acceptIncomingData ( yarp::os::ConnectionReader & reader )

pure virtual

Determine whether incoming data should be accepted.

Parameters

reader for incoming data.

Returns: true if data should be accepted, false if it should be discarded.

Implemented in yarp::os::Carrier, ForwardingCarrier, PortMonitor, PriorityCarrier, and yarp::os::NullConnection.

◆ acceptOutgoingData()

virtual bool yarp::os::Connection::acceptOutgoingData ( const PortWriter & writer )

pure virtual

Determine whether outgoing data should be accepted.

Parameters

writer for outgoing data.

Returns: true if data should be accepted, false if it should be discarded.

Implemented in yarp::os::Carrier, ForwardingCarrier, yarp::os::NullConnection, and PortMonitor.

◆ canEscape()

virtual bool yarp::os::Connection::canEscape ( ) const

pure virtual

Check if carrier can encode administrative messages, as opposed to just user data.

The word escape is used in the sense of escape character or escape sequence here.

Returns: true if carrier can encode administrative messages

Implemented in GstreamerCarrier, HumanCarrier, MjpegCarrier, MpiCarrier, yarp::os::AbstractCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, ForwardingCarrier, yarp::os::NullConnection, and yarp::os::Carrier.

◆ getCarrierParams()

virtual void yarp::os::Connection::getCarrierParams ( yarp::os::Property & params ) const

pure virtual

Get carrier configuration and deliver it by port administrative commands.

Parameters

params output carrier properties

Implemented in yarp::os::Carrier, ForwardingCarrier, PortMonitor, PriorityCarrier, yarp::os::AbstractCarrier, yarp::os::ModifyingCarrier, and yarp::os::NullConnection.

◆ getHeader()

virtual void yarp::os::Connection::getHeader ( yarp::os::Bytes & header ) const

pure virtual

Provide 8 bytes describing this connection sufficiently to allow the other side of a connection to select it.

Parameters

[out] header a buffer to hold the first 8 bytes to send on a connection

Implemented in HumanCarrier, WebSocketCarrier, yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, yarp::os::impl::TextCarrier, yarp::os::impl::UdpCarrier, yarp::os::Carrier, GstreamerCarrier, MjpegCarrier, MpiCarrier, ShmemCarrier, UnixSocketCarrier, yarp::os::impl::TcpCarrier, yarp::os::ModifyingCarrier, ForwardingCarrier, yarp::os::NullConnection, and yarp::os::AbstractCarrier.

◆ getName()

virtual std::string yarp::os::Connection::getName ( ) const

pure virtual

Get the name of this connection type ("tcp", "mcast", "shmem", ...)

Returns: the name of this connection type

Implemented in BayerCarrier, GstreamerCarrier, HumanCarrier, MjpegCarrier, MpiBcastCarrier, MpiP2PCarrier, PortMonitor, PriorityCarrier, ShmemCarrier, UnixSocketCarrier, WebSocketCarrier, yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::McastCarrier, yarp::os::impl::NameserCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::TextCarrier, yarp::os::impl::UdpCarrier, ForwardingCarrier, yarp::os::NullConnection, MpiCarrier, yarp::os::AbstractCarrier, and yarp::os::ModifyingCarrier.

◆ handleEnvelope()

virtual void yarp::os::Connection::handleEnvelope ( const std::string & envelope )

pure virtual

Carriers that do not distinguish data from administrative headers (i.e.

canEscape returns false), can overload this method to handle the envelope inside the stream. On the receiving side, the InputStream will have to overload the yarp::os::InputStream::setReadEnvelopeCallback method, and execute the callback as soon as the envelope is ready.

Parameters

envelope the envelope to transmit bundled with data.

Implemented in MjpegCarrier, yarp::os::Carrier, ForwardingCarrier, and yarp::os::NullConnection.

◆ isActive()

virtual bool yarp::os::Connection::isActive ( ) const

pure virtual

Check if carrier is alive and error free.

Returns: true if carrier is active.

Implemented in BayerCarrier, GstreamerCarrier, HumanCarrier, MjpegCarrier, MpiBcastCarrier, yarp::os::AbstractCarrier, yarp::os::impl::McastCarrier, ForwardingCarrier, yarp::os::NullConnection, and yarp::os::Carrier.

◆ isBareMode()

bool Connection::isBareMode ( ) const

virtual

Check if carrier excludes type information from payload.

