A MetaInfo holds the meta info which is signed inside the Data packet. More...

#include <ndn-cxx/meta-info.hpp>

Classes
class	Error

Public Member Functions
	MetaInfo ()

	MetaInfo (const Block &block)
	Create from wire encoding. More...

MetaInfo &	addAppMetaInfo (const Block &block)
	Add an app-defined MetaInfo item. More...

const Block *	findAppMetaInfo (uint32_t tlvType) const
	Find a first app-defined MetaInfo item of type `tlvType`. More...

const std::list< Block > &	getAppMetaInfo () const
	Get all app-defined MetaInfo items. More...

const std::optional< name::Component > &	getFinalBlock () const noexcept
	Return the value of `FinalBlockId`. More...

time::milliseconds	getFreshnessPeriod () const noexcept
	Return the value of `FreshnessPeriod`. More...

uint32_t	getType () const noexcept
	Return the value of `ContentType`. More...

bool	removeAppMetaInfo (uint32_t tlvType)
	Remove a first app-defined MetaInfo item with type `tlvType`. More...

MetaInfo &	setAppMetaInfo (const std::list< Block > &info)
	Set app-defined MetaInfo items. More...

MetaInfo &	setFinalBlock (std::optional< name::Component > finalBlockId)
	Set the `FinalBlockId`. More...

MetaInfo &	setFreshnessPeriod (time::milliseconds freshnessPeriod)
	Set the `FreshnessPeriod`. More...

MetaInfo &	setType (uint32_t type)
	Set the `ContentType`. More...

void	wireDecode (const Block &wire)

const Block &	wireEncode () const

template<encoding::Tag TAG>
size_t	wireEncode (EncodingImpl< TAG > &encoder) const

Detailed Description

A MetaInfo holds the meta info which is signed inside the Data packet.

The class allows experimentation with application-defined meta-information elements. When using these application-defined elements, be aware that it may result in dropped packets (NFD and previous versions of ndn-cxx will gracefully accept such packets).

The following definition of the MetaInfo element is assumed in this implementation (compared to the NDN packet spec, the definition is extended to allow optional AppMetaInfo elements):

MetaInfo = META-INFO-TYPE TLV-LENGTH
             [ContentType]
             [FreshnessPeriod]
             [FinalBlockId]
             *AppMetaInfo

Note that AppMetaInfo elements are application-defined and must have a TLV-TYPE inside the range reserved for application use, i.e., [128, 252].

See also: https://docs.named-data.net/NDN-packet-spec/0.3/data.html#metainfo

Definition at line 61 of file meta-info.hpp.

Constructor & Destructor Documentation

◆ MetaInfo() [1/2]

ndn::MetaInfo::MetaInfo ( )

default

◆ MetaInfo() [2/2]

ndn::MetaInfo::MetaInfo ( const Block & block )

explicit

Create from wire encoding.

Definition at line 32 of file meta-info.cpp.

Member Function Documentation

◆ addAppMetaInfo()

MetaInfo & ndn::MetaInfo::addAppMetaInfo ( const Block & block )

Add an app-defined MetaInfo item.

Exceptions

Error if block has type not in the application range (https://docs.named-data.net/NDN-packet-spec/0.3/types.html)

Note: If MetaInfo is decoded from wire and setType, setFreshnessPeriod, or setFinalBlock is called before *AppMetaInfo, all app-defined blocks will be lost

Definition at line 93 of file meta-info.cpp.

◆ findAppMetaInfo()

const Block * ndn::MetaInfo::findAppMetaInfo ( uint32_t tlvType ) const

Find a first app-defined MetaInfo item of type tlvType.

Returns: NULL if an item is not found, otherwise const pointer to the item

Exceptions

Error if tlvType is not in the application range (https://docs.named-data.net/NDN-packet-spec/0.3/types.html)

Note: If MetaInfo is decoded from wire and setType, setFreshnessPeriod, or setFinalBlock is called before *AppMetaInfo, all app-defined blocks will be lost

Definition at line 117 of file meta-info.cpp.

◆ getAppMetaInfo()

const std::list< Block > & ndn::MetaInfo::getAppMetaInfo ( ) const

Get all app-defined MetaInfo items.

