XCachedHash< K, V > Class Template Reference

The XCachedHash combines a templated QHash with a QObject that clears itself upon receipt of a specific database notification or set of notifications. More...

#include <xcachedhash.h>

Public Slots
virtual void	sConnectionLost ()
virtual void	sNotified (const QString &pNotification)

Public Member Functions
virtual	~XCachedHash ()
virtual const V	value (const K &key)

Protected Member Functions
	XCachedHash (QObject *pParent, const QStringList &pNotification, QSqlDatabase pDb=QSqlDatabase::database())
	XCachedHash (QObject *pParent=0, const QString &pNotification=QString(), QSqlDatabase pDb=QSqlDatabase::database())
virtual void	clear ()
virtual bool	refresh (const K &key)=0
virtual void	setNotification (QStringList pNotification)

Protected Attributes
QSqlDatabase	_db
QStringList	_notice

Detailed Description

template<class K, class V>
class XCachedHash< K, V >

The XCachedHash combines a templated QHash with a QObject that clears itself upon receipt of a specific database notification or set of notifications.

This allows for straightforward access to a named object that's stored in the database, such as a script or metasql statement with minimal database access. The database is queried whenever a named object is not in the hash. The value retrieved from the database is stored in the hash and returned to the caller. The next time a caller requests that object, it is returned from the hash directly. The hash clears itself when the named database notification is received. Thus the next time a caller requests that named object, the hash requeries.

This is currently designed to be subclassed.

See also

MqlHash for an example.

Constructor & Destructor Documentation

~XCachedHash()

template<class K , class V >

virtual XCachedHash< K, V >::~XCachedHash ( )

inlinevirtual

XCachedHash() [1/2]

template<class K , class V >

XCachedHash< K, V >::XCachedHash ( QObject * pParent = 0, const QString & pNotification = QString(), QSqlDatabase pDb = QSqlDatabase::database() )

inlineprotected

XCachedHash() [2/2]

template<class K , class V >

XCachedHash< K, V >::XCachedHash ( QObject * pParent, const QStringList & pNotification, QSqlDatabase pDb = QSqlDatabase::database() )

inlineprotected

Member Function Documentation

clear()

template<class K , class V >

virtual void XCachedHash< K, V >::clear ( )

inlineprotectedvirtual

Implements XCachedHashQObject.

refresh()

template<class K , class V >

virtual bool XCachedHash< K, V >::refresh ( const K & key )

protectedpure virtual

Implemented in MqlHash.

sConnectionLost

void XCachedHashQObject::sConnectionLost ( )

virtualslotinherited

setNotification()

template<class K , class V >

virtual void XCachedHash< K, V >::setNotification ( QStringList pNotification )

inlineprotectedvirtual

sNotified

void XCachedHashQObject::sNotified ( const QString & pNotification )

virtualslotinherited

value()

template<class K , class V >

virtual const V XCachedHash< K, V >::value ( const K & key )

inlinevirtual

Member Data Documentation

_db

template<class K , class V >

QSqlDatabase XCachedHash< K, V >::_db

protected

_notice

QStringList XCachedHashQObject::_notice

protectedinherited

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

• xcachedhash.h