Class TCachePagePool

class TCachePagePool : public MPagePool;

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.

Members

Defined in TCachePagePool:

• AcquireL()Returns a function that abandons all locked pages for this page pool.
• AllocL()Allocates an unassigned page.
• AssignL(const TAny *,TPageReclamation)Assigns a reference to a new page and unlocks it.
• DoDeleteL(TPageRef)
• ExtendL(const TAny *,TPageReclamation)
• Flush()Flush all pages in this pool from the cache.
• FlushL()Flushes all pages in this pool from the cache, leaving with a system-wide error ...
• LockL(TPageRef)Locks a page and returns a pointer to it.
• Purge()Purge all pages in this pool from the cache.
• ReadL(TPageRef,TAny *)
• Set(CPageCache &)Sets the page cache for the pool.
• TCachePagePool()
• TCachePagePool(CPageCache &)
• Unlock(const TAny *,TPageChange)Unlocks a page.
• UpdateL(const TAny *)Updates a page.
• WriteL(TPageRef,const TAny *,TPageChange)

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.

protected: inline TCachePagePool();

Description

protected: inline TCachePagePool(CPageCache &aCache);

Description

Parameters

inline void Set(CPageCache &aCache);

Description

Sets the page cache for the pool.

Parameters

IMPORT_C virtual TPageAbandonFunction AcquireL();

Description

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

Return value

IMPORT_C virtual TAny* AllocL();

Description

Allocates an unassigned page.

Return value

IMPORT_C virtual TAny* LockL(TPageRef aRef);

Description

Locks a page and returns a pointer to it.

Parameters

Return value

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

Description

Assigns a reference to a new page and unlocks it.

Parameters

Return value

IMPORT_C virtual void UpdateL(const TAny *aPage);

Description

Updates a page.

Parameters

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

Description

Unlocks a page.

Parameters

IMPORT_C 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

IMPORT_C void FlushL();

Description

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

IMPORT_C void Purge();

Description

Purge all pages in this pool from the cache.

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

protected: IMPORT_C virtual void DoDeleteL(TPageRef aRef);

Description

Parameters

private: virtual TPageRef ExtendL(const TAny *aPage, TPageReclamation aReclamation)=0;

Description

Parameters

Return value

private: virtual void WriteL(TPageRef aRef, const TAny *aPage, TPageChange aChange)=0;

Description

Parameters

private: virtual void ReadL(TPageRef aRef, TAny *aPage)=0;

Description

Parameters