YARP
Yet Another Robot Platform
yarp::os::AbstractCarrier Class Referenceabstract

A starter class for implementing simple carriers. More...

#include <yarp/os/AbstractCarrier.h>

+ Inheritance diagram for yarp::os::AbstractCarrier:

Detailed Description

A starter class for implementing simple carriers.

It implements reasonable default behavior.

Definition at line 29 of file AbstractCarrier.h.

Public Member Functions

virtual Carriercreate () const override=0
 Factory method. More...
 
virtual std::string getName () const override=0
 Get the name of this connection type ("tcp", "mcast", "shmem", ...) More...
 
virtual bool checkHeader (const yarp::os::Bytes &header) override=0
 Given the first 8 bytes received on a connection, decide if this is the right carrier type to use for the rest of the connection. More...
 
virtual void setParameters (const yarp::os::Bytes &header) override
 Configure this carrier based on the first 8 bytes of the connection. More...
 
virtual void getHeader (yarp::os::Bytes &header) const override=0
 Provide 8 bytes describing this connection sufficiently to allow the other side of a connection to select it. More...
 
virtual void setCarrierParams (const yarp::os::Property &params) override
 Configure carrier from port administrative commands. More...
 
virtual void getCarrierParams (yarp::os::Property &params) const override
 Get carrier configuration and deliver it by port administrative commands. More...
 
virtual bool isConnectionless () const override
 Check if this carrier is connectionless (like udp, mcast) or connection based (like tcp). More...
 
virtual bool supportReply () const override
 This flag is used by YARP to determine whether the connection can carry RPC traffic, that is, messages with replies. More...
 
virtual bool canAccept () const override
 Check if reading is implemented for this carrier. More...
 
virtual bool canOffer () const override
 Check if writing is implemented for this carrier. More...
 
virtual bool isTextMode () const override
 Check if carrier is textual in nature. More...
 
virtual bool requireAck () const override
 Check if carrier has flow control, requiring sent messages to be acknowledged by recipient. More...
 
virtual bool canEscape () const override
 Check if carrier can encode administrative messages, as opposed to just user data. More...
 
virtual bool isLocal () const override
 Check if carrier operates within a single process. More...
 
virtual std::string toString () const override
 Get name of carrier. More...
 
virtual bool isActive () const override
 Check if carrier is alive and error free. More...
 
virtual bool prepareSend (ConnectionState &proto) override
 Perform any initialization needed before writing on a connection. More...
 
virtual bool sendHeader (ConnectionState &proto) override
 Write a header appropriate to the carrier to the connection, followed by any carrier-specific data. More...
 
virtual bool expectReplyToHeader (ConnectionState &proto) override
 Process reply to header, if one is expected for this carrier. More...
 
virtual bool sendIndex (ConnectionState &proto, SizedWriter &writer)
 
virtual bool expectExtraHeader (ConnectionState &proto) override
 Receive any carrier-specific header. More...
 
virtual bool respondToHeader (ConnectionState &proto) override=0
 Respond to the header. More...
 
virtual bool expectIndex (ConnectionState &proto) override
 Expect a message header, if there is one for this carrier. More...
 
virtual bool expectSenderSpecifier (ConnectionState &proto) override
 Expect the name of the sending port. More...
 
virtual bool sendAck (ConnectionState &proto) override
 Send an acknowledgement, if needed for this carrier. More...
 
virtual bool expectAck (ConnectionState &proto) override
 Receive an acknowledgement, if expected for this carrier. More...
 
bool defaultSendHeader (ConnectionState &proto)
 Default implementation for the sendHeader method. More...
 
bool defaultExpectIndex (ConnectionState &proto)
 Default implementation for the expectIndex method. More...
 
bool defaultSendIndex (ConnectionState &proto, SizedWriter &writer)
 Default implementation for the sendIndex method. More...
 
bool defaultExpectAck (ConnectionState &proto)
 Default implementation for the expectAck method. More...
 
bool defaultSendAck (ConnectionState &proto)
 Default implementation for the sendAck method. More...
 
int readYarpInt (ConnectionState &proto)
 Read 8 bytes and interpret them as a YARP number. More...
 
void writeYarpInt (int n, ConnectionState &proto)
 Write n as an 8 bytes yarp number. More...
 
