ndn::Pit Class Reference

Pending Interest Table. More...

#include <ndn/pit.hpp>

Classes
struct	Stats
	PIT statistics. More...

Public Member Functions
Interest management
PitInsertResult	insert (const Interest &interest, FaceId incomingFace, PitEntry **outEntry=nullptr)
	Insert an Interest.
PitEntry *	find (const Name &name)
	Find an entry by Name.
const PitEntry *	find (const Name &name) const
	Find an entry by Name (const version)
void	remove (PitEntry *entry)
	Remove an entry.
void	remove (const Name &name)
	Remove an entry by Name.
Statistics
size_t	size () const
	Get the current number of entries.
size_t	capacity () const
	Get the maximum number of entries.
const Stats &	stats () const
	Get statistics.

Timeout handling
using	TimeoutCallback = std::function< void(const PitEntry &)>
	Timeout callback.
void	processTimeouts (TimeMs now, TimeoutCallback callback=nullptr)
	Process timed-out entries.

Detailed Description

Pending Interest Table.

One of the core components of the forwarder. Records received Interests and manages which Faces to forward Data to when the corresponding Data arrives.

Pit pit;
 
// Insert an Interest
PitEntry* entry;
auto result = pit.insert(interest, incomingFaceId, &entry);
if (result == PitInsertResult::New) {
    // New Interest -> forward
} else if (result == PitInsertResult::Aggregated) {
    // Existing Interest -> no forwarding needed
}
 
// On Data reception
if (auto* entry = pit.find(dataName)) {
    // Forward Data to registered Faces
    for (size_t i = 0; i < entry->faceCount(); i++) {
        sendData(entry->face(i), data);
    }
    pit.remove(entry);
}

Definition at line 137 of file pit.hpp.

Member Typedef Documentation

TimeoutCallback

using ndn::Pit::TimeoutCallback = std::function<void(const PitEntry&)>

Timeout callback.

Called when an entry times out.

Definition at line 193 of file pit.hpp.

Member Function Documentation

capacity()

size_t ndn::Pit::capacity ( ) const

inline

Get the maximum number of entries.

Returns

Maximum number of entries

Definition at line 220 of file pit.hpp.

References ndn::PIT_MAX_ENTRIES.

find() [1/2]

PitEntry * ndn::Pit::find

(

const Name &

name

)

Find an entry by Name.

Parameters

name	Name to search for

Returns

Pointer to the entry if found, nullptr otherwise

Definition at line 88 of file pit.cpp.

Referenced by ndn::Forwarder::putData(), and remove().

find() [2/2]

const PitEntry * ndn::Pit::find

(

const Name &

name

)

const

Find an entry by Name (const version)

Parameters

name	Name to search for

Returns

Const pointer to the entry if found, nullptr otherwise

Definition at line 97 of file pit.cpp.

insert()

PitInsertResult ndn::Pit::insert	(	const Interest &	interest,
		FaceId	incomingFace,
		PitEntry **	outEntry = nullptr
	)

Insert an Interest.

If an entry with the same Name exists, aggregation is performed. If the same nonce is detected, it is treated as a loop.

Parameters

interest	Interest to insert
incomingFace	ID of the Face that received the Interest
outEntry	Stores a pointer to the created/updated entry (optional)

Returns

Insertion result

Definition at line 40 of file pit.cpp.

References ndn::PitEntry::addFace(), ndn::Pit::Stats::aggregations, ndn::currentTimeMs(), ndn::Pit::Stats::duplicates, ndn::Pit::Stats::insertions, ndn::Interest::lifetime(), ndn::Interest::name(), and ndn::Interest::nonce().

Referenced by ndn::Forwarder::expressInterest().

processTimeouts()

void ndn::Pit::processTimeouts	(	TimeMs	now,
		TimeoutCallback	callback = nullptr
	)

Process timed-out entries.

Removes entries that have expired beyond the current time and invokes the callback.

Parameters

now	Current time (milliseconds)
callback	Timeout callback (optional)

Definition at line 121 of file pit.cpp.

References ndn::Pit::Stats::timeouts.

Referenced by ndn::Forwarder::processEvents().

remove() [1/2]

void ndn::Pit::remove

(

const Name &

name

)

Remove an entry by Name.

Parameters

name	Name of the entry to remove

Definition at line 114 of file pit.cpp.

References find(), and remove().

remove() [2/2]

void ndn::Pit::remove

(

PitEntry *

entry

)

Remove an entry.

Parameters

entry

Pointer to the entry to remove

Definition at line 106 of file pit.cpp.

Referenced by ndn::Forwarder::putData(), and remove().

size()

size_t ndn::Pit::size ( ) const

inline

Get the current number of entries.

Returns

Number of entries

Definition at line 214 of file pit.hpp.

stats()

const Stats & ndn::Pit::stats ( ) const

inline

Get statistics.

Returns

Const reference to statistics

Definition at line 236 of file pit.hpp.

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

• include/ndn/pit.hpp
• src/pit.cpp