The Face class provides the main methods for NDN communication. More...

#include <face.hpp>

Public Member Functions
	Face (const ptr_lib::shared_ptr< Transport > &transport, const ptr_lib::shared_ptr< const Transport::ConnectionInfo > &connectionInfo)
	Create a new Face for communication with an NDN hub with the given Transport object and connectionInfo. More...

	Face (const char *host, unsigned short port=6363)
	Create a new Face for communication with an NDN hub at host:port using the default TcpTransport. More...

	Face ()
	Create a new Face for communication with an NDN hub using a default connection as follows. More...

uint64_t	expressInterest (const Interest &interest, const OnData &onData, const OnTimeout &onTimeout=OnTimeout(), WireFormat &wireFormat=*WireFormat::getDefaultWireFormat())
	Send the Interest through the transport, read the entire response and call onData(interest, data). More...

uint64_t	expressInterest (const Name &name, const Interest interestTemplate, const OnData &onData, const OnTimeout &onTimeout=OnTimeout(), WireFormat &wireFormat=WireFormat::getDefaultWireFormat())
	Encode name as an Interest. More...

uint64_t	expressInterest (const Name &name, const OnData &onData, const OnTimeout &onTimeout=OnTimeout(), WireFormat &wireFormat=*WireFormat::getDefaultWireFormat())
	Encode name as an Interest, using a default interest lifetime. More...

void	removePendingInterest (uint64_t pendingInterestId)
	Remove the pending interest entry with the pendingInterestId from the pending interest table. More...

void	setCommandSigningInfo (KeyChain &keyChain, const Name &certificateName)
	Set the KeyChain and certificate name used to sign command interests (e.g. More...

void	setCommandCertificateName (const Name &certificateName)
	Set the certificate name used to sign command interest (e.g. More...

void	makeCommandInterest (Interest &interest, WireFormat &wireFormat=*WireFormat::getDefaultWireFormat())
	Append a timestamp component and a random value component to interest's name. More...

uint64_t	registerPrefix (const Name &prefix, const OnInterestCallback &onInterest, const OnRegisterFailed &onRegisterFailed, const ForwardingFlags &flags=ForwardingFlags(), WireFormat &wireFormat=*WireFormat::getDefaultWireFormat())
	Register prefix with the connected NDN hub and call onInterest when a matching interest is received. More...

uint64_t DEPRECATED_IN_NDN_CPP	registerPrefix (const Name &prefix, const OnInterest &onInterest, const OnRegisterFailed &onRegisterFailed, const ForwardingFlags &flags=ForwardingFlags(), WireFormat &wireFormat=*WireFormat::getDefaultWireFormat())

void	removeRegisteredPrefix (uint64_t registeredPrefixId)
	Remove the registered prefix entry with the registeredPrefixId from the registered prefix table. More...

uint64_t	setInterestFilter (const InterestFilter &filter, const OnInterestCallback &onInterest)
	Add an entry to the local interest filter table to call the onInterest callback for a matching incoming Interest. More...

uint64_t	setInterestFilter (const Name &prefix, const OnInterestCallback &onInterest)
	Add an entry to the local interest filter table to call the onInterest callback for a matching incoming Interest. More...

void	unsetInterestFilter (uint64_t interestFilterId)
	Remove the interest filter entry which has the interestFilterId from the interest filter table. More...

void	putData (const Data &data, WireFormat &wireFormat=*WireFormat::getDefaultWireFormat())
	The OnInterestCallback calls this to put a Data packet which satisfies an Interest. More...

void	send (const Blob &encoding)
	Send the encoded packet out through the face. More...

void	send (const uint8_t *encoding, size_t encodingLength)
	Send the encoded packet out through the face. More...

void	processEvents ()
	Process any packets to receive and call callbacks such as onData, onInterest or onTimeout. More...

bool	isLocal ()
	Check if the face is local based on the current connection through the Transport; some Transport may cause network I/O (e.g. More...

void	shutdown ()
	Shut down and disconnect this Face.

Static Public Member Functions
static size_t	getMaxNdnPacketSize ()
	Get the practical limit of the size of a network-layer packet. More...

Detailed Description

The Face class provides the main methods for NDN communication.

