Database abstraction. More...

Public Member Functions
	Base (const QString &name, uint16_t mapSize=10)
	Creates the database.

	~Base ()
	Destroys the database.

void	open ()
	Opens the database.

void	close ()
	Closes the database.

bool	ready () const
	Returns database state.

bool	removeDirectory ()
	Removes database directory.

QString	createDirectory ()
	Creates database directory.

QString	getName () const
	Returns database name.

QString	getPath () const
	Returns database name.

void	drop ()
	Drops the database.

Transaction	beginReadOnlyTransaction () const
	Begins read-only transaction.

WriteTransaction	beginTransaction ()
	Begins writable transaction.

template<class K , class V >
LMDBAL::Storage< K, V > *	addStorage (const std::string &storageName, bool duplicates=false)
	Adds LMDBAL::Storage to the database.

template<class K , class V >
LMDBAL::Cache< K, V > *	addCache (const std::string &storageName)
	Adds LMDBAL::Cache to the database.

template<class K , class V >
LMDBAL::Storage< K, V > *	getStorage (const std::string &storageName)
	Returns LMDBAL::Storage handle.

template<class K , class V >
LMDBAL::Cache< K, V > *	getCache (const std::string &storageName)
	Returns LMDBAL::Cache handle.

Friends
class	iStorage

class	Transaction

class	WriteTransaction

Detailed Description

Database abstraction.

This is a basic class that represents the database as a collection of storages. Storages is something key-value database has instead of tables in classic SQL databases.

Constructor & Destructor Documentation

◆ Base()

LMDBAL::Base::Base	(	const QString &	_name,
		uint16_t	_mapSize = `10`
	)

Creates the database.

Parameters

[in]	_name	- name of the database, it is going to affect folder name that is created to store data
[in]	_mapSize	- LMDB map size (MiB), multiplied by 1024^2 and passed to mdb_env_set_mapsize during the call of LMDBAL::Base::open()

Member Function Documentation

◆ addCache()

template<class K , class V >

LMDBAL::Cache< K, V > * LMDBAL::Base::addCache ( const std::string & storageName )

Adds LMDBAL::Cache to the database.

Defines that the database is going to have the following cache. The LMDBAL::Base must be closed

Parameters

[in] storageName - cache name

Returns: cache pointer. LMDBAL::Base keeps the ownership of the added cache, you don't need to destoroy it

Template Parameters

K	- key type of the cache
V	- value type of the cahce

Exceptions

LMDBAL::Opened	thrown if this method is called on the opened database
LMDBAL::StorageDuplicate	thrown if somebody tries to add cache with repeating name

◆ addStorage()

template<class K , class V >

LMDBAL::Storage< K, V > * LMDBAL::Base::addStorage	(	const std::string &	storageName,
		bool	duplicates = `false`
	)

Adds LMDBAL::Storage to the database.

Defines that the database is going to have the following storage. The LMDBAL::Base must be closed

Parameters

[in]	storageName	- storage name
[in]	duplicates	- true if key duplicates are allowed (false by default)

Returns: storage pointer. LMDBAL::Base keeps the ownership of the added storage, you don't need to destoroy it

Template Parameters

K	- key type of the storage
V	- value type of the storage

Exceptions

LMDBAL::Opened	thrown if this method is called on the opened database
LMDBAL::StorageDuplicate	thrown if somebody tries to add storage with repeating name

◆ beginReadOnlyTransaction()

LMDBAL::Transaction LMDBAL::Base::beginReadOnlyTransaction ( ) const

Begins read-only transaction.

This is the legitimate way to retrieve LMDBAL::Transaction. LMDBAL::Transaction is considered runnig right after creation by this method. You can terminate transaction manually calling LMDBAL::Transaction::terminate but it's not required, because transaction will be terminated automatically (if it was not terminated manually) upon the call of the destructor.

You can not use termitated transaction any more.

Returns: read-only transaction

Exceptions

LMDBAL::Closed	- thrown if the database is closed
LMDBAL::Unknown	- thrown if something unexpected happened

◆ beginTransaction()

LMDBAL::WriteTransaction LMDBAL::Base::beginTransaction ( )

Begins writable transaction.

