This namespace implements the data access layer and related components. More...

Namespaces
namespace	cassandra
	This namespace implements a wrapper for the Cassandra C++ driver.

Classes
struct	Amendment
	Represents an amendment in the XRPL. More...
class	AmendmentCenter
	Knowledge center for amendments within XRPL. More...
class	AmendmentCenterInterface
	The interface of an amendment center. More...
struct	AmendmentKey
	A helper for amendment name to feature conversions. More...
struct	Amendments
	List of supported amendments. More...
class	BackendCounters
	Holds statistics about the backend. More...
class	BackendInterface
	The interface to the database used by Clio. More...
struct	BookOffersPage
	Represents a page of book offer objects. More...
class	DatabaseError
	Represents a transient database error that the caller should retry. More...
class	FetchLedgerCache
	A simple cache holding one xrpl::LedgerHeader to reduce DB lookups. More...
class	LedgerCache
	Cache for an entire ledger. More...
class	LedgerCacheInterface
	Cache for an entire ledger. More...
class	LedgerCacheLoadingState
	Concrete implementation of LedgerCacheLoadingStateInterface. More...
class	LedgerCacheLoadingStateInterface
	Interface for coordinating cache loading permissions across a cluster. More...
class	LedgerCacheSaver
	Manages asynchronous saving of ledger cache to a file. More...
struct	LedgerObject
	Represents an object in the ledger. More...
struct	LedgerPage
	Represents a page of LedgerObjects. More...
struct	LedgerRange
	Stores a range of sequences as a min and max pair. More...
struct	MPTHoldersAndCursor
	Represents an array of MPTokens. More...
struct	NFT
	Represents a NFToken. More...
struct	NFTsAndCursor
	Represents a bundle of NFTs with a cursor to the next page. More...
struct	TransactionAndMetadata
	Represents a transaction and its metadata bundled together. More...
struct	TransactionsAndCursor
	Represests a bundle of transactions with metadata and a cursor to the next page. More...
struct	TransactionsCursor
	Represents a cursor into the transactions table. More...

Concepts
concept	SomeBackendCounters
	A concept for a class that can be used to count backend operations.
concept	SomeLedgerCacheSaver
	A concept for a class that can save ledger cache asynchronously.

Typedefs
using	Blob = std::vector<unsigned char>

Functions
std::shared_ptr< BackendInterface >	makeBackend (util::config::ClioConfigDefinition const &config, data::LedgerCacheInterface &cache)
	A factory function that creates the backend based on a config.
template<typename FnType>
auto	retryOnTimeout (FnType func, boost::asio::yield_context yield, util::Retry::Delays delays=kDefaultRetryDelays)
	Retry func while it throws DatabaseError, suspending the calling coroutine in between.
template<typename FnType>
auto	retryOnTimeout (FnType func, util::Retry::Delays delays=kDefaultRetryDelays)
	Retry func while it throws DatabaseError, blocking the calling thread in between.
template<typename FnType>
auto	synchronous (FnType &&func)
	Synchronously executes the given function object inside a coroutine.
template<typename FnType>
auto	synchronousAndRetryOnTimeout (FnType &&func, util::Retry::Delays delays=kDefaultRetryDelays)
	Synchronously execute the given function object and retry until no DatabaseError is thrown.

Variables
static constexpr std::chrono::milliseconds	kDefaultWaitBetweenRetry {500}
	Delay before the first retry in retryOnTimeout().
static constexpr std::chrono::milliseconds	kMaxWaitBetweenRetry {5'000}
	Default upper bound for the exponential backoff in retryOnTimeout().
static constexpr util::Retry::Delays	kDefaultRetryDelays
	Default delays for retryOnTimeout().
constexpr xrpl::uint256	kFirstKey
constexpr xrpl::uint256	kLastKey
constexpr xrpl::uint256	kHi192 {"0000000000000000000000000000000000000000000000001111111111111111"}

Detailed Description

This namespace implements the data access layer and related components.

The data layer is responsible for fetching and storing data from the database. Cassandra and ScyllaDB are currently supported via the CassandraBackend implementation.

Function Documentation

◆ makeBackend()

std::shared_ptr< BackendInterface > data::makeBackend	(	util::config::ClioConfigDefinition const &	config,
		data::LedgerCacheInterface &	cache )

inline

A factory function that creates the backend based on a config.

Parameters

config	The clio config to use
cache	The ledger cache to use

Returns: A shared_ptr<BackendInterface> with the selected implementation

◆ retryOnTimeout() [1/2]

template<typename FnType>

auto data::retryOnTimeout	(	FnType	func,
		boost::asio::yield_context	yield,
		util::Retry::Delays	delays = kDefaultRetryDelays )

Retry func while it throws DatabaseError, suspending the calling coroutine in between.

Template Parameters

FnType The type of function object to execute

Parameters

func	The function object to execute
yield	The coroutine to suspend between attempts
delays	The delays to use between attempts

Returns: The same as the return type of func

◆ retryOnTimeout() [2/2]

template<typename FnType>

auto data::retryOnTimeout	(	FnType	func,
		util::Retry::Delays	delays = kDefaultRetryDelays )

Retry func while it throws DatabaseError, blocking the calling thread in between.

Warning: Blocks the calling thread; from a coroutine use the yield_context overload instead.

Template Parameters

FnType The type of function object to execute

Parameters

func	The function object to execute
delays	The delays to use between attempts

Returns: The same as the return type of func

◆ synchronous()

template<typename FnType>

auto data::synchronous ( FnType && func )

Synchronously executes the given function object inside a coroutine.

Template Parameters

FnType The type of function object to execute

Parameters

func	The function object to execute

Returns: The same as the return type of func

◆ synchronousAndRetryOnTimeout()

template<typename FnType>

auto data::synchronousAndRetryOnTimeout	(	FnType &&	func,
		util::Retry::Delays	delays = kDefaultRetryDelays )

Synchronously execute the given function object and retry until no DatabaseError is thrown.

Warning: Blocks the calling thread while backing off.

Template Parameters

FnType The type of function object to execute

Parameters

func	The function object to execute
delays	The delays to use between attempts

Returns: The same as the return type of func

Variable Documentation

◆ kDefaultRetryDelays

util::Retry::Delays data::kDefaultRetryDelays

staticconstexpr

Initial value:

{
    .initial = kDefaultWaitBetweenRetry,
    .max = kDefaultWaitBetweenRetry,
}

Default delays for retryOnTimeout().

◆ kFirstKey

xrpl::uint256 data::kFirstKey

constexpr

Initial value:

{
    "0000000000000000000000000000000000000000000000000000000000000000"
}

◆ kLastKey

xrpl::uint256 data::kLastKey

constexpr

Initial value:

{
    "FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
}

Namespaces

Classes

Concepts

Typedefs

Functions

Variables

Detailed Description

Function Documentation

◆ makeBackend()

◆ retryOnTimeout() [1/2]

◆ retryOnTimeout() [2/2]

◆ synchronous()

◆ synchronousAndRetryOnTimeout()

Variable Documentation

◆ kDefaultRetryDelays

◆ kFirstKey

◆ kLastKey