Constructor & Destructor Documentation

ndn::Face::Face	(	const ptr_lib::shared_ptr< Transport > &	transport,
		const ptr_lib::shared_ptr< const Transport::ConnectionInfo > &	connectionInfo
	)

Create a new Face for communication with an NDN hub with the given Transport object and connectionInfo.

Parameters

transport	A shared_ptr to a Transport object used for communication.
transport	A shared_ptr to a Transport::ConnectionInfo to be used to connect to the transport.

ndn::Face::Face	(	const char *	host,
		unsigned short	port = `6363`
	)

Create a new Face for communication with an NDN hub at host:port using the default TcpTransport.

Parameters

host	The host of the NDN hub.
port	(optional) The port of the NDN hub. If omitted. use 6363.

ndn::Face::Face ( )

Create a new Face for communication with an NDN hub using a default connection as follows.

If the forwarder's Unix socket file exists, then connect using UnixTransport. Otherwise, connect to "localhost" on port 6363 using TcpTransport.

Member Function Documentation

uint64_t ndn::Face::expressInterest	(	const Interest &	interest,
		const OnData &	onData,
		const OnTimeout &	onTimeout = `OnTimeout()`,
		WireFormat &	wireFormat = `*WireFormat::getDefaultWireFormat()`
	)

Send the Interest through the transport, read the entire response and call onData(interest, data).

Parameters

interest	A reference to the Interest. This copies the Interest.
onData	A function object to call when a matching data packet is received. This copies the function object, so you may need to use func_lib::ref() as appropriate.
onTimeout	A function object to call if the interest times out. If onTimeout is an empty OnTimeout(), this does not use it. This copies the function object, so you may need to use func_lib::ref() as appropriate.
wireFormat	A WireFormat object used to encode the message. If omitted, use WireFormat getDefaultWireFormat().

Returns: The pending interest ID which can be used with removePendingInterest.

Exceptions

runtime_error If the encoded interest size exceeds getMaxNdnPacketSize().

uint64_t ndn::Face::expressInterest	(	const Name &	name,
		const Interest *	interestTemplate,
		const OnData &	onData,
		const OnTimeout &	onTimeout = `OnTimeout()`,
		WireFormat &	wireFormat = `*WireFormat::getDefaultWireFormat()`
	)

Encode name as an Interest.

If interestTemplate is not 0, use its interest selectors. Send the interest through the transport, read the entire response and call onData(interest, data).

Parameters

name	A reference to a Name for the interest. This copies the Name.
interestTemplate	if not 0, copy interest selectors from the template. This does not keep a pointer to the Interest object.
onData	A function object to call when a matching data packet is received. This copies the function object, so you may need to use func_lib::ref() as appropriate.
onTimeout	A function object to call if the interest times out. If onTimeout is an empty OnTimeout(), this does not use it. This copies the function object, so you may need to use func_lib::ref() as appropriate.
wireFormat	A WireFormat object used to encode the message. If omitted, use WireFormat getDefaultWireFormat().

Returns: The pending interest ID which can be used with removePendingInterest.

Exceptions

runtime_error If the encoded interest size exceeds getMaxNdnPacketSize().

uint64_t ndn::Face::expressInterest	(	const Name &	name,
		const OnData &	onData,
		const OnTimeout &	onTimeout = `OnTimeout()`,
		WireFormat &	wireFormat = `*WireFormat::getDefaultWireFormat()`
	)

inline

Encode name as an Interest, using a default interest lifetime.

Send the interest through the transport, read the entire response and call onData(interest, data).

Parameters

name	A reference to a Name for the interest. This copies the Name.
onData	A function object to call when a matching data packet is received. This copies the function object, so you may need to use func_lib::ref() as appropriate.
onTimeout	A function object to call if the interest times out. If onTimeout is an empty OnTimeout(), this does not use it. This copies the function object, so you may need to use func_lib::ref() as appropriate.
wireFormat	A WireFormat object used to encode the message. If omitted, use WireFormat getDefaultWireFormat().

Returns: The pending interest ID which can be used with removePendingInterest.

Exceptions

runtime_error If the encoded interest size exceeds getMaxNdnPacketSize().

static size_t ndn::Face::getMaxNdnPacketSize ( )

inlinestatic

Get the practical limit of the size of a network-layer packet.

