QtDataSync::Defaults Class Reference

A helper class to get defaults per datasync instance (threadsafe) More...

#include <defaults.h>

Public Types
enum	PropertyKey {   CacheSize, PersistDeleted, ConflictPolicy, SslConfiguration,   RemoteConfiguration, KeyStoreProvider, SignScheme, SignKeyParam,   CryptScheme, CryptKeyParam, SymScheme, SymKeyParam,   EventLoggingMode }
	The keys of special properties set on the defaults. More...

Public Member Functions
	Defaults ()
	Default constructor. Constructs an invalid defaults object.
	Defaults (const Defaults &other)
	Copy constructor.
	Defaults (Defaults &&other) noexcept
	Move constructor.
Defaults &	operator= (const Defaults &other)
	Copy assignment operator.
Defaults &	operator= (Defaults &&other) noexcept
	Move assignment operator.
bool	isValid () const
	Checks if the current defaults are valid. Default constructed defaults are invalid.
void	drop ()
	Drops the reference to the defaults early.
Logger *	createLogger (const QByteArray &subCategory, QObject *parent=nullptr) const
	Create a new logger instance. More...
QString	setupName () const
	Returns the name of the current setup.
QDir	storageDir () const
	Returns the storage directory. More...
QUrl	remoteAddress () const
	Returns the url to use for the remote object connection. More...
QRemoteObjectNode *	remoteNode () const
	Returns the remote object node for the current thread to connect to the engine. More...
QSettings *	createSettings (QObject *parent=nullptr, const QString &group={}) const
	Returns a new instance of QSettings for this setup. More...
const QJsonSerializer *	serializer () const
	Returns the serializer of the current setup. More...
const ConflictResolver *	conflictResolver () const
	Returns the conflict resolver of the current setup. More...
QVariant	property (PropertyKey key) const
	Returns the extra property defined by the given key. More...
DatabaseRef	aquireDatabase (QObject *object) const
	Aquire a reference to the standard sqlite database. More...

Static Public Member Functions
static QVariant	defaultParam (Setup::SignatureScheme scheme)
	Returns the standard key parameter for the given signature scheme. More...
static QVariant	defaultParam (Setup::EncryptionScheme scheme)
	Returns the standard key parameter for the given encryption scheme. More...

Detailed Description

A helper class to get defaults per datasync instance (threadsafe)

This class is internally used to easily get "defaults" that vary between different setups. Unless you are extending data sync with a custom implementation, this class has no relevance for you. The things you can access from the defaults are all defined by the Setup.

Using this defaults provides save storage locations, settings, logging and more, that won't interfere with other instances of data sync. If you need to store files, settings or do some logging, you should use this defaults to do so.

See also

Setup

Definition at line 61 of file defaults.h.

Member Enumeration Documentation

PropertyKey

enum QtDataSync::Defaults::PropertyKey

The keys of special properties set on the defaults.

For a more details explanation, see property()

See also

Defaults::property

Enumerator
CacheSize	The size of the internal database cache, in bytes.
PersistDeleted	Specify whether deleted datasets should persist.
ConflictPolicy	The policiy for how to handle conflicts.
SslConfiguration	The ssl configuration to be used to connect to the remote.
RemoteConfiguration	The configuration to be used to connect to the remote.
KeyStoreProvider	The name of the preferred keystore provider.
SignScheme	The algorithmic scheme to be used for new signature keys.
SignKeyParam	The generation parameter for the signature key.
CryptScheme	The algorithmic scheme to be used for new encryption keys.
CryptKeyParam	The generation parameter for the encryption key.
SymScheme	The algorithmic scheme to be used for new secret exchange keys (which are symmetric)
SymKeyParam	The size in bytes for the secret exchange key (which is symmetric)
EventLoggingMode	The logging mode for database change events.

Definition at line 68 of file defaults.h.

Member Function Documentation

aquireDatabase()

QtDataSync::Defaults::aquireDatabase

(

QObject *

object

)

const

Aquire a reference to the standard sqlite database.

Parameters

object

The object the wants the reference.

Returns

An instance of the local sqlite database, wrapped in a database ref

If you are working with sqlite databases, you can use this function to get a reference to one. This allows multiple components to share one database, instead of create many. Of cause, this means will will have to be careful to not interfere with the data of other components. The database itself will be created inside the storage directory. Reference counting is used to automatically clean up connections. See the DatabaseRef documentation.

The object is used to install an event filter to detect if the object was moved to a different thread. This is needed, as a connection is only valid per thread, and thus changing a thread means creating a new connection. This is completly handeled internally, so it is save to move the databaseref to another thread via that object.

See also

DatabaseRef, Defaults::storageDir

conflictResolver()

QtDataSync::Defaults::conflictResolver

(

)

const

Returns the conflict resolver of the current setup.

Returns

The conflict resolver. Can be nullptr

An optional conflict resolver used to handle merge conflicts. Is null by default, but can be set by the setup.

Attention

This instance is shared across the whole setup, do not delete or change it, use it only to resolve conflicts. Please do not const_cast it ;)

See also

Setup::conflictResolver, ConflictResolver

createLogger()

QtDataSync::Defaults::createLogger	(	const QByteArray &	subCategory,
		QObject *	parent = nullptr
	)		const

Create a new logger instance.

