#include <Cache.h>

Inheritance diagram for prt::Cache:

Public Types
enum	PersistentBlobType { CACHE_TYPE_IMAGE_METADATA, CACHE_TYPE_PIXELDATA }

Public Member Functions
virtual void	flushAll ()=0

virtual void	flushContentType (ContentType type)=0

virtual void	flushEntry (ContentType type, const wchar_t *key)=0

virtual const void *	getPersistentBlob (PersistentBlobType type, const wchar_t key, size_t size) const =0

virtual const void *	getTransientBlob (ContentType type, const wchar_t *key) const =0

virtual const void *	insertAndGetTransientBlob (ContentType type, const wchar_t key, const void ptr)=0

virtual void	insertPersistentBlobAndLock (PersistentBlobType type, const wchar_t key, const void data, size_t size)=0

virtual void	releasePersistentBlob (PersistentBlobType type, const wchar_t *key)=0

virtual void	releaseTransientBlob (ContentType type, const wchar_t *key)=0

virtual bool	tryLockPersistentBlobs (ContentType type, const wchar_t *key)=0

virtual void	unlockPersistentBlob (PersistentBlobType type, const wchar_t *key)=0

Static Protected Member Functions
static void	deleteTransientBlob (const void *ptr)

Detailed Description

The Cache interface is a callback interface which can be implemented by the client.

Procedural Runtime's internal databackend, which resolves URIs to texture/geometry/cgb/material resources, uses this interface to insert and lookup resolved resources.

A cache entry is identified with a unique string (key), typically an URI. There are two major types of cache entries:

transient: these are non-serializable, prt-internal resources; the data contains a reference to an internal refcount pointer, size is sizeof(void*)
persistent: these are typed, serializable data blocks; some transient resources are an aggregation of datablocks. This allows for
- redundancy removal
- direct insertion of datablocks into the cache from some other source to bypass the resolve step
- lazy-loading of datablocks

Currently, persistent blobs are only implemented for textures. Persistent blobs can be locked and reserved: Locked means the Cache knows the content (and it's guaranteed that a call to getPersistentBlob() succeeds). Reserved means the Cache has the content in memory (and a pointer associated to it).

A number of cache implementations is provided in CacheObject.

See also: CacheObject, prtx::DataBackend

Member Enumeration Documentation

◆ PersistentBlobType

enum prt::Cache::PersistentBlobType

Types of persistent blobs.

Enumerator

CACHE_TYPE_IMAGE_METADATA

  uint32_t  Version             // 3
  uint32_t  MD5Hash[4]          // md5 hash of associated pixeldata
  uint32_t  Width               // width of associated pixeldata
  uint32_t  Height              // height of associated pixedata
  uint32_t  Format              // GREY8 = 1, GREY16 = 2, RGB8 = 3, RGBA8 = 4, FLOAT32 = 5
  double    Offset[3]           // georef: offset per channel (default: 0)
  double    Scale[3]            // georef: scale per channel  (default: 1)
  double    NoDataValue[3]      // georef: no data value markers per channel (default: MAX_DOUBLE)
  char      Unit[32]            // georef: semicolon separated strings per channel (default: empty)
  double    GeoTransform[6]     // georef: see GDALDataset::GetGeoTransform() function of GDAL (default: [0 1 0 0 0 1])
  char      ProjectionRef[1024] // georef: "Well-known text" string describing the spatial reference system (default: empty)

CACHE_TYPE_PIXELDATA

The decoded pixeldata, size = width*height*channels.

Member Function Documentation

◆ deleteTransientBlob()

static void prt::Cache::deleteTransientBlob ( const void * ptr )

staticprotected

Call this to tell Procedural Runtime that the Cache's reference to a transient resource was internally deleted from the cache. This is typically called on flushing an entry or in the Cache's destructor.

Parameters

ptr	the transient blob to release.

◆ flushAll()

virtual void prt::Cache::flushAll ( )

pure virtual

Releases all transient blobs stored in the cache. If a transient blob is not still referenced anywhere else in the Procedural Runtime and references permanent blobs in the cache, the permanent blobs are released from the cache. Is typically called from the client and must be thread-safe.

See also: flushContentType(), flushEntry()

◆ flushContentType()

virtual void prt::Cache::flushContentType ( ContentType type )

pure virtual

Releases all transient blobs of a certain ContentType. If a transient blob is not still referenced anywhere else in the Procedural Runtime and references permanent blobs in the cache, the permanent blobs are released from the cache. Is typically called from the client and must be thread-safe.

See also: flushAll(), flushEntry()

Parameters

type	Type of the resource.

