ndn::InMemoryStorage Class Referenceabstract

Represents in-memory storage. More...

#include <ndn-cxx/ims/in-memory-storage.hpp>

+ Inheritance diagram for ndn::InMemoryStorage:
+ Collaboration diagram for ndn::InMemoryStorage:

Classes

class  const_iterator
 Represents a self-defined const_iterator for the in-memory storage. More...
 
class  Error
 Represents an error might be thrown during reduce the current capacity of the in-memory storage through function setCapacity(size_t nMaxPackets). More...
 

Public Types

typedef boost::multi_index_container< InMemoryStorageEntry *, boost::multi_index::indexed_by< boost::multi_index::ordered_unique< boost::multi_index::tag< byFullName >, boost::multi_index::const_mem_fun< InMemoryStorageEntry, const Name &, &InMemoryStorageEntry::getFullName >, std::less< Name > > > > Cache
 

Public Member Functions

 InMemoryStorage (boost::asio::io_service &ioService, size_t limit=std::numeric_limits< size_t >::max())
 Create a InMemoryStorage with up to limit entries. More...
 
 InMemoryStorage (size_t limit=std::numeric_limits< size_t >::max())
 Create a InMemoryStorage with up to limit entries. More...
 
virtual ~InMemoryStorage ()
 
InMemoryStorage::const_iterator begin () const
 Returns begin iterator of the in-memory storage ordering by name with digest. More...
 
InMemoryStorage::const_iterator end () const
 Returns end iterator of the in-memory storage ordering by name with digest. More...
 
void erase (const Name &prefix, const bool isPrefix=true)
 Deletes in-memory storage entry by prefix by default. More...
 
shared_ptr< const Datafind (const Interest &interest)
 Finds the best match Data for an Interest. More...
 
shared_ptr< const Datafind (const Name &name)
 Finds the best match Data for a Name with or without implicit digest. More...
 
size_t getLimit () const
 
void insert (const Data &data, const time::milliseconds &mustBeFreshProcessingWindow=INFINITE_WINDOW)
 Inserts a Data packet. More...
 
size_t size () const
 

Static Public Attributes

static const time::milliseconds INFINITE_WINDOW
 

Protected Member Functions

virtual void afterAccess (InMemoryStorageEntry *entry)
 Update the entry when the entry is returned by the find() function according to derived class implemented replacement policy. More...
 
virtual void afterInsert (InMemoryStorageEntry *entry)
 Update the entry or other data structures after a entry is successfully inserted according to derived class implemented replacement policy. More...
 
virtual void beforeErase (InMemoryStorageEntry *entry)
 Update the entry or other data structures before a entry is successfully erased according to derived class implemented replacement policy. More...
 
void eraseImpl (const Name &name)
 Deletes in-memory storage entries by the Name with implicit digest. More...
 
virtual bool evictItem ()=0
 Removes one Data packet from in-memory storage based on derived class implemented replacement policy. More...
 
size_t getCapacity () const
 Returns current capacity of in-memory storage (in packets). More...
 
bool isFull () const
 Returns true if the in-memory storage uses up the current capacity, false otherwise. More...
 
void printCache (std::ostream &os) const
 Prints contents of the in-memory storage. More...
 
void setCapacity (size_t nMaxPackets)
 Sets current capacity of in-memory storage (in packets). More...
 

Detailed Description

Represents in-memory storage.

Definition at line 41 of file in-memory-storage.hpp.

Member Typedef Documentation

◆ Cache

typedef boost::multi_index_container< InMemoryStorageEntry*, boost::multi_index::indexed_by< boost::multi_index::ordered_unique< boost::multi_index::tag<byFullName>, boost::multi_index::const_mem_fun<InMemoryStorageEntry, const Name&, &InMemoryStorageEntry::getFullName>, std::less<Name> > > > ndn::InMemoryStorage::Cache

Definition at line 60 of file in-memory-storage.hpp.

Constructor & Destructor Documentation

◆ InMemoryStorage() [1/2]

ndn::InMemoryStorage::InMemoryStorage ( size_t  limit = std::numeric_limits<size_t>::max())
explicit

Create a InMemoryStorage with up to limit entries.

The InMemoryStorage created through this method will ignore MustBeFresh in interest processing

Definition at line 84 of file in-memory-storage.cpp.

◆ InMemoryStorage() [2/2]

ndn::InMemoryStorage::InMemoryStorage ( boost::asio::io_service &  ioService,
size_t  limit = std::numeric_limits<size_t>::max() 
)
explicit

Create a InMemoryStorage with up to limit entries.

The InMemoryStorage created through this method will handle MustBeFresh in interest processing

Definition at line 91 of file in-memory-storage.cpp.

◆ ~InMemoryStorage()

ndn::InMemoryStorage::~InMemoryStorage ( )
virtual
Note
Please make sure to implement it to free m_freeEntries and evict all items in the derived class for anybody who wishes to inherit this class.

Definition at line 114 of file in-memory-storage.cpp.

Member Function Documentation

◆ afterAccess()

void ndn::InMemoryStorage::afterAccess ( InMemoryStorageEntry entry)
protectedvirtual

Update the entry when the entry is returned by the find() function according to derived class implemented replacement policy.

Reimplemented in ndn::InMemoryStorageLru, and ndn::InMemoryStorageLfu.

Definition at line 380 of file in-memory-storage.cpp.

◆ afterInsert()

void ndn::InMemoryStorage::afterInsert ( InMemoryStorageEntry entry)
protectedvirtual

Update the entry or other data structures after a entry is successfully inserted according to derived class implemented replacement policy.

Reimplemented in ndn::InMemoryStorageLru, ndn::InMemoryStorageLfu, and ndn::InMemoryStorageFifo.