- Public Member Functions inherited from yarp::os::Carrier
virtual bool isBroadcast () const override
 Check if this carrier uses a broadcast mechanism. More...
 
virtual void handleEnvelope (const std::string &envelope) override
 Carriers that do not distinguish data from administrative headers (i.e. More...
 
virtual bool isPush () const override
 Check if carrier is "push" or "pull" style. More...
 
virtual bool reply (ConnectionState &proto, SizedWriter &writer)
 
virtual void prepareDisconnect () override
 Do cleanup and preparation for the coming disconnect, if necessary. More...
 
virtual void close ()
 Close the carrier. More...
 
virtual ~Carrier ()
 Destructor. More...
 
virtual std::string getBootstrapCarrierName () const
 Get the name of the carrier that should be used prior to handshaking, if a port is registered with this carrier as its default carrier. More...
 
virtual int connect (const Contact &src, const Contact &dest, const ContactStyle &style, int mode, bool reversed)
 Some carrier types may require special connection logic. More...
 
virtual bool modifiesIncomingData () const override
 Check if this carrier modifies incoming data through the Carrier::modifyIncomingData method. More...
 
virtual ConnectionReadermodifyIncomingData (ConnectionReader &reader) override
 Modify incoming payload data, if appropriate. More...
 
virtual bool acceptIncomingData (ConnectionReader &reader) override
 Determine whether incoming data should be accepted. More...
 
virtual bool modifiesOutgoingData () const override
 Check if this carrier modifies outgoing data through the Carrier::modifyOutgoingData method. More...
 
virtual const PortWritermodifyOutgoingData (const PortWriter &writer) override
 Modify outgoing payload data, if appropriate. More...
 
virtual bool modifiesReply () const override
 Check if this carrier modifies outgoing data through the Carrier::modifyReply method. More...
 
virtual PortReadermodifyReply (PortReader &reader) override
 Modify reply payload data, if appropriate. More...
 
virtual bool acceptOutgoingData (const PortWriter &writer) override
 Determine whether outgoing data should be accepted. More...
 
virtual bool configure (ConnectionState &proto)
 Give carrier a shot at looking at how the connection is set up. More...
 
virtual bool configureFromProperty (yarp::os::Property &options)
 
virtual yarp::os::FacecreateFace () const
 Create new Face object that the carrier needs. More...
 
- Public Member Functions inherited from yarp::os::Connection
virtual ~Connection ()
 Destructor. More...
 
virtual bool isValid () const
 Check if this object is really a connection, or just an empty placeholder. More...
 
virtual bool isBareMode () const
 Check if carrier excludes type information from payload. More...
 

Protected Member Functions

int getSpecifier (const Bytes &b) const
 
void createStandardHeader (int specifier, yarp::os::Bytes &header) const
 
virtual bool write (ConnectionState &proto, SizedWriter &writer) override
 Write a message. More...
 
bool sendConnectionStateSpecifier (ConnectionState &proto)
 
bool sendSenderSpecifier (ConnectionState &proto)
 

Static Protected Member Functions

static int interpretYarpNumber (const yarp::os::Bytes &b)
 
static void createYarpNumber (int x, yarp::os::Bytes &header)
 

Member Function Documentation

◆ canAccept()

bool AbstractCarrier::canAccept ( ) const
overridevirtual

Check if reading is implemented for this carrier.

Returns
true if carrier can read messages

Implements yarp::os::Carrier.

Definition at line 34 of file AbstractCarrier.cpp.