If a packet is larger than this, the library or application MAY drop it. This is a static inline method wrapping a const, so you can to use as a constant, e.g.: uint8_t buffer[Face::getMaxNdnPacketSize()].

Returns: The maximum NDN packet size.

bool ndn::Face::isLocal ( )

Check if the face is local based on the current connection through the Transport; some Transport may cause network I/O (e.g.

an IP host name lookup).

Returns: True if the face is local, false if not.

Note: This is an experimental feature. This API may change in the future.

void ndn::Face::makeCommandInterest	(	Interest &	interest,
		WireFormat &	wireFormat = `*WireFormat::getDefaultWireFormat()`
	)

Append a timestamp component and a random value component to interest's name.

Then use the keyChain and certificateName from setCommandSigningInfo to sign the interest. If the interest lifetime is not set, this sets it.

Parameters

interest	The interest whose name is appended with components.
wireFormat	A WireFormat object used to encode the SignatureInfo and to encode the interest name for signing. If omitted, use WireFormat getDefaultWireFormat().

Note: This method is an experimental feature. See the API docs for more detail at http://named-data.net/doc/ndn-ccl-api/face.html#face-makecommandinterest-method .

void ndn::Face::processEvents ( )

Process any packets to receive and call callbacks such as onData, onInterest or onTimeout.

This returns immediately if there is no data to receive. This blocks while calling the callbacks. You should repeatedly call this from an event loop, with calls to sleep as needed so that the loop doesn’t use 100% of the CPU. Since processEvents modifies the pending interest table, your application should make sure that it calls processEvents in the same thread as expressInterest (which also modifies the pending interest table).

Exceptions

This	may throw an exception for reading data or in the callback for processing the data. If you call this from an main event loop, you may want to catch and log/disregard all exceptions.

void ndn::Face::putData	(	const Data &	data,
		WireFormat &	wireFormat = `*WireFormat::getDefaultWireFormat()`
	)

The OnInterestCallback calls this to put a Data packet which satisfies an Interest.

Parameters

data	The Data packet which satisfies the interest.
wireFormat	(optional) A WireFormat object used to encode the Data packet. If omitted, use WireFormat getDefaultWireFormat().

Exceptions

runtime_error If the encoded Data packet size exceeds getMaxNdnPacketSize().

uint64_t ndn::Face::registerPrefix	(	const Name &	prefix,
		const OnInterestCallback &	onInterest,
		const OnRegisterFailed &	onRegisterFailed,
		const ForwardingFlags &	flags = `ForwardingFlags()`,
		WireFormat &	wireFormat = `*WireFormat::getDefaultWireFormat()`
	)

Register prefix with the connected NDN hub and call onInterest when a matching interest is received.

If you have not called setCommandSigningInfo, this assumes you are connecting to NDNx. If you have called setCommandSigningInfo, this first sends an NFD registration request, and if that times out then this sends an NDNx registration request. If you need to register a prefix with NFD, you must first call setCommandSigningInfo.

Parameters

prefix	A reference to a Name for the prefix to register. This copies the Name.
onInterest	(optional) If not null, this creates an interest filter from prefix so that when an Interest is received which matches the filter, this calls the function object onInterest(prefix, interest, face, interestFilterId, filter). This copies the function object, so you may need to use func_lib::ref() as appropriate. If onInterest is null, it is ignored and you must call setInterestFilter.
onRegisterFailed	A function object to call if failed to retrieve the connected hub’s ID or failed to register the prefix. This calls onRegisterFailed(prefix) where prefix is the prefix given to registerPrefix.
flags	The flags for finer control of which interests are forward to the application. If omitted, use the default flags defined by the default ForwardingFlags constructor.
wireFormat	A WireFormat object used to encode the message. If omitted, use WireFormat getDefaultWireFormat().