This is the legitimate way to retrieve LMDBAL::WriteTransaction. LMDBAL::WriteTransaction is considered runnig right after creation by this method. You can commit all the changes made by this transaction calling LMDBAL::WriteTransaction::commit. You can cancel any changes made bu this transaction calling LMDBAL::WriteTransaction::abort (or LMDBAL::Transaction::terminate which LMDBAL::WriteTransaction inherits), but it's not required, because transaction will be aborted automatically (if it was not terminated (committed OR aborted) manually) upon the call of the destructor.

You can not use termitated transaction any more.

Returns: writable transaction

Exceptions

LMDBAL::Closed	- thrown if the database is closed
LMDBAL::Unknown	- thrown if something unexpected happened

◆ close()

void LMDBAL::Base::close ( )

Closes the database.

Closes all lmdb handles, aborts all public transactions. This function will do nothing on closed database

Exceptions

LMDBAL::Unknown - thrown if something went wrong aborting transactions

◆ createDirectory()

QString LMDBAL::Base::createDirectory ( )

Creates database directory.

Creates or opens existing directory with the given name in the location acquired with QStandardPaths::writableLocation(QStandardPaths::CacheLocation) so, the file system destination of your data would depend on the QCoreApplication configuration of your app. This function does nothing if the directory was already created

Returns: the path of the created directory

Exceptions

LMDBAL::Opened	- thrown if called on opened database
LMDBAL::Directory	- if the database couldn't create the folder

◆ drop()

void LMDBAL::Base::drop ( )

Drops the database.

Clears all caches and storages of the database

Exceptions

LMDBAL::Closed	- thrown if the database is closed
LMDBAL::Unknown	- thrown if something unexpected happend

◆ getCache()

template<class K , class V >

LMDBAL::Cache< K, V > * LMDBAL::Base::getCache ( const std::string & storageName )

Returns LMDBAL::Cache handle.

Requested cache must have been added before opening database Note that template parameters is user responsibility zone! If user, for instance, had added cache <int, int> but calling this method with template parameters <std::string, std::string> on the same name of the previously added cache, or calling it on storage - the behaviour is undefined

Parameters

[in] storageName - cache name

Returns: cache pointer. LMDBAL::Base keeps the ownership of the added cache, you don't need to destoroy it

Template Parameters

K	- key type of the cache
V	- value type of the cahce

Exceptions

std::out_of_range thrown if cache with the given name was not found

◆ getName()

QString LMDBAL::Base::getName ( ) const

Returns database name.

Returns: database name

◆ getPath()

QString LMDBAL::Base::getPath ( ) const

Returns database name.

Returns: database path

◆ getStorage()

template<class K , class V >

LMDBAL::Storage< K, V > * LMDBAL::Base::getStorage ( const std::string & storageName )

Returns LMDBAL::Storage handle.

Requested storage must have been added before opening database Note that template parameters is user responsibility zone! If user, for instance, had added storage <int, int> but calling this method with template parameters <std::string, std::string> on the same name of the previously added storage, or calling it on cache - the behaviour is undefined

Parameters

[in] storageName - storage name

Returns: storage pointer. LMDBAL::Base keeps the ownership of the added storage, you don't need to destoroy it

Template Parameters

K	- key type of the storage
V	- value type of the storage

Exceptions

std::out_of_range thrown if storage with the given name was not found

◆ open()

void LMDBAL::Base::open ( )

Opens the database.

Almost every LMDBAL::Base require it to be opened, this function does it. It laso creates the directory for the database if it was an initial launch. This function will do nothing on opened database

Exceptions

LMDBAL::Unknown - thrown if something went wrong opening storages and caches

◆ ready()

bool LMDBAL::Base::ready ( ) const

Returns database state.

Returns: true if the database is opened and ready for work, false otherwise

◆ removeDirectory()

bool LMDBAL::Base::removeDirectory ( )

Removes database directory.

Returns: true if removal was successfull of if no directory was created where it's expected to be, false otherwise

Exceptions

LMDBAL::Opened - thrown if this function was called on opened database

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

/workspace/blue/lmdbal/src/base.h
/workspace/blue/lmdbal/src/base.cpp

Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Base()

Member Function Documentation

◆ addCache()

◆ addStorage()

◆ beginReadOnlyTransaction()

◆ beginTransaction()

◆ close()

◆ createDirectory()

◆ drop()

◆ getCache()

◆ getName()

◆ getPath()

◆ getStorage()

◆ open()

◆ ready()

◆ removeDirectory()