Note: If MetaInfo is decoded from wire and setType, setFreshnessPeriod, or setFinalBlock is called before *AppMetaInfo, all app-defined blocks will be lost

Definition at line 74 of file meta-info.cpp.

◆ getFinalBlock()

const std::optional<name::Component>& ndn::MetaInfo::getFinalBlock ( ) const

inlinenoexcept

Return the value of FinalBlockId.

Definition at line 128 of file meta-info.hpp.

◆ getFreshnessPeriod()

time::milliseconds ndn::MetaInfo::getFreshnessPeriod ( ) const

noexcept

Return the value of FreshnessPeriod.

If the FreshnessPeriod element is not present, returns DEFAULT_FRESHNESS_PERIOD. If the FreshnessPeriod value is not representable in the return type, it's clamped to the nearest representable value.

Definition at line 46 of file meta-info.cpp.

◆ getType()

uint32_t ndn::MetaInfo::getType ( ) const

inlinenoexcept

Return the value of ContentType.

If the ContentType element is not present, returns tlv::ContentType_Blob.

Definition at line 95 of file meta-info.hpp.

◆ removeAppMetaInfo()

bool ndn::MetaInfo::removeAppMetaInfo ( uint32_t tlvType )

Remove a first app-defined MetaInfo item with type tlvType.

Returns: true if an item was deleted

Note: If MetaInfo is decoded from wire and setType, setFreshnessPeriod, or setFinalBlock is called before *AppMetaInfo, all app-defined blocks will be lost

Definition at line 104 of file meta-info.cpp.

◆ setAppMetaInfo()

MetaInfo & ndn::MetaInfo::setAppMetaInfo ( const std::list< Block > & info )

Set app-defined MetaInfo items.

This method will replace all existing app-defined MetaInfo items, if they existed.

Exceptions

Error if some block in info has type not in the application range (https://docs.named-data.net/NDN-packet-spec/0.3/types.html)

Note: If MetaInfo is decoded from wire and setType, setFreshnessPeriod, or setFinalBlock is called before *AppMetaInfo, all app-defined blocks will be lost

Definition at line 80 of file meta-info.cpp.

◆ setFinalBlock()

MetaInfo & ndn::MetaInfo::setFinalBlock ( std::optional< name::Component > finalBlockId )

Set the FinalBlockId.

Definition at line 66 of file meta-info.cpp.

◆ setFreshnessPeriod()

MetaInfo & ndn::MetaInfo::setFreshnessPeriod ( time::milliseconds freshnessPeriod )

Set the FreshnessPeriod.

Exceptions

std::invalid_argument specified FreshnessPeriod is negative.

Definition at line 55 of file meta-info.cpp.

◆ setType()

MetaInfo & ndn::MetaInfo::setType ( uint32_t type )

Set the ContentType.

Parameters

type	A number defined in tlv::ContentTypeValue

Definition at line 38 of file meta-info.cpp.

◆ wireDecode()

void ndn::MetaInfo::wireDecode ( const Block & wire )

Definition at line 180 of file meta-info.cpp.

◆ wireEncode() [1/2]

const Block & ndn::MetaInfo::wireEncode ( ) const

Definition at line 164 of file meta-info.cpp.

◆ wireEncode() [2/2]

template<encoding::Tag TAG>

size_t ndn::MetaInfo::wireEncode ( EncodingImpl< TAG > & encoder ) const

Definition at line 126 of file meta-info.cpp.

ndn-cxx: NDN C++ library with eXperimental eXtensions 0.8.1-102-g0751bba8 documentation

Classes

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ MetaInfo() [1/2]

◆ MetaInfo() [2/2]

Member Function Documentation

◆ addAppMetaInfo()

◆ findAppMetaInfo()

◆ getAppMetaInfo()

◆ getFinalBlock()

◆ getFreshnessPeriod()

◆ getType()

◆ removeAppMetaInfo()

◆ setAppMetaInfo()

◆ setFinalBlock()

◆ setFreshnessPeriod()

◆ setType()

◆ wireDecode()

◆ wireEncode() [1/2]

◆ wireEncode() [2/2]