Returns: true if carrier is bare

Reimplemented in BayerCarrier, and ForwardingCarrier.

Definition at line 17 of file Connection.cpp.

◆ isBroadcast()

virtual bool yarp::os::Connection::isBroadcast ( ) const

pure virtual

Check if this carrier uses a broadcast mechanism.

This flag is used to determine whether it is appropriate to send "kill" messages using a carrier or whether they should be sent "out-of-band"

Returns: true if carrier uses a broadcast mechanism.

Implemented in MpiBcastCarrier, yarp::os::Carrier, yarp::os::impl::McastCarrier, ForwardingCarrier, and yarp::os::NullConnection.

◆ isConnectionless()

virtual bool yarp::os::Connection::isConnectionless ( ) const

pure virtual

Check if this carrier is connectionless (like udp, mcast) or connection based (like tcp).

This flag is used by YARP to determine whether the connection can carry RPC traffic, that is, messages with replies. Replies are not supported by YARP on connectionless carriers.

Returns: true if carrier is connectionless

Implemented in GstreamerCarrier, HumanCarrier, MjpegCarrier, MpiCarrier, ShmemCarrier, UnixSocketCarrier, yarp::os::AbstractCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::UdpCarrier, ForwardingCarrier, yarp::os::NullConnection, and yarp::os::Carrier.

◆ isLocal()

virtual bool yarp::os::Connection::isLocal ( ) const

pure virtual

Check if carrier operates within a single process.

In such a case, YARP connections may get completely reorganized in order to optimize them.

Returns: true if carrier will only operate within a single process

Implemented in GstreamerCarrier, HumanCarrier, MjpegCarrier, yarp::os::AbstractCarrier, yarp::os::impl::LocalCarrier, ForwardingCarrier, yarp::os::NullConnection, and yarp::os::Carrier.

◆ isPush()

virtual bool yarp::os::Connection::isPush ( ) const

pure virtual

Check if carrier is "push" or "pull" style.

Push means that the side that initiates a connection is also the one that will sending of data or commands. All native YARP connections are like this. A "pull" style is equivalent to automatically sending a "reverse connection" port command at the start of the connection.

Returns: true if carrier is "push" style, false if "pull" style

Implemented in GstreamerCarrier, MjpegCarrier, yarp::os::Carrier, ForwardingCarrier, and yarp::os::NullConnection.

◆ isTextMode()

virtual bool yarp::os::Connection::isTextMode ( ) const

pure virtual

Check if carrier is textual in nature.

Returns: true if carrier is text-based

Implemented in BayerCarrier, GstreamerCarrier, HumanCarrier, MjpegCarrier, WebSocketCarrier, yarp::os::AbstractCarrier, yarp::os::impl::HttpCarrier, yarp::os::impl::NameserCarrier, yarp::os::impl::TextCarrier, ForwardingCarrier, yarp::os::NullConnection, and yarp::os::Carrier.

◆ isValid()

bool Connection::isValid ( ) const

virtual

Check if this object is really a connection, or just an empty placeholder.

Returns: true if a valid connection

Reimplemented in BayerCarrier, ForwardingCarrier, and yarp::os::NullConnection.

Definition at line 12 of file Connection.cpp.

◆ modifiesIncomingData()

virtual bool yarp::os::Connection::modifiesIncomingData ( ) const

pure virtual

Check if this carrier modifies incoming data through the Carrier::modifyIncomingData method.

Returns: true if carrier wants Carrier::modifyIncomingData called.

Implemented in yarp::os::Carrier, yarp::os::ModifyingCarrier, ForwardingCarrier, and yarp::os::NullConnection.

◆ modifiesOutgoingData()

virtual bool yarp::os::Connection::modifiesOutgoingData ( ) const

pure virtual

Check if this carrier modifies outgoing data through the Carrier::modifyOutgoingData method.

Returns: true if carrier wants Carrier::modifyOutgoingData called.

Implemented in yarp::os::Carrier, yarp::os::ModifyingCarrier, ForwardingCarrier, and yarp::os::NullConnection.

◆ modifiesReply()

virtual bool yarp::os::Connection::modifiesReply ( ) const

pure virtual

Check if this carrier modifies outgoing data through the Carrier::modifyReply method.

Returns: true if carrier wants Carrier::modifyReply called.

Implemented in yarp::os::Carrier, yarp::os::ModifyingCarrier, ForwardingCarrier, and yarp::os::NullConnection.

