represents a CS replacement policy More...

#include <daemon/table/cs-policy.hpp>

Inheritance diagram for nfd::cs::Policy:

Collaboration diagram for nfd::cs::Policy:

Public Types
using	EntryRef = Table::const_iterator
	a reference to an CS entry More...

Public Member Functions
	Policy (const std::string &policyName)

virtual	~Policy ()=default

void	afterInsert (EntryRef i)
	invoked by CS after a new entry is inserted More...

void	afterRefresh (EntryRef i)
	invoked by CS after an existing entry is refreshed by same Data More...

void	beforeErase (EntryRef i)
	invoked by CS before an entry is erased due to management command More...

void	beforeUse (EntryRef i)
	invoked by CS before an entry is used to match a lookup More...

Cs *	getCs () const
	gets cs More...

size_t	getLimit () const
	gets hard limit (in number of entries) More...

const std::string &	getName () const

void	setCs (Cs *cs)
	sets cs More...

void	setLimit (size_t nMaxEntries)
	sets hard limit (in number of entries) More...

Static Public Member Functions
static unique_ptr< Policy >	create (const std::string &policyName)

static std::set< std::string >	getPolicyNames ()

template<typename P >
static void	registerPolicy (const std::string &policyName=P::POLICY_NAME)

Public Attributes
signal::Signal< Policy, EntryRef >	beforeEvict
	emits when an entry is being evicted More...

Protected Member Functions
virtual void	doAfterInsert (EntryRef i)=0
	invoked after a new entry is created in CS More...

virtual void	doAfterRefresh (EntryRef i)=0
	invoked after an existing entry is refreshed by same Data More...

virtual void	doBeforeErase (EntryRef i)=0
	invoked before an entry is erased due to management command More...

virtual void	doBeforeUse (EntryRef i)=0
	invoked before an entry is used to match a lookup More...

virtual void	evictEntries ()=0
	evicts zero or more entries More...

Detailed Description

represents a CS replacement policy

Definition at line 38 of file cs-policy.hpp.

Member Typedef Documentation

◆ EntryRef

using nfd::cs::Policy::EntryRef = Table::const_iterator

a reference to an CS entry

Note: operator< of EntryRef compares the Data name enclosed in the Entry.

Definition at line 111 of file cs-policy.hpp.

Constructor & Destructor Documentation

◆ Policy()

nfd::cs::Policy::Policy ( const std::string & policyName )

explicit

Definition at line 62 of file cs-policy.cpp.

◆ ~Policy()

virtual nfd::cs::Policy::~Policy ( )

virtualdefault

Member Function Documentation

◆ afterInsert()

void nfd::cs::Policy::afterInsert ( EntryRef i )

invoked by CS after a new entry is inserted

Postcondition: cs.size() <= getLimit()

The policy may evict entries if necessary. During this process, i might be evicted.

Definition at line 76 of file cs-policy.cpp.

◆ afterRefresh()

void nfd::cs::Policy::afterRefresh ( EntryRef i )

invoked by CS after an existing entry is refreshed by same Data

The policy may witness this refresh to make better eviction decisions in the future.

Definition at line 83 of file cs-policy.cpp.

◆ beforeErase()

void nfd::cs::Policy::beforeErase ( EntryRef i )

invoked by CS before an entry is erased due to management command

Warning: CS must not invoke this method if an entry is erased due to eviction.

Definition at line 90 of file cs-policy.cpp.

◆ beforeUse()

void nfd::cs::Policy::beforeUse ( EntryRef i )

invoked by CS before an entry is used to match a lookup

The policy may witness this usage to make better eviction decisions in the future.

Definition at line 97 of file cs-policy.cpp.

◆ create()

unique_ptr< Policy > nfd::cs::Policy::create ( const std::string & policyName )

static

Returns: a cs::Policy identified by policyName, or nullptr if policyName is unknown

Definition at line 46 of file cs-policy.cpp.