Parameters

subCategory	The sub category, passed to the logger constructor
parent	The object parent of the created logger

Returns

A new created instance of a logger

Uses the setup this defaults belong to and the passed category to create a logger. Read the Logger documentation for more details. The returned logger is owner by the caller (or the parent) and will use the subCategory for the logging string.

See also

Logger

createSettings()

QtDataSync::Defaults::createSettings	(	QObject *	parent = nullptr,
		const QString &	group = {}
	)		const

Returns a new instance of QSettings for this setup.

Parameters

parent	The parent object for the settings
group	A sub-group to use as root for the returned settings

Returns

A newly created settings instance

Creates a QSettings instance that will persist data for this setup. The settings reside inside of the settings storage directory, and thus are not bound to the setup name. If you want to store data persistently, like usernames etc, use this settings.

Note

You should always pass a group that idenfifies your component. This keeps the settings clean and prevents naming conflicts with other components.

See also

Defaults::storageDir

defaultParam() [1/2]

QtDataSync::Defaults::defaultParam ( Setup::SignatureScheme  scheme )

static

Returns the standard key parameter for the given signature scheme.

Returns

The default key parameter for the given scheme

If the Setup::signatureKeyParam is an invalid QVariant, this method can be used to obtain the default value for the corresponding signature scheme. For more details on what this parameter is for each scheme, check the setups key param documentation.

See also

Setup::signatureScheme, Setup::signatureKeyParam

defaultParam() [2/2]

QtDataSync::Defaults::defaultParam ( Setup::EncryptionScheme  scheme )

static

Returns the standard key parameter for the given encryption scheme.

Returns

The default key parameter for the given scheme

If the Setup::encryptionKeyParam is an invalid QVariant, this method can be used to obtain the default value for the corresponding encryption scheme. For more details on what this parameter is for each scheme, check the setups key param documentation.

See also

Setup::encryptionScheme, Setup::encryptionKeyParam

property()

QtDataSync::Defaults::property

(

PropertyKey

key

)

const

Returns the extra property defined by the given key.

Parameters

key	The key of the property to be obtained

Returns

The value of the stored property for that key.

This method is used instead of many direct methods to obtains various extra properties passed from the setup. The following table shows what these are. Please read the documentation of the corresponsing Setup properties for more details on what these properties mean in details and how they may be used internally.

Key	Type	Setup property
Defaults::CacheSize	int	Setup::cacheSize
Defaults::PersistDeleted	bool	Setup::persistDeletedVersion
Defaults::ConflictPolicy	Setup::SyncPolicy	Setup::syncPolicy
Defaults::SslConfiguration	QSslConfiguration	Setup::sslConfigurationn
Defaults::RemoteConfiguration	RemoteConfig	Setup::remoteConfiguration
Defaults::KeyStoreProvider	QString	Setup::keyStoreProvider
Defaults::SignScheme	Setup::SignatureScheme	Setup::signatureScheme
Defaults::SignKeyParam	QVariant	Setup::signatureKeyParam
Defaults::CryptScheme	Setup::EncryptionScheme	Setup::encryptionScheme
Defaults::CryptKeyParam	QVariant	Setup::encryptionKeyParam
Defaults::SymScheme	Setup::CipherScheme	Setup::cipherScheme
Defaults::SymKeyParam	qint32	Setup::cipherKeySize

See also

Defaults::PropertyKey, Setup

remoteAddress()

QtDataSync::Defaults::remoteAddress

(

)

const

Returns the url to use for the remote object connection.

Returns

The url of the remote object host created by the engine

Use this address to create QRemoteObjectNode instances to connect to the engines host node. Typically you can use remoteNode() directly, as this one works threadsafe.

See also

Defaults::remoteNode, Setup::remoteObjectHost

remoteNode()

QtDataSync::Defaults::remoteNode

(

)

const

Returns the remote object node for the current thread to connect to the engine.

Returns

A remote node for the current thread connected to the engines host node

The method creates a node for each thread and cleans them up automatically. The returned node is connected to the engines host node, and thus can be immediatly used to obtain replicas. If you need the url used to connect, see remoteAddress().

Note

Even though this method is threadsafe, the returned node is not. If you need to switch the thread, call this method again on the new thread to obtain a new node for that thread. If you don't, replicas of the new thread will not work.

See also

Defaults::remoteAddress, Setup::remoteObjectHost

serializer()

QtDataSync::Defaults::serializer

(

)

const

Returns the serializer of the current setup.

Returns

The json serializer

The serializer is the one used by datasync internally. If you need to de/serializer data in your custom implementations, make shure to use this one.

Attention

This instance is shared across the whole setup, do not delete or change it, use it only to de/serializer data. Please do not const_cast it ;)

See also

Setup::serializer, QJsonSerializer

storageDir()

QtDataSync::Defaults::storageDir

(

)

const

Returns the storage directory.

Returns

The local storage directory

The storage directory contains everything regarding configuration and data, and thus basically identifies the datasync instance. It is also used for locking.

When implementing a part of qtdatasync, you may need to store data on the local file system. You should always store data inside this folder. Consider it your "root folder". Storing in different locations can lead to undefined behaviour. Of cause you can create subdirs etc inside this folder as you please. However, there are some special files, like the lock file or the settings you should not modify yourself.

See also

Defaults::createSettings, Setup::localDir

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

• defaults.h
• defaults.dox