◆ canEscape()

bool AbstractCarrier::canEscape ( ) const
overridevirtual

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

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, and yarp::os::MpiCarrier.

Definition at line 54 of file AbstractCarrier.cpp.

◆ canOffer()

bool AbstractCarrier::canOffer ( ) const
overridevirtual

Check if writing is implemented for this carrier.

Returns
true if carrier can write messages

Implements yarp::os::Carrier.

Definition at line 39 of file AbstractCarrier.cpp.

◆ checkHeader()

virtual bool yarp::os::AbstractCarrier::checkHeader ( const yarp::os::Bytes header)
overridepure virtual

Given the first 8 bytes received on a connection, decide if this is the right carrier type to use for the rest of the connection.

For example the "text" carrier looks for the 8-byte sequence "CONNECT ". See the YARP protocol documentation for all the sequences in use here. In general you are free to add your own.

Parameters
headera buffer holding the first 8 bytes received on the connection
Returns
true if this is the carrier to use.

Implements yarp::os::Carrier.

Implemented in yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, yarp::os::MpiCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::UdpCarrier, yarp::os::impl::TextCarrier, yarp::os::ModifyingCarrier, and ShmemCarrier.

◆ create()

◆ createStandardHeader()

void AbstractCarrier::createStandardHeader ( int  specifier,
yarp::os::Bytes header 
) const
protected

Definition at line 168 of file AbstractCarrier.cpp.

◆ createYarpNumber()

void AbstractCarrier::createYarpNumber ( int  x,
yarp::os::Bytes header 
)
staticprotected

Definition at line 378 of file AbstractCarrier.cpp.

◆ defaultExpectAck()

bool AbstractCarrier::defaultExpectAck ( ConnectionState proto)

Default implementation for the expectAck method.

Definition at line 240 of file AbstractCarrier.cpp.

◆ defaultExpectIndex()

bool AbstractCarrier::defaultExpectIndex ( ConnectionState proto)

Default implementation for the expectIndex method.

Definition at line 264 of file AbstractCarrier.cpp.

◆ defaultSendAck()

bool AbstractCarrier::defaultSendAck ( ConnectionState proto)

Default implementation for the sendAck method.

Definition at line 333 of file AbstractCarrier.cpp.

◆ defaultSendHeader()

bool AbstractCarrier::defaultSendHeader ( ConnectionState proto)

Default implementation for the sendHeader method.

Definition at line 184 of file AbstractCarrier.cpp.

◆ defaultSendIndex()

bool AbstractCarrier::defaultSendIndex ( ConnectionState proto,
SizedWriter writer 
)

Default implementation for the sendIndex method.

Definition at line 219 of file AbstractCarrier.cpp.

◆ expectAck()

bool AbstractCarrier::expectAck ( ConnectionState proto)
overridevirtual

Receive an acknowledgement, if expected for this carrier.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::MpiCarrier, yarp::os::impl::NameserCarrier, and yarp::os::impl::TextCarrier.

Definition at line 139 of file AbstractCarrier.cpp.

◆ expectExtraHeader()

bool AbstractCarrier::expectExtraHeader ( ConnectionState proto)
overridevirtual

Receive any carrier-specific header.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::LocalCarrier, and yarp::os::impl::McastCarrier.

Definition at line 92 of file AbstractCarrier.cpp.

◆ expectIndex()

bool AbstractCarrier::expectIndex ( ConnectionState proto)
overridevirtual

Expect a message header, if there is one for this carrier.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, yarp::os::MpiCarrier, and yarp::os::impl::TextCarrier.

Definition at line 98 of file AbstractCarrier.cpp.

◆ expectReplyToHeader()

bool AbstractCarrier::expectReplyToHeader ( ConnectionState proto)
overridevirtual

Process reply to header, if one is expected for this carrier.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, yarp::os::MpiBcastCarrier, yarp::os::MpiCarrier, yarp::os::impl::McastCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::UdpCarrier, yarp::os::impl::TextCarrier, and ShmemCarrier.