Returns: The registered prefix ID which can be used with removeRegisteredPrefix.

uint64_t ndn::Face::registerPrefix	(	const Name &	prefix,
		const OnInterest &	onInterest,
		const OnRegisterFailed &	onRegisterFailed,
		const ForwardingFlags &	flags = `ForwardingFlags()`,
		WireFormat &	wireFormat = `*WireFormat::getDefaultWireFormat()`
	)

Deprecated:: Use registerPrefix where onInterest is an OnInterestCallback (which is passed this Face for calling putData) instead of the deprecated OnInterest (which is passed a Transport object).

void ndn::Face::removePendingInterest ( uint64_t pendingInterestId )

Remove the pending interest entry with the pendingInterestId from the pending interest table.

This does not affect another pending interest with a different pendingInterestId, even if it has the same interest name. If there is no entry with the pendingInterestId, do nothing.

Parameters

pendingInterestId The ID returned from expressInterest.

void ndn::Face::removeRegisteredPrefix ( uint64_t registeredPrefixId )

Remove the registered prefix entry with the registeredPrefixId from the registered prefix table.

This does not affect another registered prefix with a different registeredPrefixId, even if it has the same prefix name. If an interest filter was automatically created by registerPrefix, also remove it. If there is no entry with the registeredPrefixId, do nothing.

Parameters

registeredPrefixId The ID returned from registerPrefix.

void ndn::Face::send ( const Blob & encoding )

inline

Send the encoded packet out through the face.

Parameters

encoding The blob with the the encoded packet to send.

Exceptions

runtime_error If the encoded Data packet size exceeds getMaxNdnPacketSize().

void ndn::Face::send	(	const uint8_t *	encoding,
		size_t	encodingLength
	)

Send the encoded packet out through the face.

Parameters

encoding	The array of bytes for the encoded packet to send.
encodingLength	The number of bytes in the encoding array.

Exceptions

runtime_error If the encoded Data packet size exceeds getMaxNdnPacketSize().

void ndn::Face::setCommandCertificateName ( const Name & certificateName )

inline

Set the certificate name used to sign command interest (e.g.

for registerPrefix), using the KeyChain that was set with setCommandSigningInfo.

Parameters

certificateName The certificate name for signing interest. This makes a copy of the Name.

void ndn::Face::setCommandSigningInfo	(	KeyChain &	keyChain,
		const Name &	certificateName
	)

inline

Set the KeyChain and certificate name used to sign command interests (e.g.

for registerPrefix).

Parameters

keyChain	The KeyChain object for signing interests, which must remain valid for the life of this Face. You must create the KeyChain object and pass it in. You can create a default KeyChain for your system with the default KeyChain constructor.
certificateName	The certificate name for signing interests. This makes a copy of the Name. You can get the default certificate name with keyChain.getDefaultCertificateName() .

uint64_t ndn::Face::setInterestFilter	(	const InterestFilter &	filter,
		const OnInterestCallback &	onInterest
	)

Add an entry to the local interest filter table to call the onInterest callback for a matching incoming Interest.

This method only modifies the library's local callback table and does not register the prefix with the forwarder. It will always succeed. To register a prefix with the forwarder, use registerPrefix.

Parameters

filter	The InterestFilter with a prefix and optional regex filter used to match the name of an incoming Interest. This makes a copy of filter.
onInterest	When an Interest is received which matches the filter, this calls onInterest(prefix, interest, face, interestFilterId, filter).

Returns: The interest filter ID which can be used with unsetInterestFilter.

uint64_t ndn::Face::setInterestFilter	(	const Name &	prefix,
		const OnInterestCallback &	onInterest
	)

Add an entry to the local interest filter table to call the onInterest callback for a matching incoming Interest.

This method only modifies the library's local callback table and does not register the prefix with the forwarder. It will always succeed. To register a prefix with the forwarder, use registerPrefix.

Parameters

prefix	The Name prefix used to match the name of an incoming Interest.
onInterest	This creates an interest filter from prefix so that when an Interest is received which matches the filter, this calls onInterest(prefix, interest, face, interestFilterId, filter).

Returns: The interest filter ID which can be used with unsetInterestFilter.

void ndn::Face::unsetInterestFilter ( uint64_t interestFilterId )

Remove the interest filter entry which has the interestFilterId from the interest filter table.

This does not affect another interest filter with a different interestFilterId, even if it has the same prefix name. If there is no entry with the interestFilterId, do nothing.

Parameters

interestFilterId The ID returned from setInterestFilter.

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

include/ndn-cpp/face.hpp
src/face.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation