# NodeCachedReferenceCount

from pandac.PandaModules import NodeCachedReferenceCount

Class : NodeCachedReferenceCount
Description : This class further specializes CachedTypedWritableReferenceCount to also add a node_ref_count, for the purposes of counting the number of times the object is referenced by a "node", presumably a PandaNode.
This essentially combines the functionality of NodeReferenceCount and CachedTypedWritableReferenceCount, so that a derivative of this object actually has three counters: the standard reference count, the "cache" reference count, and the "node" reference count. Rather than multiply inheriting from the two reference count classes, we inherit only from CachedTypedWritableReferenceCount and simply duplicate the functionality of NodeReferenceCount, to avoid all of the problems associated with multiple inheritance.
The intended design is to use this as a base class for RenderState and TransformState, both of which are held by PandaNodes, and also have caches which are independently maintained. By keeping track of how many nodes hold a pointer to a particular object, we can classify each object into node-referenced, cache-referenced, or other, which is primarily useful for PStats reporting.
As with CachedTypedWritableReferenceCount's cache_ref() and cache_unref(), the new methods node_ref() and node_unref() automatically increment and decrement the primary reference count as well. In this case, however, there does exist a NodePointerTo<> class to maintain the node_ref counters automatically.

## Inheritance:

NodeCachedReferenceCount: CachedTypedWritableReferenceCount
CachedTypedWritableReferenceCount: TypedWritableReferenceCount
TypedWritableReferenceCount: TypedWritable ReferenceCount
TypedWritable: TypedObject
TypedObject: MemoryBase
MemoryBase:
ReferenceCount: MemoryBase

## Methods of NodeCachedReferenceCount:

getClassType
getNodeRefCount
getReferencedBits
nodeRef
nodeUnref
testRefCountIntegrity

## Methods of CachedTypedWritableReferenceCount:

cacheRef
cacheUnref
getCacheRefCount
getClassType
testRefCountIntegrity

## Methods of TypedWritableReferenceCount:

getClassType

## Methods of TypedWritable:

getClassType

## Methods of TypedObject:

getClassType
getType
getTypeIndex
isExactType
isOfType

## Methods of ReferenceCount:

getClassType
getRefCount
ref
testRefCountIntegrity
testRefCountNonzero
unref

## Constants in NodeCachedReferenceCount:

RNode | (Referenced)
RCache | (Referenced)

getClassType static TypeHandle NodeCachedReferenceCount::get_class_type(void); Undocumented function.

getNodeRefCount int NodeCachedReferenceCount::get_node_ref_count(void) const; Description: Returns the current reference count.

getReferencedBits int NodeCachedReferenceCount::get_referenced_bits(void) const; Description: Returns the union of the values defined in the Referenced enum that represents the various things that appear to be holding a pointer to this object. If R_node is included, at least one node is holding a pointer; if R_cache is included, at least one cache element is.

nodeRef void NodeCachedReferenceCount::node_ref(void) const; Description: Explicitly increments the reference count. This function is const, even though it changes the object, because generally fiddling with an object's reference count isn't considered part of fiddling with the object. An object might be const in other ways, but we still need to accurately count the number of references to it.

nodeUnref bool NodeCachedReferenceCount::node_unref(void) const; Description: Explicitly decrements the node reference count and the normal reference count simultaneously. The return value is true if the new reference count is nonzero, false if it is zero.

testRefCountIntegrity bool NodeCachedReferenceCount::test_ref_count_integrity(void) const; Description: Does some easy checks to make sure that the reference count isn't completely bogus.

cacheRef void CachedTypedWritableReferenceCount::cache_ref(void) const; Description: Explicitly increments the cache reference count and the normal reference count simultaneously.

cacheUnref bool CachedTypedWritableReferenceCount::cache_unref(void) const; Description: Explicitly decrements the cache reference count and the normal reference count simultaneously. The return value is true if the new reference count is nonzero, false if it is zero.

getCacheRefCount int CachedTypedWritableReferenceCount::get_cache_ref_count(void) const; Description: Returns the current reference count.

getClassType static TypeHandle CachedTypedWritableReferenceCount::get_class_type(void); Undocumented function.

testRefCountIntegrity bool CachedTypedWritableReferenceCount::test_ref_count_integrity(void) const; Description: Does some easy checks to make sure that the reference count isn't completely bogus.

getClassType static TypeHandle TypedWritableReferenceCount::get_class_type(void); Undocumented function.

getClassType static TypeHandle TypedWritable::get_class_type(void); Undocumented function.

getClassType static TypeHandle TypedObject::get_class_type(void); Undocumented function.

getType virtual TypeHandle TypedObject::get_type(void) const = 0; Derived classes should override this function to return get_class_type().

getTypeIndex int TypedObject::get_type_index(void) const; Description: Returns the internal index number associated with this object's TypeHandle, a unique number for each different type. This is equivalent to get_type().get_index().

isExactType bool TypedObject::is_exact_type(TypeHandle handle) const; Description: Returns true if the current object is the indicated type exactly.

isOfType bool TypedObject::is_of_type(TypeHandle handle) const; Description: Returns true if the current object is or derives from the indicated type.

getClassType static TypeHandle ReferenceCount::get_class_type(void); Undocumented function.

getRefCount int ReferenceCount::get_ref_count(void) const; Description: Returns the current reference count.

ref void ReferenceCount::ref(void) const; Description: Explicitly increments the reference count. User code should avoid using ref() and unref() directly, which can result in missed reference counts. Instead, let a PointerTo object manage the reference counting automatically. This function is const, even though it changes the object, because generally fiddling with an object's reference count isn't considered part of fiddling with the object. An object might be const in other ways, but we still need to accurately count the number of references to it.

testRefCountIntegrity bool ReferenceCount::test_ref_count_integrity(void) const; Description: Does some easy checks to make sure that the reference count isn't completely bogus. Returns true if ok, false otherwise.

testRefCountNonzero bool ReferenceCount::test_ref_count_nonzero(void) const; Description: Does some easy checks to make sure that the reference count isn't zero, or completely bogus. Returns true if ok, false otherwise.

unref bool ReferenceCount::unref(void) const; Description: Explicitly decrements the reference count. Note that the object will not be implicitly deleted by unref() simply because the reference count drops to zero. (Having a member function delete itself is problematic; plus, we don't have a virtual destructor anyway.) However, see the helper function unref_delete(). User code should avoid using ref() and unref() directly, which can result in missed reference counts. Instead, let a PointerTo object manage the reference counting automatically. This function is const, even though it changes the object, because generally fiddling with an object's reference count isn't considered part of fiddling with the object. An object might be const in other ways, but we still need to accurately count the number of references to it. The return value is true if the new reference count is nonzero, false if it is zero.