ndn::ContentStore Class Reference

Content Store. More...

#include <ndn/cs.hpp>

Classes
struct	Stats
	CS statistics. More...

Public Member Functions
	ContentStore ()=default
	Default constructor.
	~ContentStore ()
	Destructor.
	ContentStore (const ContentStore &)=delete
ContentStore &	operator= (const ContentStore &)=delete
	ContentStore (ContentStore &&)=delete
ContentStore &	operator= (ContentStore &&)=delete
Error	init (size_t maxEntries=CS_DEFAULT_ENTRIES)
	Initialize the Content Store.
Data management
Error	insert (const Data &data, TimeMs now)
	Insert Data into the cache.
const CsEntry *	find (const Name &name, bool mustBeFresh=false, TimeMs now=0) const
	Search the cache by Name.
void	remove (const Name &name)
	Remove the entry with the specified Name.
void	evictStale (TimeMs now)
	Remove stale entries.
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.

Detailed Description

Content Store.

One of the core components of the forwarder. Caches received Data and can respond to subsequent Interests without forwarding to the network.

Uses an LRU (Least Recently Used) replacement policy.

ContentStore cs;
 
// Cache Data
Data data;
data.setName("/sensor/temperature");
data.setContent("25.5 C");
data.setFreshnessPeriod(10000);  // Valid for 10 seconds
cs.insert(data, currentTimeMs());
 
// Search cache for Data
if (auto* entry = cs.find(interestName, mustBeFresh, now)) {
    // Cache hit
    sendData(entry->data());
}

Definition at line 92 of file cs.hpp.

Constructor & Destructor Documentation

~ContentStore()

ndn::ContentStore::~ContentStore

(

)

Destructor.

Frees memory allocated on PSRAM.

Definition at line 26 of file cs.cpp.

Member Function Documentation

capacity()

size_t ndn::ContentStore::capacity ( ) const

inline

Get the maximum number of entries.

Returns

Maximum number of entries

Definition at line 181 of file cs.hpp.

evictStale()

void ndn::ContentStore::evictStale

(

TimeMs

now

)

Remove stale entries.

Removes all entries that have exceeded their staleTime.

Parameters

now	Current time (milliseconds)

Definition at line 144 of file cs.cpp.

References ndn::ContentStore::Stats::evictions.

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

find()

const CsEntry * ndn::ContentStore::find	(	const Name &	name,
		bool	mustBeFresh = false,
		TimeMs	now = 0
	)		const

Search the cache by Name.

Parameters

name	Name to search for
mustBeFresh	If true, only return fresh Data
now	Current time (used when mustBeFresh=true)

Returns

Pointer to the entry if found, nullptr otherwise

Definition at line 115 of file cs.cpp.

init()

Error ndn::ContentStore::init

(

size_t

maxEntries = CS_DEFAULT_ENTRIES

)

Initialize the Content Store.

Allocates the entry array on PSRAM. This function must be called exactly once.

Parameters

maxEntries

Maximum number of entries (default: CS_DEFAULT_ENTRIES)

Returns

Error::Success on success, Error::NoMemory on PSRAM allocation failure, Error::AlreadyExists if already initialized

Definition at line 33 of file cs.cpp.

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

insert()

Error ndn::ContentStore::insert	(	const Data &	data,
		TimeMs	now
	)

Insert Data into the cache.

Overwrites if an entry with the same Name exists. If the cache is full, the oldest entry is evicted using the LRU policy.

Parameters

data	Data to cache
now	Current time (milliseconds)

Returns

Error::Success on success

Definition at line 61 of file cs.cpp.

References ndn::ContentStore::Stats::evictions, ndn::Data::freshnessPeriod(), ndn::ContentStore::Stats::insertions, and ndn::Data::name().

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

remove()

void ndn::ContentStore::remove

(

const Name &

name

)

Remove the entry with the specified Name.

Parameters

name	Name of the entry to remove

Definition at line 133 of file cs.cpp.

size()

size_t ndn::ContentStore::size ( ) const

inline

Get the current number of entries.

Returns

Number of entries

Definition at line 175 of file cs.hpp.

stats()

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

inline

Get statistics.

Returns

Const reference to statistics

Definition at line 197 of file cs.hpp.

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

• include/ndn/cs.hpp
• src/cs.cpp