◆ modifyIncomingData()

virtual yarp::os::ConnectionReader & yarp::os::Connection::modifyIncomingData ( yarp::os::ConnectionReader & reader )

pure virtual

Modify incoming payload data, if appropriate.

Doesn't need to be done immediately, it is fine to hold onto a reference to the incoming data reader and use it on demand. This can be handy in order to avoid unnecessary copies.

Parameters

reader for incoming data.

Returns: reader for modified version of incoming data.

Implemented in yarp::os::Carrier, ForwardingCarrier, BayerCarrier, PortMonitor, and yarp::os::NullConnection.

◆ modifyOutgoingData()

virtual const PortWriter & yarp::os::Connection::modifyOutgoingData ( const PortWriter & writer )

pure virtual

Modify outgoing payload data, if appropriate.

Doesn't need to be done immediately, it is fine to hold onto a reference to the outgoing data reader and use it on demand. This can be handy in order to avoid unnecessary copies.

Parameters

writer for outgoing data.

Returns: writer for modified version of outgoing data.

Implemented in yarp::os::Carrier, ForwardingCarrier, yarp::os::NullConnection, and PortMonitor.

◆ modifyReply()

virtual PortReader & yarp::os::Connection::modifyReply ( PortReader & reader )

pure virtual

Modify reply payload data, if appropriate.

Parameters

reader for the replied message.

Returns: reader for modified version of the replied message.

Implemented in yarp::os::Carrier, ForwardingCarrier, yarp::os::NullConnection, and PortMonitor.

◆ prepareDisconnect()

virtual void yarp::os::Connection::prepareDisconnect ( )

pure virtual

Do cleanup and preparation for the coming disconnect, if necessary.

Implemented in MpiBcastCarrier, yarp::os::Carrier, ForwardingCarrier, and yarp::os::NullConnection.

◆ requireAck()

virtual bool yarp::os::Connection::requireAck ( ) const

pure virtual

Check if carrier has flow control, requiring sent messages to be acknowledged by recipient.

Returns: true if carrier requires acknowledgement.

Implemented in GstreamerCarrier, HumanCarrier, MjpegCarrier, ShmemCarrier, UnixSocketCarrier, WebSocketCarrier, yarp::os::AbstractCarrier, yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::TextCarrier, yarp::os::impl::UdpCarrier, ForwardingCarrier, yarp::os::NullConnection, and yarp::os::Carrier.

◆ setCarrierParams()

virtual void yarp::os::Connection::setCarrierParams ( const yarp::os::Property & params )

pure virtual

Configure carrier from port administrative commands.

Parameters

params carrier properties

Implemented in yarp::os::Carrier, ForwardingCarrier, PortMonitor, PriorityCarrier, yarp::os::AbstractCarrier, yarp::os::ModifyingCarrier, and yarp::os::NullConnection.

◆ supportReply()

virtual bool yarp::os::Connection::supportReply ( ) const

pure virtual

This flag is used by YARP to determine whether the connection can carry RPC traffic, that is, messages with replies.

Returns: true if carrier supports replies

Implemented in GstreamerCarrier, HumanCarrier, MjpegCarrier, MpiBcastCarrier, MpiP2PCarrier, WebSocketCarrier, yarp::os::AbstractCarrier, yarp::os::impl::HttpCarrier, yarp::os::impl::NameserCarrier, yarp::os::impl::TextCarrier, ForwardingCarrier, yarp::os::NullConnection, MpiCarrier, and yarp::os::Carrier.

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

src/libYARP_os/src/yarp/os/Connection.h
src/libYARP_os/src/yarp/os/Connection.cpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ ~Connection()

Member Function Documentation

◆ acceptIncomingData()

◆ acceptOutgoingData()

◆ canEscape()

◆ getCarrierParams()

◆ getHeader()

◆ getName()

◆ handleEnvelope()

◆ isActive()

◆ isBareMode()

◆ isBroadcast()

◆ isConnectionless()

◆ isLocal()

◆ isPush()

◆ isTextMode()

◆ isValid()

◆ modifiesIncomingData()

◆ modifiesOutgoingData()

◆ modifiesReply()

◆ modifyIncomingData()

◆ modifyOutgoingData()

◆ modifyReply()

◆ prepareDisconnect()

◆ requireAck()

◆ setCarrierParams()

◆ supportReply()