Definition at line 81 of file AbstractCarrier.cpp.

◆ expectSenderSpecifier()

bool AbstractCarrier::expectSenderSpecifier ( ConnectionState proto)
overridevirtual

Expect the name of the sending port.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::impl::NameserCarrier, yarp::os::MpiCarrier, and yarp::os::impl::TextCarrier.

Definition at line 103 of file AbstractCarrier.cpp.

◆ getCarrierParams()

void AbstractCarrier::getCarrierParams ( yarp::os::Property params) const
overridevirtual

Get carrier configuration and deliver it by port administrative commands.

Parameters
paramsproperties

Reimplemented from yarp::os::Carrier.

Reimplemented in yarp::os::PriorityCarrier, yarp::os::PortMonitor, and yarp::os::ModifyingCarrier.

Definition at line 154 of file AbstractCarrier.cpp.

◆ getHeader()

virtual void yarp::os::AbstractCarrier::getHeader ( yarp::os::Bytes header) const
overridepure virtual

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

Parameters
headera buffer to hold the first 8 bytes to send on a connection

Implements yarp::os::Carrier.

Implemented in yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, yarp::os::MpiCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::UdpCarrier, yarp::os::impl::TextCarrier, yarp::os::ModifyingCarrier, and ShmemCarrier.

◆ getName()

◆ getSpecifier()

int AbstractCarrier::getSpecifier ( const Bytes b) const
protected

Definition at line 159 of file AbstractCarrier.cpp.

◆ interpretYarpNumber()

int AbstractCarrier::interpretYarpNumber ( const yarp::os::Bytes b)
staticprotected

Definition at line 362 of file AbstractCarrier.cpp.

◆ isActive()

bool AbstractCarrier::isActive ( ) const
overridevirtual

Check if carrier is alive and error free.

Returns
true if carrier is active.

Implements yarp::os::Carrier.

Reimplemented in yarp::os::BayerCarrier, yarp::os::MpiBcastCarrier, and yarp::os::impl::McastCarrier.

Definition at line 144 of file AbstractCarrier.cpp.

◆ isConnectionless()

bool AbstractCarrier::isConnectionless ( ) const
overridevirtual

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

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::LocalCarrier, yarp::os::MpiCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::UdpCarrier, and ShmemCarrier.

Definition at line 23 of file AbstractCarrier.cpp.

◆ isLocal()

bool AbstractCarrier::isLocal ( ) const
overridevirtual

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

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::LocalCarrier.

Definition at line 59 of file AbstractCarrier.cpp.

◆ isTextMode()

bool AbstractCarrier::isTextMode ( ) const
overridevirtual

Check if carrier is textual in nature.

Returns
true if carrier is text-based

Implements yarp::os::Carrier.

Reimplemented in yarp::os::BayerCarrier, yarp::os::impl::HttpCarrier, yarp::os::impl::NameserCarrier, and yarp::os::impl::TextCarrier.

Definition at line 44 of file AbstractCarrier.cpp.

◆ prepareSend()

bool AbstractCarrier::prepareSend ( ConnectionState proto)
overridevirtual

Perform any initialization needed before writing on a connection.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Definition at line 69 of file AbstractCarrier.cpp.

◆ readYarpInt()

int AbstractCarrier::readYarpInt ( ConnectionState proto)

Read 8 bytes and interpret them as a YARP number.

Definition at line 342 of file AbstractCarrier.cpp.

◆ requireAck()

bool AbstractCarrier::requireAck ( ) const
overridevirtual

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

Returns
true if carrier requires acknowledgement.

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::UdpCarrier, yarp::os::impl::TextCarrier, and ShmemCarrier.

Definition at line 49 of file AbstractCarrier.cpp.

