ndn::Link Class Reference

Represents a LinkObject TLV element. More...

#include <ndn-cxx/link.hpp>

+ Inheritance diagram for ndn::Link:
+ Collaboration diagram for ndn::Link:

Classes

class  Error
 

Public Member Functions

 Link ()
 Create an empty Link object. More...
 
 Link (const Block &wire)
 Decode a Link object from a Block. More...
 
 Link (const Name &name, std::initializer_list< Name > delegations={})
 Create a Link object with the given name and delegations. More...
 
bool addDelegation (const Name &name)
 Append a delegation at the end. More...
 
InputBuffers extractSignedRanges () const
 Extract ranges of Data covered by the signature. More...
 
uint64_t getCongestionMark () const
 Get the value of the CongestionMark tag. More...
 
const BlockgetContent () const noexcept
 Get the Content element. More...
 
uint32_t getContentType () const noexcept
 Return the value of ContentType. More...
 
span< const NamegetDelegationList () const
 Get the delegations. 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...
 
const NamegetFullName () const
 Get the full name (including implicit digest). More...
 
std::optional< KeyLocatorgetKeyLocator () const noexcept
 Get the KeyLocator element. More...
 
const MetaInfogetMetaInfo () const noexcept
 Get the MetaInfo element. More...
 
const NamegetName () const noexcept
 Get the Data name. More...
 
const SignatureInfogetSignatureInfo () const noexcept
 Get the SignatureInfo element. More...
 
int32_t getSignatureType () const noexcept
 Get the SignatureType. More...
 
const BlockgetSignatureValue () const noexcept
 Get the SignatureValue element. More...
 
template<typename T >
std::shared_ptr< T > getTag () const
 Get a tag item. More...
 
bool hasContent () const noexcept
 Return whether this Data has a Content element. More...
 
bool hasWire () const noexcept
 Check if this instance has cached wire encoding. More...
 
bool removeDelegation (const Name &name)
 Remove a delegation whose name is name. More...
 
template<typename T >
void removeTag () const
 Remove a tag item. More...
 
void setCongestionMark (uint64_t mark)
 Set the CongestionMark tag to the specified value. More...
 
DatasetContent (const Block &block)
 Set Content from a Block. More...
 
DatasetContent (ConstBufferPtr value)
 Set Content from a shared buffer. More...
 
DatasetContent (span< const uint8_t > value)
 Set Content by copying from a contiguous sequence of bytes. More...
 
DatasetContent (std::nullptr_t)=delete
 
DatasetContent (std::string_view value)
 Set Content by copying from a string. More...
 
DatasetContentType (uint32_t type)
 Set the ContentType. More...
 
void setDelegationList (std::vector< Name > delegations)
 Set the delegations. More...
 
DatasetFinalBlock (std::optional< name::Component > finalBlockId)
 Set the FinalBlockId. More...
 
DatasetFreshnessPeriod (time::milliseconds freshnessPeriod)
 Set the FreshnessPeriod. More...
 
DatasetMetaInfo (const MetaInfo &metaInfo)
 Set the MetaInfo element. More...
 
DatasetName (const Name &name)
 Set the Data name. More...
 
DatasetSignatureInfo (const SignatureInfo &info)
 Set the SignatureInfo element. More...
 
DatasetSignatureValue (ConstBufferPtr value)
 Set SignatureValue from a shared buffer. More...
 
DatasetSignatureValue (span< const uint8_t > value)
 Set SignatureValue by copying from a contiguous sequence of bytes. More...
 
DatasetSignatureValue (std::nullptr_t)=delete
 
template<typename T >
void setTag (std::shared_ptr< T > tag) const
 Set (add or replace) a tag item. More...
 
DataunsetContent ()
 Remove the Content element. More...
 
void wireDecode (const Block &wire)
 Decode from the wire format. More...
 
const BlockwireEncode () const
 Encode into a Block. More...
 
const BlockwireEncode (EncodingBuffer &encoder, span< const uint8_t > signature) const
 Finalize Data packet encoding with the specified signature. More...
 
template<encoding::Tag TAG>
size_t wireEncode (EncodingImpl< TAG > &encoder, bool wantUnsignedPortionOnly=false) const
 Prepend wire encoding to encoder. More...
 

Protected Member Functions

void resetWire ()
 Clear wire encoding and cached FullName. More...
 

Detailed Description

Represents a LinkObject TLV element.

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

Definition at line 35 of file link.hpp.

