HVD_cache_params Struct Reference

Parameters for the HVD cache instance. More...

#include "hvdcache.h"

Data Fields
size_t	size
	The size of this structure.
const uint8 *	cache_id
	HVD cache ID for this cache.
const uint8 *	setup_id
HVD_cache_policy	cache_policy
	Caching purging policy.
HVD_element_release_fn *	element_release_fn
HVD_raster_release_fn *	raster_release_fn
HVD_recovery_filter_fn *	recovery_filter_fn
HVD_raster_purge_fn *	raster_purge_fn
sw_memory_instance *	mem
	Memory allocation/deallocation functions.

Detailed Description

Parameters for the HVD cache instance.

Field Documentation

element_release_fn

HVD_element_release_fn* HVD_cache_params::element_release_fn

A function to call when an element is destroyed. This is called after destroying all rasters attached to the element.

Parameters

[in]	pElement	The element which the element handle was attached to.
[in]	helement	Data attached to the element using HVD_element_set_data().

raster_purge_fn

HVD_raster_purge_fn* HVD_cache_params::raster_purge_fn

A function to compress or purge data from rasters when running low on cache memory. This is called for each raster attached to an element. If not enough memory can be recovered by purging the top candidate elements, they will be released.

Parameters

[in]	pElement	The element which the raster handle was attached to.
[in]	hraster	A raster handle previously passed to HVD_element_add_raster().
[in,out]	recover	A location where the amount of memory the purge operation still needs to recover is stored. On exit, the raster purge function should update this to the amount that is still needed after compressing, purging to storage, or otherwise reducing memory consumption. The reduction in memory may exceed the amount needed, in which case the raster purge function should set *recover to zero on exit.

Returns

The new size of the raster data after compressing, purging to storage, or otherwise reducing memory consumption.

The purge function, if present, may be called while an element is locked. It must not discard raster data, but may make it slower to access.

raster_release_fn

HVD_raster_release_fn* HVD_cache_params::raster_release_fn

A function to call when an element with attached rasters is destroyed. This is called for each raster attached to the element.

Parameters

[in]	pElement	The element which the raster handle was attached to.
[in]	hraster	A raster handle previously passed to HVD_element_add_raster().

recovery_filter_fn

HVD_recovery_filter_fn* HVD_cache_params::recovery_filter_fn

A function to filter rasters to those suitable for compression or eviction when running low on memory. If this parameter is NULL, then all elements and rasters will be considered eligible for all low memory calls.

Parameters

[in]	pElement	The element that might be removed from the cache.
[in]	reason	The reason supplied to the call to HVD_cache_size() or HVD_cache_recover(). This parameter may be used to exclude elements or rasters from low-memory recovery, if they do not contribute to the type of memory requested.

Return values

TRUE	The HVD raster is eligible for purging or removal.
FALSE	The HVD raster is not eligible for purging or removal.

setup_id

const uint8* HVD_cache_params::setup_id

The setup ID for the cache instance. If this is an empty string, it will not match any existing cache instance. This guarantees that all elements are deleted when the connection is disconnected.

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The documentation for this struct was generated from the following file:

• lib/interface/hvdcache.h