◆ respondToHeader()

virtual bool yarp::os::AbstractCarrier::respondToHeader ( ConnectionState proto)
overridepure virtual

Respond to the header.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Implemented in yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, yarp::os::MpiCarrier, yarp::os::impl::McastCarrier, yarp::os::impl::TextCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::UdpCarrier, ShmemCarrier, and yarp::os::ModifyingCarrier.

◆ sendAck()

bool AbstractCarrier::sendAck ( ConnectionState proto)
overridevirtual

Send an acknowledgement, if needed for this carrier.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::MpiCarrier, yarp::os::impl::NameserCarrier, and yarp::os::impl::TextCarrier.

Definition at line 134 of file AbstractCarrier.cpp.

◆ sendConnectionStateSpecifier()

bool AbstractCarrier::sendConnectionStateSpecifier ( ConnectionState proto)
protected

Definition at line 193 of file AbstractCarrier.cpp.

◆ sendHeader()

bool AbstractCarrier::sendHeader ( ConnectionState proto)
overridevirtual

Write a header appropriate to the carrier to the connection, followed by any carrier-specific data.

Must communicate at least the name of the originating port, if there is one.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, yarp::os::MpiCarrier, yarp::os::impl::McastCarrier, and yarp::os::impl::TextCarrier.

Definition at line 75 of file AbstractCarrier.cpp.

◆ sendIndex()

bool AbstractCarrier::sendIndex ( ConnectionState proto,
SizedWriter writer 
)
virtual

◆ sendSenderSpecifier()

bool AbstractCarrier::sendSenderSpecifier ( ConnectionState proto)
protected

Definition at line 204 of file AbstractCarrier.cpp.

◆ setCarrierParams()

void AbstractCarrier::setCarrierParams ( const yarp::os::Property params)
overridevirtual

Configure carrier from port administrative commands.

Parameters
paramsproperties

Reimplemented from yarp::os::Carrier.

Reimplemented in yarp::os::PriorityCarrier, yarp::os::PortMonitor, and yarp::os::ModifyingCarrier.

Definition at line 149 of file AbstractCarrier.cpp.

◆ setParameters()

void AbstractCarrier::setParameters ( const yarp::os::Bytes header)
overridevirtual

Configure this carrier based on the first 8 bytes of the connection.

This will only be called if checkHeader passed.

Parameters
headera buffer holding the first 8 bytes received on the connection

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::TcpCarrier, yarp::os::impl::UdpCarrier, and ShmemCarrier.

Definition at line 17 of file AbstractCarrier.cpp.

◆ supportReply()

bool AbstractCarrier::supportReply ( ) const
overridevirtual

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

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::impl::NameserCarrier, yarp::os::MpiBcastCarrier, yarp::os::MpiP2PCarrier, yarp::os::MpiCarrier, and yarp::os::impl::TextCarrier.

Definition at line 29 of file AbstractCarrier.cpp.

◆ toString()

std::string AbstractCarrier::toString ( ) const
overridevirtual

Get name of carrier.

Returns
name of carrier.

Implements yarp::os::Carrier.

Reimplemented in yarp::os::PriorityCarrier, yarp::os::BayerCarrier, and yarp::os::PortMonitor.

Definition at line 64 of file AbstractCarrier.cpp.

◆ write()

bool AbstractCarrier::write ( ConnectionState proto,
SizedWriter writer 
)
overrideprotectedvirtual

Write a message.

Parameters
protothe protocol object, which tracks connection state
Returns
true on success, false on failure

Implements yarp::os::Carrier.

Reimplemented in yarp::os::impl::HttpCarrier, yarp::os::impl::LocalCarrier, yarp::os::impl::NameserCarrier, and yarp::os::MpiCarrier.

Definition at line 173 of file AbstractCarrier.cpp.

◆ writeYarpInt()

void AbstractCarrier::writeYarpInt ( int  n,
ConnectionState proto 
)

Write n as an 8 bytes yarp number.

Definition at line 354 of file AbstractCarrier.cpp.


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