Definition at line 370 of file in-memory-storage.cpp.

◆ beforeErase()

void ndn::InMemoryStorage::beforeErase ( InMemoryStorageEntry entry)
protectedvirtual

Update the entry or other data structures before a entry is successfully erased according to derived class implemented replacement policy.

Reimplemented in ndn::InMemoryStorageLru, ndn::InMemoryStorageLfu, and ndn::InMemoryStorageFifo.

Definition at line 375 of file in-memory-storage.cpp.

◆ begin()

InMemoryStorage::const_iterator ndn::InMemoryStorage::begin ( ) const

Returns begin iterator of the in-memory storage ordering by name with digest.

Returns
const_iterator pointing to the beginning of the m_cache

Definition at line 356 of file in-memory-storage.cpp.

◆ end()

InMemoryStorage::const_iterator ndn::InMemoryStorage::end ( ) const

Returns end iterator of the in-memory storage ordering by name with digest.

Returns
const_iterator pointing to the end of the m_cache

Definition at line 363 of file in-memory-storage.cpp.

◆ erase()

void ndn::InMemoryStorage::erase ( const Name prefix,
const bool  isPrefix = true 
)

Deletes in-memory storage entry by prefix by default.

Parameters
prefixExact name of a prefix of the data to remove
isPrefixIf false, the function will only delete the entry completely matched with the prefix according to canonical ordering. For this case, user should substitute the prefix with full name.
Warning
Please do not use this function directly in any derived class to erase an entry from the cache, use eraseImpl() instead.
Note
It will invoke beforeErase(shared_ptr<InMemoryStorageEntry>).

Definition at line 321 of file in-memory-storage.cpp.

◆ eraseImpl()

void ndn::InMemoryStorage::eraseImpl ( const Name name)
protected

Deletes in-memory storage entries by the Name with implicit digest.

This is the function one should use to erase entry in the cache in derived class. It won't invoke beforeErase(shared_ptr<Entry>).

Definition at line 346 of file in-memory-storage.cpp.

◆ evictItem()

virtual bool ndn::InMemoryStorage::evictItem ( )
protectedpure virtual

Removes one Data packet from in-memory storage based on derived class implemented replacement policy.

Returns
whether a Data packet was removed
Warning
Please do not use this function directly in any derived class to erase an entry from the cache, use eraseImpl() instead.

Implemented in ndn::InMemoryStoragePersistent, ndn::InMemoryStorageLru, ndn::InMemoryStorageLfu, and ndn::InMemoryStorageFifo.

◆ find() [1/2]

shared_ptr< const Data > ndn::InMemoryStorage::find ( const Interest interest)

Finds the best match Data for an Interest.

Note
It will invoke afterAccess(shared_ptr<InMemoryStorageEntry>). As currently it is impossible to determine whether a Name contains implicit digest or not, therefore this find function is not able to locate a packet according to an interest( including implicit digest) whose name is not the full name of the data matching the implicit digest.
Returns
the best match, if any; otherwise a null shared_ptr

Definition at line 217 of file in-memory-storage.cpp.

◆ find() [2/2]

shared_ptr< const Data > ndn::InMemoryStorage::find ( const Name name)

Finds the best match Data for a Name with or without implicit digest.

If packets with the same name but different digests exist and the Name supplied is the one without implicit digest, a packet will be arbitrarily chosen to return.

Note
It will invoke afterAccess(shared_ptr<InMemoryStorageEntry>).
Returns
the one matched the Name; otherwise a null shared_ptr

Definition at line 198 of file in-memory-storage.cpp.

◆ getCapacity()

size_t ndn::InMemoryStorage::getCapacity ( ) const
inlineprotected

Returns current capacity of in-memory storage (in packets).

Returns
number of packets that can be stored in application cache

Definition at line 261 of file in-memory-storage.hpp.

◆ getLimit()

size_t ndn::InMemoryStorage::getLimit ( ) const
inline
Returns
Maximum number of packets that can be allowed to store in in-memory storage.

Definition at line 193 of file in-memory-storage.hpp.

◆ insert()

void ndn::InMemoryStorage::insert ( const Data data,
const time::milliseconds mustBeFreshProcessingWindow = INFINITE_WINDOW 
)

Inserts a Data packet.

Parameters
datathe packet to insert, must be signed and have wire encoding
mustBeFreshProcessingWindowBeyond this time period after the data is inserted, the data can only be used to answer interest without MustBeFresh selector.
Note
Packets are considered duplicate if the name with implicit digest matches. The new Data packet with the identical name, but a different payload will be placed in the in-memory storage.
It will invoke afterInsert(shared_ptr<InMemoryStorageEntry>).

Definition at line 161 of file in-memory-storage.cpp.

◆ isFull()

bool ndn::InMemoryStorage::isFull ( ) const
inlineprotected

Returns true if the in-memory storage uses up the current capacity, false otherwise.

Definition at line 269 of file in-memory-storage.hpp.

◆ printCache()

void ndn::InMemoryStorage::printCache ( std::ostream &  os) const
protected

Prints contents of the in-memory storage.

Definition at line 385 of file in-memory-storage.cpp.

◆ setCapacity()

void ndn::InMemoryStorage::setCapacity ( size_t  nMaxPackets)
protected

Sets current capacity of in-memory storage (in packets).

Definition at line 131 of file in-memory-storage.cpp.

◆ size()

size_t ndn::InMemoryStorage::size ( ) const
inline
Returns
Number of packets stored in in-memory storage.

Definition at line 201 of file in-memory-storage.hpp.

Member Data Documentation

◆ INFINITE_WINDOW

const time::milliseconds ndn::InMemoryStorage::INFINITE_WINDOW
static

Definition at line 328 of file in-memory-storage.hpp.