◆ flushEntry()

virtual void prt::Cache::flushEntry	(	ContentType	type,
		const wchar_t *	key
	)

pure virtual

Releases one specific transient blob from the cache. If a transient blob is not still referenced anywhere else in the Procedural Runtime and references permanent blobs in the cache, the permanent blobs are released from the cache. Is typically called from the client and must be thread-safe.

See also: flushAll(), flushContentType()

Parameters

type	Type of the resource.
key	Unique string to identify the resource.

◆ getPersistentBlob()

virtual const void* prt::Cache::getPersistentBlob	(	PersistentBlobType	type,
		const wchar_t *	key,
		size_t *	size
	)		const

pure virtual

Gets the pointer to a (locked) persistent blob plus its size. The pointer is guaranteed to stay valid ("reserved") until releasePersistentBlob() is called.

If (type, key) does not refer to a previously locked blob the behaviour is undefined.

Parameters

	type	Type of the resource.
	key	Unique string to identify the resource.
[out]	size	Pointer to return the blob size in bytes.

Returns: Pointer to the persistent blob.

◆ getTransientBlob()

virtual const void* prt::Cache::getTransientBlob	(	ContentType	type,
		const wchar_t *	key
	)		const

pure virtual

If a pointer is returned: is guaranteed to stay valid until releaseTransientBlob() is called. releaseTransientBlob() must be called when the pointer is not used anymore.

Parameters

type	Type of the resource.
key	Unique string to identify the resource.

Returns: The transient resource if known, 0 otherwise.

◆ insertAndGetTransientBlob()

virtual const void* prt::Cache::insertAndGetTransientBlob	(	ContentType	type,
		const wchar_t *	key,
		const void *	ptr
	)

pure virtual

Inserts a transient blob and returns an equivalent transient blob. This can, but doesn't need to, be the inserted blob. The returned blob is guaranteed to stay valid until releaseTransientBlob() is called. releaseTransientBlob() must be called when the returned pointer is not used anymore. If the return value is different than the passed-in ptr, ptr was not inserted into and will not be used by the cache.

Parameters

type	Type of the resource.
key	Unique string to identify the resource.
ptr	Pointer to a transient resource,

Returns: ptr or another, previously inserted pointer to a transient resource with identical permanent blob layout.

◆ insertPersistentBlobAndLock()

virtual void prt::Cache::insertPersistentBlobAndLock	(	PersistentBlobType	type,
		const wchar_t *	key,
		const void *	data,
		size_t	size
	)

pure virtual

Inserts a persistent data blob connected to a key and locks it.

Parameters

type	Type of the resource.
key	Unique string to identify the resource.
data	Pointer to data to insert.
size	Size of data to insert in bytes.

◆ releasePersistentBlob()

virtual void prt::Cache::releasePersistentBlob	(	PersistentBlobType	type,
		const wchar_t *	key
	)

pure virtual

Releases the pointer assigned to a persistent blob.

Parameters

type	Type of the resource.
key	Unique string to identify the resource.

◆ releaseTransientBlob()

virtual void prt::Cache::releaseTransientBlob	(	ContentType	type,
		const wchar_t *	key
	)

pure virtual

Releases a previously locked transient blob.

Parameters

type	Type of the resource.
key	Unique string to identify the resource.

◆ tryLockPersistentBlobs()

virtual bool prt::Cache::tryLockPersistentBlobs	(	ContentType	type,
		const wchar_t *	key
	)

pure virtual

Tries to lock all persistent blobs associated with a (transient) key. If the layout + the permanent blobs are known to the cache, they are locked (i.e. prevented from being deleted from permanent storage).

Parameters

type	Type of the resource.
key	Unique string to identify the resource.

Returns: true if the permanent blobs are known, else false.

◆ unlockPersistentBlob()

virtual void prt::Cache::unlockPersistentBlob	(	PersistentBlobType	type,
		const wchar_t *	key
	)

pure virtual

Unlocks a persistent blob. Unlocked blobs can be deleted from persistent storage, reserved pointers stay valid however.

Parameters

type	Type of the resource.
key	Unique string to identify the resource.

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

Cache.h

Public Types

Public Member Functions

Static Protected Member Functions

Detailed Description

Member Enumeration Documentation

◆ PersistentBlobType

Member Function Documentation

◆ deleteTransientBlob()

◆ flushAll()

◆ flushContentType()

◆ flushEntry()

◆ getPersistentBlob()

◆ getTransientBlob()

◆ insertAndGetTransientBlob()

◆ insertPersistentBlobAndLock()

◆ releasePersistentBlob()

◆ releaseTransientBlob()

◆ tryLockPersistentBlobs()

◆ unlockPersistentBlob()