pit

README

ndn-dpdk/container/pit

This package implements the Pending Interest Table (PIT).

Structure

The PIT is part of the PIT-CS Composite Table (PCCT). The PCCT provides the underlying storage and lookup functions for the PIT.

The PIT token is actually the 48-bit token identifying a PCC entry. The PIT automatically adds and removes this token upon inserting and deleting PIT entries on a PCC entry. Since each PCC entry can contain up to two PIT entries (one for MustBeFresh=0 and one for MustBeFresh=1), the same token identifies both PIT entries.

PIT Entry

Each PIT entry can contain many PIT downstream records (PitDn type) and PIT upstream records (PitUp type). The PitEntry type directly stores a small number of PitDn and PitUp. If more downstream/upstream records are required, the PIT extends the PitEntry with additional DN and UP slots using a PitEntryExt allocated from the PCCT's mempool.

A PIT entry also contains:

• a representative Interest
• a timer
• several other fields aggregated from downstream and upstream records
• a "FIB reference" that allows efficient access to the associated FIB entry (PitEntry_FindFibEntry)

Documentation

Overview

Package pit implements the Pending Interest Table.

Index

• Variables
• type Counters
  • func (cnt Counters) String() string
• type DnRecord
  • func (dn DnRecord) Expiry() eal.TscTime
  • func (dn DnRecord) FaceID() iface.ID
  • func (dn DnRecord) Nonce() ndn.Nonce
  • func (dn DnRecord) PitToken() uint64
• type Entry
  • func EntryFromPtr(ptr unsafe.Pointer) *Entry
  • func (entry *Entry) DnRecords() (list []DnRecord)
  • func (entry *Entry) FibSeqNum() uint32
  • func (entry *Entry) InsertDnRecord(interest *ndni.Packet) *DnRecord
  • func (entry *Entry) PitToken() uint64
  • func (entry *Entry) Ptr() unsafe.Pointer
  • func (entry *Entry) UpRecords() (list []UpRecord)
• type FindResult
  • func (fr FindResult) CopyToCPitFindResult(ptr unsafe.Pointer)
  • func (fr FindResult) ListEntries() (entries []*Entry)
  • func (fr FindResult) NeedDataDigest() bool
• type Pit
  • func FromPcct(pcct *pcct.Pcct) *Pit
  • func (pit *Pit) Erase(entry *Entry)
  • func (pit *Pit) FindByData(data *ndni.Packet) FindResult
  • func (pit *Pit) FindByNack(nack *ndni.Packet) *Entry
  • func (pit *Pit) Insert(interest *ndni.Packet, fibEntry *fibreplica.Entry) (pitEntry *Entry, csEntry *cs.Entry)
  • func (pit *Pit) Len() int
  • func (pit *Pit) ReadCounters() (cnt Counters)
  • func (pit *Pit) TriggerTimeoutSched()
• type SuppressConfig
  • func (sc SuppressConfig) CopyToC(ptr unsafe.Pointer)
• type UpRecord
  • func (up UpRecord) FaceID() iface.ID

Variables

var GqlCountersType = graphql.NewObject(graphql.ObjectConfig{
	Name:   "PitCounters",
	Fields: graphql.BindFields(Counters{}),
})

GqlCountersType is the GraphQL type for Counters.

Types

type Counters

type Counters struct {
	NEntries  uint64 `json:"nEntries"`  // current number of entries
	NInsert   uint64 `json:"nInsert"`   // how many inserts created a new PIT entry
	NFound    uint64 `json:"nFound"`    // how many inserts found an existing PIT entry
	NCsMatch  uint64 `json:"nCsMatch"`  // how many inserts matched a CS entry
	NAllocErr uint64 `json:"nAllocErr"` // how many inserts failed due to allocation error
	NDataHit  uint64 `json:"nDataHit"`  // how many find-by-Data found PIT entry/entries
	NDataMiss uint64 `json:"nDataMiss"` // how many find-by-Data did not find PIT entry
	NNackHit  uint64 `json:"nNackHit"`  // how many find-by-Nack found PIT entry
	NNackMiss uint64 `json:"nNackMiss"` // how many find-by-Nack did not found PIT entry
	NExpired  uint64 `json:"nExpired"`  // how many entries expired
}

Counters contains PIT counters.

func (Counters) String

func (cnt Counters) String() string

type DnRecord

type DnRecord struct {
	// contains filtered or unexported fields
}

DnRecord represents a PIT downstream record.

