WSGLBufferObjectCache Class Reference

The WSGLBufferObjectCache is a cache which manages the allocation and storage of WSGLBufferObjectCacheItem (cache items). More...

#include <Rendering/OpenGL/wsglbufferobjectcache.h>

Inheritance diagram for WSGLBufferObjectCache:

Classes
struct	CacheItemDiagnosticInfo

Public Types
using	ContentDiagnostics = QMap< QString, CacheItemDiagnosticInfo >

Public Member Functions
	WSGLBufferObjectCache ()
	WSGLBufferObjectCache (const WSGLBufferObjectCache &)=delete
	WSGLBufferObjectCache (size_t capacity)
	~WSGLBufferObjectCache () override
void	discardUnused ()
size_t	getBytesInUse ()
WSGLBufferObjectCacheItemPtr	getCacheItem (const QString &id, QOpenGLBuffer::Type type)
size_t	getCapacity ()
ContentDiagnostics	getContentDiagnostics () const
size_t	getSize ()
bool	hasCacheItem (const QString &id) const
WSGLBufferObjectCache &	operator= (const WSGLBufferObjectCache &)=delete
void	setCapacity (size_t capacity)

Detailed Description

The cache keeps track of each cache item, making sure that unused items are placed onto an expiry queue, ready for deletion. Items that are still in use will never be placed on the queue.

The only way that WSGLBufferObjectCacheItems should be created is via the getCacheItem function. This will return a reference-counted pointer (WSGLBufferObjectCacheItemPtr) to the cache item.

See also

WSGLBufferObjectCacheItem

WSGLBufferObjectCacheItemPtr

Member Typedef Documentation

ContentDiagnostics

using ContentDiagnostics = QMap<QString, CacheItemDiagnosticInfo>

Constructor & Destructor Documentation

WSGLBufferObjectCache() [1/3]

WSGLBufferObjectCache

(

)

Create a cache with no size limit.

WSGLBufferObjectCache() [2/3]

WSGLBufferObjectCache

(

size_t

capacity

)

Create a cache with the specified size limit.

~WSGLBufferObjectCache()

~WSGLBufferObjectCache ( )

override

Must ensure the cache is emptied before deleting it. We must not hold onto any OpenGL buffer objects.

WSGLBufferObjectCache() [3/3]

WSGLBufferObjectCache ( const WSGLBufferObjectCache &  )

delete

Member Function Documentation

discardUnused()

void discardUnused

(

)

Purges any expired items in the cache. The items themselves will manage their own deletion.

getBytesInUse()

size_t getBytesInUse

(

)

Returns the number of bytes that are currently in use (i.e. not on the expiry queue). This can be used to determine whether or not pointers are being held between frames for debug purposes.

Returns

size of the number of items currently held by pointers, in bytes.

getCacheItem()

WSGLBufferObjectCacheItemPtr getCacheItem	(	const QString &	id,
		QOpenGLBuffer::Type	type
	)

Publically accessible function to get an item from the cache. If one does not exist, a new item will be created and added to the cache. In certain situations, the cache item may fail to be created (usually due to an invalid GL context, or no buffer support). If this occurs, an invalid (empty) WSGLBufferObjectCacheItemPtr will be returned.

Parameters

id	The unique identifier of the item to retrieve / create.
type	The GL buffer type of the item. Not used if retrieving an item. Only used when creating.

Returns

pointer object to the Cache Item which will automatically manage the ref counting

getCapacity()

size_t getCapacity

(

)

Returns the capacity of the cache in bytes, AKA its size limit. If the cache is of unlimited capacity, it will return 0.

Returns

the capacity of the cache, in bytes (or 0 of capacity is unlimited)

getContentDiagnostics()

WSGLBufferObjectCache::ContentDiagnostics getContentDiagnostics

(

)

const

Returns

A collection of diagnostics; one for each item in the cache.

getSize()

size_t getSize

(

)

Returns the current size of the cache in bytes, i.e. the total size of all the items that have been added to the cache.

Returns

size of the cache in bytes.

hasCacheItem()

bool hasCacheItem

(

const QString &

id

)

const

Function to check whether or not an item with the specified ID is in the cache.

Parameters

id

Returns

true if an item with the specified id exists in the cache, false otherwise.

operator=()

WSGLBufferObjectCache & operator= ( const WSGLBufferObjectCache &  )

delete

setCapacity()

void setCapacity

(

size_t

capacity

)

Parameters

capacity

The desired capacity of the buffer object cache.

Sets the capacity of the WSGLBufferObjectCache. Note that if the specified capacity is lower than the existing capacity, unused items in the cache will be discarded up-until the size is less than or equal to the new capacity.