XCachedHash Class 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 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
void	setNotification (QStringList pNotification)

Protected Attributes
QSqlDatabase	_db

Detailed Description

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()

virtual XCachedHash::~XCachedHash ( )

inlinevirtual

XCachedHash() [1/2]

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

inlineprotected

XCachedHash() [2/2]

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

inlineprotected

Member Function Documentation

clear()

virtual void XCachedHash::clear ( )

inlineprotectedvirtual

refresh()

virtual bool XCachedHash::refresh ( const K &  key )

protectedpure virtual

setNotification()

void XCachedHash::setNotification ( QStringList  pNotification )

inlineprotected

value()

virtual const V XCachedHash::value ( const K &  key )

inlinevirtual

Member Data Documentation

_db

QSqlDatabase XCachedHash::_db

protected

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

• xcachedhash.h