The Nebula Device 3: Resources::ResourceManager Class Reference

The Nebula Device 3

Resources::ResourceManager Class Reference

#include <resourcemanager.h>

Inheritance diagram for Resources::ResourceManager:

Core::RefCounted


Detailed Description

The ResourceManager adds a management layer between resource using clients and actual resource objects. The main purpose of the manager is resource streaming for large seamless worlds. Resource users request a ManagedResource object from the ResourceManager. A ManagedResource is a wrapper around an actual Resource object, which may change based on the resource management strategy implemented by the manager. The main job of a resource manager is to provide all the resource required for rendering while making the best use of limited resource memory. It will also care about background loading of resources, and provide placeholder resources if a resource hasn't finished loading.

The actual resource management strategies for different resource types are customizable by attaching ResourceMapper objects to the ResourceManager. A ResourceMapper analyzes the usage statistics of existing ManagedResource objects and implements a specific resource management pattern using the following basic operations:

  • Load(pri, lod): asynchronously load a resource from external storage into memory given a priority and a level-of-detail.
  • Discard: completely unload a resource, freeing up limited resource memory.
  • Upgrade(lod): upgrade a loaded resource to a higher level-of-detail
  • Degrade(lod): degrade a loaded resource to a lower level-of-detail

(C) 2007 Radon Labs GmbH

Public Member Functions

 ResourceManager ()
 constructor
virtual ~ResourceManager ()
 destructor
void Open ()
 open the resource manager
void Close ()
 close the resource manager
bool IsOpen () const
 return true if resource manager is open
void AttachMapper (const Ptr< ResourceMapper > &mapper)
 register a resource mapper (resource type is defined by mapper)
void RemoveMapper (const Core::Rtti &resourceType)
 unregister a resource mapper by resource type
void RemoveAllMappers ()
 unregister all mappers
bool HasMapper (const Core::Rtti &resourceType) const
 return true if a mapper has been registered for the given resource type
const Ptr
< ResourceMapper > & 
GetMapperByResourceType (const Core::Rtti &resourceType) const
 get the resource mapper registered with a resource type
Ptr< ManagedResourceCreateManagedResource (const Core::Rtti &resType, const ResourceId &id)
 create a ManagedResource object (bumps usecount on existing resource)
void DiscardManagedResource (const Ptr< ManagedResource > &managedResource)
 unregister a ManagedResource object
bool HasManagedResource (const ResourceId &id) const
 return true if a managed resource exists
const Ptr
< ManagedResource > & 
LookupManagedResource (const ResourceId &id) const
 lookup a managed resource (does not change usecount of resource)
void Prepare ()
 prepare stats gathering, call per frame
void Update ()
 perform actual resource management, call per frame
int GetRefCount () const
 get the current refcount
void AddRef ()
 increment refcount by one
void Release ()
 decrement refcount and destroy object if refcount is zero
bool IsInstanceOf (const Rtti &rtti) const
 return true if this object is instance of given class
bool IsInstanceOf (const Util::String &className) const
 return true if this object is instance of given class by string
bool IsInstanceOf (const Util::FourCC &classFourCC) const
 return true if this object is instance of given class by fourcc
bool IsA (const Rtti &rtti) const
 return true if this object is instance of given class, or a derived class
bool IsA (const Util::String &rttiName) const
 return true if this object is instance of given class, or a derived class, by string
bool IsA (const Util::FourCC &rttiFourCC) const
 return true if this object is instance of given class, or a derived class, by fourcc
const Util::StringGetClassName () const
 get the class name
Util::FourCC GetClassFourCC () const
 get the class FourCC code

Static Public Member Functions

static void DumpRefCountingLeaks ()
 dump refcounting leaks, call at end of application (NEBULA3_DEBUG builds only!)

Member Function Documentation

Ptr< ManagedResource > Resources::ResourceManager::CreateManagedResource ( const Core::Rtti resType,
const ResourceId resId 
)

create a ManagedResource object (bumps usecount on existing resource)

Create a shared ResourceManager object. If a managed resource with the same resource name already exists, its client count will be incremented and it will be returned. Otherwise the right ResourceMapper will be asked to create a new managed resource.

void Resources::ResourceManager::DiscardManagedResource ( const Ptr< ManagedResource > &  managedResource  ) 

unregister a ManagedResource object

Discard a shared ManagedResource object. This will decrement the client count. If the client count reaches zero, the ManagedResource object will be released as well.

void Resources::ResourceManager::Prepare (  ) 

prepare stats gathering, call per frame

This method must be called per-frame before rendering begins. This will call the OnPrepare() method on all attached resource mappers, which will at least reset the render statistics in the managed resource.

void Resources::ResourceManager::Update (  ) 

perform actual resource management, call per frame

This method must be called by the application after render statistics have been gathered and before the actual rendering. The ResourceManager will call the OnUpdate() method on all attached resource mappers. This is the place where the actual resource management will happen.

int Core::RefCounted::GetRefCount (  )  const [inline, inherited]

get the current refcount

Return the current refcount of the object.

void Core::RefCounted::AddRef (  )  [inline, inherited]

increment refcount by one

Increment the refcount of the object.

void Core::RefCounted::Release (  )  [inline, inherited]

decrement refcount and destroy object if refcount is zero

Decrement the refcount and destroy object if refcount is zero.

const Util::String & Core::RefCounted::GetClassName (  )  const [inline, inherited]

get the class name

Get the class name of the object.

Util::FourCC Core::RefCounted::GetClassFourCC (  )  const [inline, inherited]

get the class FourCC code

Get the class FourCC of the object.

void Core::RefCounted::DumpRefCountingLeaks (  )  [static, inherited]

dump refcounting leaks, call at end of application (NEBULA3_DEBUG builds only!)

This method should be called as the very last before an application exits.