func (DnRecord) Expiry

func (dn DnRecord) Expiry() eal.TscTime

Expiry returns a timestamp when this record expires.

func (DnRecord) FaceID

func (dn DnRecord) FaceID() iface.ID

FaceID returns the face ID.

func (DnRecord) Nonce

func (dn DnRecord) Nonce() ndn.Nonce

Nonce returns the last received Nonce.

func (DnRecord) PitToken

func (dn DnRecord) PitToken() uint64

PitToken returns the last received PIT token.

type Entry

type Entry C.PitEntry

Entry represents a PIT entry.

func EntryFromPtr

func EntryFromPtr(ptr unsafe.Pointer) *Entry

EntryFromPtr converts *C.PitEntry to Entry.

func (*Entry) DnRecords

func (entry *Entry) DnRecords() (list []DnRecord)

DnRecords returns downstream records.

func (*Entry) FibSeqNum

func (entry *Entry) FibSeqNum() uint32

FibSeqNum returns the FIB insertion sequence number recorded in this entry.

func (*Entry) InsertDnRecord

func (entry *Entry) InsertDnRecord(interest *ndni.Packet) *DnRecord

InsertDnRecord inserts new downstream record, or update existing downstream record.

func (*Entry) PitToken

func (entry *Entry) PitToken() uint64

PitToken returns the PIT token assigned to this entry.

func (*Entry) Ptr

func (entry *Entry) Ptr() unsafe.Pointer

Ptr returns *C.PitEntry pointer.

func (*Entry) UpRecords

func (entry *Entry) UpRecords() (list []UpRecord)

UpRecords returns upstream records.

type FindResult

type FindResult C.PitFindResult

FindResult represents the result of Pit.FindByData.

func (FindResult) CopyToCPitFindResult

func (fr FindResult) CopyToCPitFindResult(ptr unsafe.Pointer)

CopyToCPitFindResult copies this result to *C.PitFindResult.

func (FindResult) ListEntries

func (fr FindResult) ListEntries() (entries []*Entry)

ListEntries returns matched PIT entries.

func (FindResult) NeedDataDigest

func (fr FindResult) NeedDataDigest() bool

NeedDataDigest returns true if the result indicates that Data digest computation is needed.

type Pit

type Pit C.Pit

Pit represents a Pending Interest Table (PIT).

func FromPcct

func FromPcct(pcct *pcct.Pcct) *Pit

FromPcct converts Pcct to Pit.

func (*Pit) Erase

func (pit *Pit) Erase(entry *Entry)

Erase erases a PIT entry.

func (*Pit) FindByData

func (pit *Pit) FindByData(data *ndni.Packet) FindResult

FindByData searches for PIT entries matching a Data.

func (*Pit) FindByNack

func (pit *Pit) FindByNack(nack *ndni.Packet) *Entry

FindByNack searches for PIT entries matching a Nack.

func (*Pit) Insert

func (pit *Pit) Insert(interest *ndni.Packet, fibEntry *fibreplica.Entry) (pitEntry *Entry, csEntry *cs.Entry)

Insert attempts to insert a PIT entry for the given Interest. It returns either a new or existing PIT entry, or a CS entry that satisfies the Interest.

func (*Pit) Len

func (pit *Pit) Len() int

Len returns number of PIT entries.

func (*Pit) ReadCounters

func (pit *Pit) ReadCounters() (cnt Counters)

ReadCounters reads counters from this PIT.

func (*Pit) TriggerTimeoutSched

func (pit *Pit) TriggerTimeoutSched()

TriggerTimeoutSched triggers the internal timeout scheduler.

type SuppressConfig

type SuppressConfig struct {
	Min        nnduration.Nanoseconds `json:"min,omitempty"`
	Max        nnduration.Nanoseconds `json:"max,omitempty"`
	Multiplier float64                `json:"multiplier,omitempty"`
}

SuppressConfig contains PIT suppression configuration.

func (SuppressConfig) CopyToC

func (sc SuppressConfig) CopyToC(ptr unsafe.Pointer)

CopyToC copies this configuration to *C.PitSuppressConfig.

type UpRecord

type UpRecord struct {
	// contains filtered or unexported fields
}

UpRecord represents a PIT upstream record.

func (UpRecord) FaceID

func (up UpRecord) FaceID() iface.ID

FaceID returns the face ID.