NS-3 based Named Data Networking (NDN) simulator
ndnSIM 2.5: NDN, CCN, CCNx, content centric networks
API Documentation
nfd::DeadNonceList Class Reference

represents the Dead Nonce list More...

#include <dead-nonce-list.hpp>

Inheritance diagram for nfd::DeadNonceList:
Collaboration diagram for nfd::DeadNonceList:

Public Member Functions

 DeadNonceList (const time::nanoseconds &lifetime=DEFAULT_LIFETIME)
 constructs the Dead Nonce List More...
 ~DeadNonceList ()
bool has (const Name &name, uint32_t nonce) const
 determines if name+nonce exists More...
void add (const Name &name, uint32_t nonce)
 records name+nonce More...
size_t size () const
const time::nanoseconds & getLifetime () const

Static Public Attributes

static const time::nanoseconds DEFAULT_LIFETIME = 6_s
 default entry lifetime More...
static const time::nanoseconds MIN_LIFETIME = 1_ms
 minimum entry lifetime More...

Detailed Description

represents the Dead Nonce list

The Dead Nonce List is a global table that supplements PIT for loop detection. When a Nonce is erased (dead) from PIT entry, the Nonce and the Interest Name is added to Dead Nonce List, and kept for a duration in which most loops are expected to have occured.

To reduce memory usage, the Interest Name and Nonce are stored as a 64-bit hash. There could be false positives (non-looping Interest could be considered looping), but the probability is small, and the error is recoverable when consumer retransmits with a different Nonce.

To reduce memory usage, entries do not have associated timestamps. Instead, lifetime of entries is controlled by dynamically adjusting the capacity of the container. At fixed intervals, the MARK, an entry with a special value, is inserted into the container. The number of MARKs stored in the container reflects the lifetime of entries, because MARKs are inserted at fixed intervals.

Definition at line 54 of file dead-nonce-list.hpp.

Constructor & Destructor Documentation

◆ DeadNonceList()

nfd::DeadNonceList::DeadNonceList ( const time::nanoseconds &  lifetime = DEFAULT_LIFETIME)

constructs the Dead Nonce List

lifetimeduration of the expected lifetime of each nonce, must be no less than MIN_LIFETIME. This should be set to the duration in which most loops would have occured. A loop cannot be detected if delay of the cycle is greater than lifetime.
std::invalid_argumentif lifetime is less than MIN_LIFETIME

Definition at line 45 of file dead-nonce-list.cpp.

References MIN_LIFETIME, and nfd::scheduler::schedule().

◆ ~DeadNonceList()

nfd::DeadNonceList::~DeadNonceList ( )

Definition at line 65 of file dead-nonce-list.cpp.

References nfd::scheduler::cancel(), DEFAULT_LIFETIME, and MIN_LIFETIME.

Member Function Documentation

◆ has()

bool nfd::DeadNonceList::has ( const Name name,
uint32_t  nonce 
) const

determines if name+nonce exists

true if name+nonce exists

Definition at line 89 of file dead-nonce-list.cpp.

◆ add()

void nfd::DeadNonceList::add ( const Name name,
uint32_t  nonce 

records name+nonce

Definition at line 96 of file dead-nonce-list.cpp.

◆ size()

size_t nfd::DeadNonceList::size ( ) const
number of stored Nonces
The return value does not contain non-Nonce entries in the index, if any.

Definition at line 83 of file dead-nonce-list.cpp.

◆ getLifetime()

const time::nanoseconds & nfd::DeadNonceList::getLifetime ( ) const
expected lifetime

Definition at line 215 of file dead-nonce-list.hpp.

Member Data Documentation


const time::nanoseconds nfd::DeadNonceList::DEFAULT_LIFETIME = 6_s

default entry lifetime

Definition at line 136 of file dead-nonce-list.hpp.

Referenced by ~DeadNonceList().


const time::nanoseconds nfd::DeadNonceList::MIN_LIFETIME = 1_ms

minimum entry lifetime

Definition at line 139 of file dead-nonce-list.hpp.

Referenced by DeadNonceList(), and ~DeadNonceList().

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