Class TCachePagePool

TCachePagePool

Description

Provides a page pool with cached pages.

It is an intermediary class, used in the definition of page pools that use a cache, such as RFilePagePool and RStorePagePool.

Derivation

MPagePool Interface to a page pool, the storage abstraction used by the B-trees API TCachePagePool Provides a page pool with cached pages

Defined in TCachePagePool:
AcquireL(), AllocL(), AssignL(), Flush(), FlushL(), LockL(), Purge(), Set(), Unlock(), UpdateL()

Inherited from MPagePool:
Delete(), DeleteL(), Pop(), PushL()

See also:

• RFilePagePool
• RStorePagePool

TPageAbandonFunction AcquireL();

Description

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

Return value

TPageAbandonFunction A function that abandons all locked pages for this page pool.

TAny* AllocL();

Description

Allocates an unassigned page.

Return value

TAny* Newly allocated page.

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

Description

Assigns a reference to a new page and unlocks it.

Parameters

const TAny* aPage Page to assign TPageReclamation aReclamation=EPageDeleteOnly Flag for page reclaimation settings

Return value

TPageRef Reference to page

TInt Flush();

Description

Flush all pages in this pool from the cache.

It ensures that any dirty pages are written into persistent storage, but does not remove them from the cache.

Return value

TInt KErrNone if successful, otherwise another of the system-wide error codes.

void FlushL();

Description

Flushes all pages in this pool from the cache, leaving with a system-wide error code if an error occurs.

TAny* LockL(TPageRef aRef);

Description

Locks a page and returns a pointer to it.

Parameters

TPageRef aRef Reference to page to lock

Return value

TAny* Locked page

void Purge();

Description

Purge all pages in this pool from the cache.

This discards all pages from the cache, without saving dirty pages.

void Set(CPageCache& aCache);

Description

Sets the page cache for the pool.

Parameters

CPageCache& aCache The page cache for the pool.

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

Description

Unlocks a page.

Parameters

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

void UpdateL(const TAny* aPage);

Description

Updates a page.

Parameters

const TAny* aPage Page to update