◆ doAfterInsert()

virtual void nfd::cs::Policy::doAfterInsert ( EntryRef i )

protectedpure virtual

invoked after a new entry is created in CS

When overridden in a subclass, a policy implementation should decide whether to accept i. If i is accepted, it should be inserted into a cleanup index. Otherwise, beforeEvict signal should be emitted with i to inform CS to erase the entry. A policy implementation may decide to evict other entries by emitting beforeEvict signal, in order to keep CS size under limit.

◆ doAfterRefresh()

virtual void nfd::cs::Policy::doAfterRefresh ( EntryRef i )

protectedpure virtual

invoked after an existing entry is refreshed by same Data

When overridden in a subclass, a policy implementation may witness this operation and adjust its cleanup index.

◆ doBeforeErase()

virtual void nfd::cs::Policy::doBeforeErase ( EntryRef i )

protectedpure virtual

invoked before an entry is erased due to management command

Note: This will not be invoked for an entry being evicted by policy.

When overridden in a subclass, a policy implementation should erase i from its cleanup index without emitted afterErase signal.

◆ doBeforeUse()

virtual void nfd::cs::Policy::doBeforeUse ( EntryRef i )

protectedpure virtual

invoked before an entry is used to match a lookup

When overridden in a subclass, a policy implementation may witness this operation and adjust its cleanup index.

◆ evictEntries()

virtual void nfd::cs::Policy::evictEntries ( )

protectedpure virtual

evicts zero or more entries

Postcondition: CS size does not exceed hard limit

◆ getCs()

Cs* nfd::cs::Policy::getCs ( ) const

inline

gets cs

Definition at line 77 of file cs-policy.hpp.

◆ getLimit()

size_t nfd::cs::Policy::getLimit ( ) const

inline

gets hard limit (in number of entries)

Definition at line 93 of file cs-policy.hpp.

◆ getName()

const std::string& nfd::cs::Policy::getName ( ) const

inline

Definition at line 69 of file cs-policy.hpp.

◆ getPolicyNames()

std::set< std::string > nfd::cs::Policy::getPolicyNames ( )

static

Returns: a list of available policy names

Definition at line 54 of file cs-policy.cpp.

◆ registerPolicy()

template<typename P >

static void nfd::cs::Policy::registerPolicy ( const std::string & policyName = P::POLICY_NAME )

inlinestatic

Definition at line 43 of file cs-policy.hpp.

◆ setCs()

void nfd::cs::Policy::setCs ( Cs * cs )

inline

sets cs

Definition at line 85 of file cs-policy.hpp.

◆ setLimit()

void nfd::cs::Policy::setLimit ( size_t nMaxEntries )

sets hard limit (in number of entries)

Postcondition: getLimit() == nMaxEntries; cs.size() <= getLimit()

The policy may evict entries if necessary.

Definition at line 68 of file cs-policy.cpp.

Member Data Documentation

◆ beforeEvict

signal::Signal<Policy, EntryRef> nfd::cs::Policy::beforeEvict

emits when an entry is being evicted

A policy implementation should emit this signal to cause CS to erase an entry from its index. CS should connect to this signal and erase the entry upon signal emission.

Definition at line 118 of file cs-policy.hpp.

NFD: Named Data Networking Forwarding Daemon 0.7.1 documentation

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Protected Member Functions

Detailed Description

Member Typedef Documentation

◆ EntryRef

Constructor & Destructor Documentation

◆ Policy()

◆ ~Policy()

Member Function Documentation

◆ afterInsert()

◆ afterRefresh()

◆ beforeErase()

◆ beforeUse()

◆ create()

◆ doAfterInsert()

◆ doAfterRefresh()

◆ doBeforeErase()

◆ doBeforeUse()

◆ evictEntries()

◆ getCs()

◆ getLimit()

◆ getName()

◆ getPolicyNames()

◆ registerPolicy()

◆ setCs()

◆ setLimit()

Member Data Documentation

◆ beforeEvict