Constructor & Destructor Documentation

◆ Link() [1/3]

ndn::Link::Link ( )
default

Create an empty Link object.

Note that in certain contexts that use Link::shared_from_this(), Link must be created using make_shared:

shared_ptr<Link> linkObject = make_shared<Link>();

◆ Link() [2/3]

ndn::Link::Link ( const Block wire)
explicit

Decode a Link object from a Block.

Parameters
wirea TLV block

Note that in certain contexts that use Link::shared_from_this(), Link must be created using make_shared:

shared_ptr<Link> linkObject = make_shared<Link>(block);

Definition at line 30 of file link.cpp.

◆ Link() [3/3]

ndn::Link::Link ( const Name name,
std::initializer_list< Name delegations = {} 
)
explicit

Create a Link object with the given name and delegations.

Parameters
nameA reference to the name of the redirected namespace
delegationsDelegations in payload

Note that in certain contexts that use Link::shared_from_this(), Link must be created using make_shared:

shared_ptr<Link> link = make_shared<Link>(name, delegations);

Definition at line 35 of file link.cpp.

Member Function Documentation

◆ addDelegation()

bool ndn::Link::addDelegation ( const Name name)

Append a delegation at the end.

Parameters
nameDelegation name
Returns
true if delegation is added, false if same name already exists

Definition at line 81 of file link.cpp.

◆ extractSignedRanges()

InputBuffers ndn::Data::extractSignedRanges ( ) const
inherited

Extract ranges of Data covered by the signature.

Exceptions
ErrorData cannot be encoded or is missing ranges necessary for signing
Warning
The returned pointers will be invalidated if wireDecode() or wireEncode() are called.

Definition at line 323 of file data.cpp.

◆ getCongestionMark()

uint64_t ndn::PacketBase::getCongestionMark ( ) const
inherited

Get the value of the CongestionMark tag.

Definition at line 28 of file packet-base.cpp.

◆ getContent()

const Block& ndn::Data::getContent ( ) const
inlinenoexceptinherited

Get the Content element.

If the element is not present (hasContent() == false), an invalid Block will be returned.

The value of the returned Content Block (if valid) can be accessed through

See also
hasContent()
Block::value_bytes(), Block::blockFromValue(), Block::parse()

Definition at line 188 of file data.hpp.

◆ getContentType()

uint32_t ndn::Data::getContentType ( ) const
inlinenoexceptinherited

Return the value of ContentType.

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

Definition at line 312 of file data.hpp.

◆ getDelegationList()

span<const Name> ndn::Link::getDelegationList ( ) const
inline

Get the delegations.

Definition at line 85 of file link.hpp.

◆ getFinalBlock()

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

Return the value of FinalBlockId.

Definition at line 342 of file data.hpp.

◆ getFreshnessPeriod()

time::milliseconds ndn::Data::getFreshnessPeriod ( ) const
inlinenoexceptinherited

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 327 of file data.hpp.

◆ getFullName()

const Name & ndn::Data::getFullName ( ) const
inherited

Get the full name (including implicit digest).

Precondition
hasWire() == true, i.e., wireEncode() must have been called.
Exceptions
ErrorData has no wire encoding

Definition at line 200 of file data.cpp.

◆ getKeyLocator()

std::optional<KeyLocator> ndn::Data::getKeyLocator ( ) const
inlinenoexceptinherited

Get the KeyLocator element.

Definition at line 367 of file data.hpp.

◆ getMetaInfo()

const MetaInfo& ndn::Data::getMetaInfo ( ) const
inlinenoexceptinherited

Get the MetaInfo element.

Definition at line 153 of file data.hpp.

◆ getName()

const Name& ndn::Data::getName ( ) const
inlinenoexceptinherited

Get the Data name.

Definition at line 137 of file data.hpp.

◆ getSignatureInfo()

const SignatureInfo& ndn::Data::getSignatureInfo ( ) const
inlinenoexceptinherited

Get the SignatureInfo element.

Definition at line 243 of file data.hpp.

◆ getSignatureType()

int32_t ndn::Data::getSignatureType ( ) const
inlinenoexceptinherited

Get the SignatureType.

Returns
tlv::SignatureTypeValue, or -1 to indicate an invalid SignatureInfo.

Definition at line 358 of file data.hpp.

◆ getSignatureValue()

const Block& ndn::Data::getSignatureValue ( ) const
inlinenoexceptinherited

Get the SignatureValue element.

Definition at line 265 of file data.hpp.

