Class CMemPagePool

class CMemPagePool : public CBase, public MPagePool;

Description

Uses memory to implement the MPagePool page pool interface.

The class allocates pages from the default heap, storing them in an array. This pool is not persistent.

Derivation

• MPagePool - Interface to a page pool, the storage abstraction used by the B-trees API.
• CBase - Base class for all classes to be instantiated on the heap.

• CMemPagePool - Uses memory to implement the MPagePool page pool interface.

Members

Defined in CMemPagePool:

• AcquireL()For memory-based pools, there is no need to abandon pages, so the function retur...
• AllocL()Allocates a new unassigned page.
• AssignL(const TAny *,TPageReclamation)
• CMemPagePool()Default constructor.
• DoDeleteL(TPageRef)
• LockL(TPageRef)Returns a pointer to a specified page.
• NewL()Allocates and constructs a new CMemPagePool object.
• NewLC()Allocates and constructs a new CMemPagePool object, and leaves it on the cleanup...
• Unlock(const TAny *,TPageChange)Unlocks a page.
• UpdateL(const TAny *)Updates a page.
• ~CMemPagePool()Destructor.

Inherited from CBase:

• Delete(CBase *)Deletes the specified object.
• Extension_(TUint,TAny *&,TAny *)Extension function
• operator new(TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TAny *)Initialises the object to binary zeroes.
• operator new(TUint,TLeave)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TLeave,TUint)Allocates the object from the heap and then initialises its contents to binary z...
• operator new(TUint,TUint)Allocates the object from the heap and then initialises its contents to binary z...

Inherited from MPagePool:

• Delete(TPageRef)Deletes a page, ignoring any errors.
• DeleteL(TPageRef)Deletes a page, leaving if an error occurs.
• Pop()Do a pop from the cleanup stack.
• PushL()Pushes this object onto the cleanup stack.

IMPORT_C static CMemPagePool* NewL();

Description

Allocates and constructs a new CMemPagePool object.

Return value

CMemPagePool * New CMemPagePool object

IMPORT_C static CMemPagePool* NewLC();

Description

Allocates and constructs a new CMemPagePool object, and leaves it on the cleanup stack.

Return value

CMemPagePool * New CMemPagePool object

IMPORT_C CMemPagePool();

Description

Default constructor.

IMPORT_C ~CMemPagePool();

Description

Destructor.

On destruction, memory for all pages is freed.

IMPORT_C virtual TPageAbandonFunction AcquireL();

Description

For memory-based pools, there is no need to abandon pages, so the function returned does nothing.

Return value

TPageAbandonFunction Function that does nothing.

IMPORT_C virtual TAny* AllocL();

Description

Allocates a new unassigned page.

Return value

TAny * Newly allocated page.

IMPORT_C virtual TAny* LockL(TPageRef aRef);

Description

Returns a pointer to a specified page.

Parameters

TPageRef aRef Reference to the page to get

Return value

TAny * Page specified by aRef

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

Description

Parameters

const TAny *aPage TPageReclamation aReclamation

Return value

TPageRef

IMPORT_C virtual void UpdateL(const TAny *aPage);

Description

Updates a page.

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

Parameters

const TAny *aPage Page to update

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

Description

Unlocks a page.

Parameters

const TAny *aPage Page to unlock TPageChange aChange How the page should be treated once it is unlocked

protected: IMPORT_C virtual void DoDeleteL(TPageRef aRef);

Description

Parameters

TPageRef aRef