A backend used for the NodeStore. More...

Inheritance diagram for ripple::NodeStore::Backend:

[legend]

Classes
struct	Counters

Public Member Functions
virtual	~Backend ()=default
	Destroy the backend. More...

virtual std::string	getName ()=0
	Get the human-readable name of this backend. More...

virtual void	open (bool createIfMissing=true)=0
	Open the backend. More...

virtual bool	isOpen ()=0
	Returns true is the database is open. More...

virtual void	open (bool createIfMissing, uint64_t appType, uint64_t uid, uint64_t salt)
	Open the backend. More...

virtual void	close ()=0
	Close the backend. More...

virtual Status	fetch (void const key, std::shared_ptr< NodeObject > pObject)=0
	Fetch a single object. More...

virtual std::pair< std::vector< std::shared_ptr< NodeObject > >, Status >	fetchBatch (std::vector< uint256 const * > const &hashes)=0
	Fetch a batch synchronously. More...

virtual void	store (std::shared_ptr< NodeObject > const &object)=0
	Store a single object. More...

virtual void	storeBatch (Batch const &batch)=0
	Store a group of objects. More...

virtual void	sync ()=0

virtual void	for_each (std::function< void(std::shared_ptr< NodeObject >)> f)=0
	Visit every object in the database This is usually called during import. More...

virtual int	getWriteLoad ()=0
	Estimate the number of write operations pending. More...

virtual void	setDeletePath ()=0
	Remove contents on disk upon destruction. More...

virtual void	verify ()
	Perform consistency checks on database. More...

virtual int	fdRequired () const =0
	Returns the number of file descriptors the backend expects to need. More...

virtual std::optional< Counters< std::uint64_t > >	counters () const
	Returns read and write stats. More...

Detailed Description

A backend used for the NodeStore.

The NodeStore uses a swappable backend so that other database systems can be tried. Different databases may offer various features such as improved performance, fault tolerant or distributed storage, or all in-memory operation.

A given instance of a backend is fixed to a particular key size.

Definition at line 39 of file Backend.h.

Constructor & Destructor Documentation

◆ ~Backend()

virtual ripple::NodeStore::Backend::~Backend ( )

virtualdefault

Destroy the backend.

All open files are closed and flushed. If there are batched writes or other tasks scheduled, they will be completed before this call returns.

Member Function Documentation

◆ getName()

virtual std::string ripple::NodeStore::Backend::getName ( )

pure virtual

Get the human-readable name of this backend.

This is used for diagnostic output.

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ open() [1/2]

virtual void ripple::NodeStore::Backend::open ( bool createIfMissing = true )

pure virtual

Open the backend.

Parameters

createIfMissing Create the database files if necessary. This allows the caller to catch exceptions.

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ isOpen()

virtual bool ripple::NodeStore::Backend::isOpen ( )

pure virtual

Returns true is the database is open.

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ open() [2/2]

virtual void ripple::NodeStore::Backend::open	(	bool	createIfMissing,
		uint64_t	appType,
		uint64_t	uid,
		uint64_t	salt
	)

virtual

Open the backend.

Parameters

createIfMissing	Create the database files if necessary.
appType	Deterministic appType used to create a backend.
uid	Deterministic uid used to create a backend.
salt	Deterministic salt used to create a backend.

Exceptions

std::runtime_error is function is called not for NuDB backend.

Reimplemented in ripple::NodeStore::NuDBBackend.

Definition at line 99 of file Backend.h.

◆ close()

virtual void ripple::NodeStore::Backend::close ( )

pure virtual

Close the backend.

This allows the caller to catch exceptions.

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ fetch()

virtual Status ripple::NodeStore::Backend::fetch	(	void const *	key,
		std::shared_ptr< NodeObject > *	pObject
	)

pure virtual

Fetch a single object.

If the object is not found or an error is encountered, the result will indicate the condition.

Note: This will be called concurrently.

Parameters

key	A pointer to the key data.
pObject	[out] The created object if successful.

Returns: The result of the operation.

Implemented in ripple::NodeStore::MemoryBackend, ripple::NodeStore::NuDBBackend, and ripple::NodeStore::NullBackend.

◆ fetchBatch()

virtual std::pair<std::vector<std::shared_ptr<NodeObject> >, Status> ripple::NodeStore::Backend::fetchBatch ( std::vector< uint256 const * > const & hashes )

pure virtual

Fetch a batch synchronously.

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ store()

virtual void ripple::NodeStore::Backend::store ( std::shared_ptr< NodeObject > const & object )

pure virtual

Store a single object.

Depending on the implementation this may happen immediately or deferred using a scheduled task.

Note: This will be called concurrently.

Parameters

object The object to store.

Implemented in ripple::NodeStore::MemoryBackend, ripple::NodeStore::NullBackend, and ripple::NodeStore::NuDBBackend.

◆ storeBatch()

virtual void ripple::NodeStore::Backend::storeBatch ( Batch const & batch )

pure virtual

Store a group of objects.

Note: This function will not be called concurrently with itself or store.

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ sync()

virtual void ripple::NodeStore::Backend::sync ( )

pure virtual

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ for_each()

virtual void ripple::NodeStore::Backend::for_each ( std::function< void(std::shared_ptr< NodeObject >)> f )

pure virtual

Visit every object in the database This is usually called during import.

Note: This routine will not be called concurrently with itself or other methods.

See also: import

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ getWriteLoad()

virtual int ripple::NodeStore::Backend::getWriteLoad ( )

pure virtual

Estimate the number of write operations pending.

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ setDeletePath()

virtual void ripple::NodeStore::Backend::setDeletePath ( )

pure virtual

Remove contents on disk upon destruction.

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ verify()

virtual void ripple::NodeStore::Backend::verify ( )

virtual

Perform consistency checks on database.

This method is implemented only by NuDBBackend. It is not yet called anywhere, but it might be a good idea to one day call it at startup to avert a crash.

Reimplemented in ripple::NodeStore::NuDBBackend.

Definition at line 170 of file Backend.h.

◆ fdRequired()

virtual int ripple::NodeStore::Backend::fdRequired ( ) const

pure virtual

Returns the number of file descriptors the backend expects to need.

Implemented in ripple::NodeStore::NuDBBackend, ripple::NodeStore::MemoryBackend, and ripple::NodeStore::NullBackend.

◆ counters()

virtual std::optional<Counters<std::uint64_t> > ripple::NodeStore::Backend::counters ( ) const

virtual

Returns read and write stats.

Note: The Counters struct is specific to and only used by CassandraBackend.

Definition at line 184 of file Backend.h.

Classes

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ ~Backend()

Member Function Documentation

◆ getName()

◆ open() [1/2]

◆ isOpen()

◆ open() [2/2]

◆ close()

◆ fetch()

◆ fetchBatch()

◆ store()

◆ storeBatch()

◆ sync()

◆ for_each()

◆ getWriteLoad()

◆ setDeletePath()

◆ verify()

◆ fdRequired()

◆ counters()