◆ getTag()

template<typename T >
std::shared_ptr< T > ndn::TagHost::getTag
inherited

Get a tag item.

Template Parameters
Ttype of the tag, which must be a subclass of ndn::Tag
Return values
nullptrif no Tag of type T is stored

Definition at line 72 of file tag-host.hpp.

◆ hasContent()

bool ndn::Data::hasContent ( ) const
inlinenoexceptinherited

Return whether this Data has a Content element.

Definition at line 169 of file data.hpp.

◆ hasWire()

bool ndn::Data::hasWire ( ) const
inlinenoexceptinherited

Check if this instance has cached wire encoding.

Definition at line 119 of file data.hpp.

◆ removeDelegation()

bool ndn::Link::removeDelegation ( const Name name)

Remove a delegation whose name is name.

Parameters
nameDelegation name
Returns
true if delegation is removed, otherwise false

Definition at line 93 of file link.cpp.

◆ removeTag()

template<typename T >
void ndn::TagHost::removeTag
inherited

Remove a tag item.

Template Parameters
Ttype of the tag, which must be a subclass of ndn::Tag
Note
Tag can be removed even on a const tag host instance

Definition at line 98 of file tag-host.hpp.

◆ resetWire()

void ndn::Data::resetWire ( )
protectedinherited

Clear wire encoding and cached FullName.

Note
This does not clear the SignatureValue.

Definition at line 214 of file data.cpp.

◆ setCongestionMark()

void ndn::PacketBase::setCongestionMark ( uint64_t  mark)
inherited

Set the CongestionMark tag to the specified value.

Definition at line 41 of file packet-base.cpp.

◆ setContent() [1/5]

Data & ndn::Data::setContent ( const Block block)
inherited

Set Content from a Block.

Parameters
blockTLV element to be used as Content; must be valid
Returns
A reference to this Data, to allow chaining.

If the block's TLV-TYPE is tlv::Content, it will be used directly as this Data's Content element. Otherwise, the block will be nested into a Content element.

Definition at line 239 of file data.cpp.

◆ setContent() [2/5]

Data & ndn::Data::setContent ( ConstBufferPtr  value)
inherited

Set Content from a shared buffer.

Parameters
valuebuffer with the TLV-VALUE of the content; must not be null
Returns
A reference to this Data, to allow chaining.

Definition at line 273 of file data.cpp.

◆ setContent() [3/5]

Data & ndn::Data::setContent ( span< const uint8_t >  value)
inherited

Set Content by copying from a contiguous sequence of bytes.

Parameters
valuebuffer with the TLV-VALUE of the content
Returns
A reference to this Data, to allow chaining.

Definition at line 257 of file data.cpp.

◆ setContent() [4/5]

Data& ndn::Data::setContent ( std::nullptr_t  )
deleteinherited

◆ setContent() [5/5]

Data & ndn::Data::setContent ( std::string_view  value)
inherited

Set Content by copying from a string.

Parameters
valuestring with the TLV-VALUE of the content
Returns
A reference to this Data, to allow chaining.

Definition at line 265 of file data.cpp.

◆ setContentType()

Data & ndn::Data::setContentType ( uint32_t  type)
inherited

Set the ContentType.

Parameters
typeA number defined in tlv::ContentTypeValue

Definition at line 337 of file data.cpp.

◆ setDelegationList()

void ndn::Link::setDelegationList ( std::vector< Name delegations)

Set the delegations.

Note
This is more efficient than multiple addDelegation and removeDelegation invocations.

Definition at line 74 of file link.cpp.

◆ setFinalBlock()

Data & ndn::Data::setFinalBlock ( std::optional< name::Component finalBlockId)
inherited

Set the FinalBlockId.

Definition at line 357 of file data.cpp.

◆ setFreshnessPeriod()

Data & ndn::Data::setFreshnessPeriod ( time::milliseconds  freshnessPeriod)
inherited

Set the FreshnessPeriod.

Exceptions
std::invalid_argumentspecified FreshnessPeriod is negative.

Definition at line 347 of file data.cpp.

◆ setMetaInfo()

Data & ndn::Data::setMetaInfo ( const MetaInfo metaInfo)
inherited

Set the MetaInfo element.

Returns
A reference to this Data, to allow chaining.

Definition at line 231 of file data.cpp.

◆ setName()

Data & ndn::Data::setName ( const Name name)
inherited

Set the Data name.

Returns
A reference to this Data, to allow chaining.

