Class MPagePool

class MPagePool;

Description

Interface to a page pool, the storage abstraction used by the B-trees API.

The interface is abstract and handles pages as TAny pointers. It is left to derived classes to implement page storage in a particular storage medium, such as memory or disk.

Members

Defined in MPagePool:

• AcquireL()Returns a function that abandons all locked pages for this page pool.
• AllocL()
• AssignL(const TAny *,TPageReclamation)
• Delete(TPageRef)Deletes a page, ignoring any errors.
• DeleteL(TPageRef)Deletes a page, leaving if an error occurs.
• DoDeleteL(TPageRef)
• LockL(TPageRef)Locks a page and returns a pointer to it.
• Pop()Do a pop from the cleanup stack.
• PushL()Pushes this object onto the cleanup stack.
• Unlock(const TAny *,TPageChange)Unlocks a page.
• UpdateL(const TAny *)Updates a page.

IMPORT_C void PushL();

Description

Pushes this object onto the cleanup stack.

inline void Pop();

Description

Do a pop from the cleanup stack.

virtual TPageAbandonFunction AcquireL()=0;

Description

Returns a function that abandons all locked pages for this page pool.

Return value

virtual TAny* AllocL()=0;

Description

Return value

virtual TAny* LockL(TPageRef aRef)=0;

Description

Locks a page and returns a pointer to it.

Parameters

Return value

virtual TPageRef AssignL(const TAny *aPage, TPageReclamation aReclamation=EPageDeleteOnly)=0;

Description

Parameters

Return value

virtual void UpdateL(const TAny *aPage)=0;

Description

Updates a page.

This can be used for cached pages that may have become outdated.

Parameters

virtual void Unlock(const TAny *aPage, TPageChange aChange=EPageNoChange)=0;

Description

Unlocks a page.

Parameters

IMPORT_C void Delete(TPageRef aRef);

Description

Deletes a page, ignoring any errors.

Parameters

IMPORT_C void DeleteL(TPageRef aRef);

Description

Deletes a page, leaving if an error occurs.

Parameters

protected: virtual void DoDeleteL(TPageRef aRef)=0;

Description

Parameters