data::LedgerCache Class Reference

Cache for an entire ledger. More...

#include <LedgerCache.hpp>

Inheritance diagram for data::LedgerCache:

Collaboration diagram for data::LedgerCache:

Classes
struct	CacheEntry
	An entry of the cache. More...

Public Types
using	CacheMap = std::map<ripple::uint256, CacheEntry>

Public Member Functions
void	update (std::vector< LedgerObject > const &objs, uint32_t seq, bool isBackground) override
	Update the cache with new ledger objects.
void	update (std::vector< etl::model::Object > const &objs, uint32_t seq) override
	Update the cache with new ledger objects.
std::optional< Blob >	get (ripple::uint256 const &key, uint32_t seq) const override
	Fetch a cached object by its key and sequence number.
std::optional< Blob >	getDeleted (ripple::uint256 const &key, uint32_t seq) const override
	Fetch a recently deleted object by its key and sequence number.
std::optional< LedgerObject >	getSuccessor (ripple::uint256 const &key, uint32_t seq) const override
	Gets a cached successor.
std::optional< LedgerObject >	getPredecessor (ripple::uint256 const &key, uint32_t seq) const override
	Gets a cached predcessor.
void	setDisabled () override
	Disables the cache.
bool	isDisabled () const override
void	setFull () override
	Sets the full flag to true.
uint32_t	latestLedgerSequence () const override
bool	isFull () const override
size_t	size () const override
float	getObjectHitRate () const override
float	getSuccessorHitRate () const override
void	waitUntilCacheContainsSeq (uint32_t seq) override
	Waits until the cache contains a specific sequence.
std::expected< void, std::string >	saveToFile (std::string const &path) const
	Save the cache to file.
std::expected< void, std::string >	loadFromFile (std::string const &path, uint32_t minLatestSequence) override
	Load the cache from file.
Public Member Functions inherited from data::LedgerCacheInterface
	LedgerCacheInterface (LedgerCacheInterface &&)=delete
	LedgerCacheInterface (LedgerCacheInterface const &)=delete
LedgerCacheInterface &	operator= (LedgerCacheInterface &&)=delete
LedgerCacheInterface &	operator= (LedgerCacheInterface const &)=delete

Detailed Description

Cache for an entire ledger.

Member Function Documentation

get()

std::optional< Blob > data::LedgerCache::get ( ripple::uint256 const & key, uint32_t seq ) const

overridevirtual

Fetch a cached object by its key and sequence number.

Parameters

key	The key to fetch for
seq	The sequence to fetch for

Returns

If found in cache, will return the cached Blob; otherwise nullopt is returned

Implements data::LedgerCacheInterface.

getDeleted()

std::optional< Blob > data::LedgerCache::getDeleted ( ripple::uint256 const & key, uint32_t seq ) const

overridevirtual

Fetch a recently deleted object by its key and sequence number.

Parameters

key	The key to fetch for
seq	The sequence to fetch for

Returns

If found in deleted cache, will return the cached Blob; otherwise nullopt is returned

Implements data::LedgerCacheInterface.

getObjectHitRate()

float data::LedgerCache::getObjectHitRate ( ) const

overridevirtual

Returns

A number representing the success rate of hitting an object in the cache versus missing it.

Implements data::LedgerCacheInterface.

getPredecessor()

std::optional< LedgerObject > data::LedgerCache::getPredecessor ( ripple::uint256 const & key, uint32_t seq ) const

overridevirtual

Gets a cached predcessor.

Note: This function always returns std::nullopt when isFull() returns false.

Parameters

key	The key to fetch for
seq	The sequence to fetch for

Returns

If found in cache, will return the cached predcessor; otherwise nullopt is returned

Implements data::LedgerCacheInterface.

getSuccessor()

std::optional< LedgerObject > data::LedgerCache::getSuccessor ( ripple::uint256 const & key, uint32_t seq ) const

overridevirtual

Gets a cached successor.

Note: This function always returns std::nullopt when isFull() returns false.

Parameters

key	The key to fetch for
seq	The sequence to fetch for

Returns

If found in cache, will return the cached successor; otherwise nullopt is returned

Implements data::LedgerCacheInterface.

getSuccessorHitRate()

float data::LedgerCache::getSuccessorHitRate ( ) const

overridevirtual

Returns

A number representing the success rate of hitting a successor in the cache versus missing it.

Implements data::LedgerCacheInterface.

isDisabled()

bool data::LedgerCache::isDisabled ( ) const

overridevirtual

Returns

true if the cache is disabled; false otherwise

Implements data::LedgerCacheInterface.

isFull()

bool data::LedgerCache::isFull ( ) const

overridevirtual

Returns

true if the cache has all data for the most recent ledger; false otherwise

Implements data::LedgerCacheInterface.

latestLedgerSequence()

uint32_t data::LedgerCache::latestLedgerSequence ( ) const

overridevirtual

Returns

The latest ledger sequence for which cache is available.

Implements data::LedgerCacheInterface.

loadFromFile()

std::expected< void, std::string > data::LedgerCache::loadFromFile ( std::string const & path, uint32_t minLatestSequence )

overridevirtual

Load the cache from file.

Note

This operation takes about 7 seconds and it keeps mtx_ exclusively locked

Parameters

path	The file path to load data from
minLatestSequence	The minimum allowed value of the latestLedgerSequence in cache file

Returns

An error as a string if any

Implements data::LedgerCacheInterface.

saveToFile()

std::expected< void, std::string > data::LedgerCache::saveToFile

(

std::string const &

path

)

const

Save the cache to file.

Note

This operation takes about 7 seconds and it keeps mtx_ exclusively locked

Parameters

path	The file path to save the cache to

Returns

An error as a string if any

setDisabled()

void data::LedgerCache::setDisabled ( )

overridevirtual

Disables the cache.

Implements data::LedgerCacheInterface.

setFull()

void data::LedgerCache::setFull ( )

overridevirtual

Sets the full flag to true.

This is used when cache loaded in its entirety at startup of the application. This can be either loaded from DB, populated together with initial ledger download (on first run) or downloaded from a peer node (specified in config).

Implements data::LedgerCacheInterface.

size()

size_t data::LedgerCache::size ( ) const

overridevirtual

Returns

The total size of the cache.

Implements data::LedgerCacheInterface.

update() [1/2]

void data::LedgerCache::update ( std::vector< etl::model::Object > const & objs, uint32_t seq )

overridevirtual

Update the cache with new ledger objects.

Parameters

objs	The ledger objects to update cache with
seq	The sequence to update cache for

Implements data::LedgerCacheInterface.

update() [2/2]

void data::LedgerCache::update ( std::vector< LedgerObject > const & objs, uint32_t seq, bool isBackground )

overridevirtual

Update the cache with new ledger objects.

Parameters

objs	The ledger objects to update cache with
seq	The sequence to update cache for
isBackground	Should be set to true when writing old data from a background thread

Implements data::LedgerCacheInterface.

waitUntilCacheContainsSeq()

void data::LedgerCache::waitUntilCacheContainsSeq ( uint32_t seq )

overridevirtual

Waits until the cache contains a specific sequence.

Parameters

seq	The sequence to wait for

Implements data::LedgerCacheInterface.

---

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

• /__w/clio/clio/src/data/LedgerCache.hpp
• /__w/clio/clio/src/data/LedgerCache.cpp