Definition at line 221 of file data.cpp.

◆ setSignatureInfo()

Data & ndn::Data::setSignatureInfo ( const SignatureInfo info)
inherited

Set the SignatureInfo element.

This is a low-level function that should not normally be called directly by applications. Instead, provide a SignatureInfo to the SigningInfo object passed to KeyChain::sign().

Returns
A reference to this Data, to allow chaining.
Warning
SignatureInfo is overwritten when the packet is signed via KeyChain::sign().
See also
SigningInfo

Definition at line 295 of file data.cpp.

◆ setSignatureValue() [1/3]

Data & ndn::Data::setSignatureValue ( ConstBufferPtr  value)
inherited

Set SignatureValue from a shared buffer.

Parameters
valuebuffer containing the TLV-VALUE of the SignatureValue; must not be null
Returns
A reference to this Data, to allow chaining.

This is a low-level function that should not normally be called directly by applications. Instead, use KeyChain::sign() to sign the packet.

Warning
SignatureValue is overwritten when the packet is signed via KeyChain::sign().

Definition at line 311 of file data.cpp.

◆ setSignatureValue() [2/3]

Data & ndn::Data::setSignatureValue ( span< const uint8_t >  value)
inherited

Set SignatureValue by copying from a contiguous sequence of bytes.

Parameters
valuebuffer from which the TLV-VALUE of the SignatureValue will be copied
Returns
A reference to this Data, to allow chaining.

This is a low-level function that should not normally be called directly by applications. Instead, use KeyChain::sign() to sign the packet.

Warning
SignatureValue is overwritten when the packet is signed via KeyChain::sign().

Definition at line 303 of file data.cpp.

◆ setSignatureValue() [3/3]

Data& ndn::Data::setSignatureValue ( std::nullptr_t  )
deleteinherited

◆ setTag()

template<typename T >
void ndn::TagHost::setTag ( std::shared_ptr< T >  tag) const
inherited

Set (add or replace) a tag item.

Template Parameters
Ttype of the tag, which must be a subclass of ndn::Tag
Note
Tag can be set even on a const tag host instance

Definition at line 84 of file tag-host.hpp.

◆ unsetContent()

Data & ndn::Data::unsetContent ( )
inherited

Remove the Content element.

Returns
A reference to this Data, to allow chaining.
Postcondition
hasContent() == false

Definition at line 285 of file data.cpp.

◆ wireDecode()

void ndn::Link::wireDecode ( const Block wire)

Decode from the wire format.

Parameters
wirea TLV block

Definition at line 50 of file link.cpp.

◆ wireEncode() [1/3]

const Block & ndn::Data::wireEncode ( ) const
inherited

Encode into a Block.

Precondition
Data must be signed.

Definition at line 102 of file data.cpp.

◆ wireEncode() [2/3]

const Block & ndn::Data::wireEncode ( EncodingBuffer &  encoder,
span< const uint8_t >  signature 
) const
inherited

Finalize Data packet encoding with the specified signature.

Parameters
encoderEncodingBuffer containing Name, MetaInfo, Content, and SignatureInfo, but without SignatureValue and the outermost Type-Length of the Data element.
signatureRaw signature bytes, without TLV Type and Length; this will become the TLV-VALUE of the SignatureValue element added to the packet.

This method is intended to be used in concert with wireEncode(encoder, true), e.g.:

Data data;
...
EncodingBuffer encoder;
data.wireEncode(encoder, true);
...
auto signature = create_signature_over_signed_portion(encoder.data(), encoder.size());
data.wireEncode(encoder, signature);
Data(const Name &name=Name())
Construct an unsigned Data packet with given name and empty Content.
Definition: data.cpp:27

Definition at line 87 of file data.cpp.

◆ wireEncode() [3/3]

template<encoding::Tag TAG>
size_t ndn::Data::wireEncode ( EncodingImpl< TAG > &  encoder,
bool  wantUnsignedPortionOnly = false 
) const
inherited

Prepend wire encoding to encoder.

Parameters
encoderEncodingEstimator or EncodingBuffer instance.
wantUnsignedPortionOnlyIf true, prepend only Name, MetaInfo, Content, and SignatureInfo to encoder, but omit SignatureValue and the outermost TLV Type and Length of the Data element. This is intended to be used with wireEncode(EncodingBuffer&, span<const uint8_t>) const.
Exceptions
ErrorSignature is not present and wantUnsignedPortionOnly is false.

Definition at line 39 of file data.cpp.