csgo-2018-source/public/tier1/utlbidirectionalset.h
2021-07-24 21:11:47 -07:00

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C++

//========= Copyright © 1996-2005, Valve Corporation, All rights reserved. ============//
//
// Purpose: Bi-directional set. A Bucket knows about the elements that lie
// in it, and the elements know about the buckets they lie in.
//
// $Revision: $
// $NoKeywords: $
//=============================================================================//
#ifndef UTLBIDIRECTIONALSET_H
#define UTLBIDIRECTIONALSET_H
#ifdef _WIN32
#pragma once
#endif
#include "tier0/dbg.h"
#include "utllinkedlist.h"
//-----------------------------------------------------------------------------
// Templatized helper class to deal with the kinds of things that spatial
// partition code always seems to have; buckets with lists of lots of elements
// and elements that live in lots of buckets. This makes it really quick to
// add and remove elements, and to iterate over all elements in a bucket.
//
// For this to work, you must initialize the set with two functions one that
// maps from bucket to the index of the first element in that bucket, and one
// that maps from element to the index of the first bucket that element lies in.
// The set will completely manage the index, it's just expected that those
// indices will be stored outside the set.
//
// S is the storage type of the index; it is the type that you may use to
// save indices into memory. I is the local iterator type, which you should
// use in any local scope (eg, inside a for() loop.) The reason for this is
// that you may wish to use unsigned shorts inside the structs you are
// saving with a CBidirectionalSet; but 16-bit arithmetic is catastrophically
// slow on a PowerPC -- during testing we saw CBidirectionalSet:: operations
// consume as much as 8% of the frame.
//
// For this reason, on the 360, the handles have been typedef'd to native
// register types (U32) which are accepted as parameters by the functions.
// The implicit assumption is that CBucketHandle and CElementHandle can
// be safely cast to ints! You can increase to U64 without performance
// penalty if necessary; the PowerPC is a 64-bit processor.
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I = S >
class CBidirectionalSet
{
public:
// Install methods to get at the first bucket given a element
// and vice versa...
typedef S& (*FirstElementFunc_t)(CBucketHandle);
typedef S& (*FirstBucketFunc_t)(CElementHandle);
#ifdef _X360
typedef uint32 CBucketHandlePram;
typedef uint32 CElementHandlePram;
#else
typedef CBucketHandle CBucketHandlePram;
typedef CElementHandle CElementHandlePram;
#endif
// Constructor
CBidirectionalSet();
// Call this before using the set
void Init( FirstElementFunc_t elemFunc, FirstBucketFunc_t bucketFunc );
// Add an element to a particular bucket
void AddElementToBucket( CBucketHandlePram bucket, CElementHandlePram element );
// Prevalidate an add to a particular bucket
// NOTE: EXPENSIVE!!!
void ValidateAddElementToBucket( CBucketHandlePram bucket, CElementHandlePram element );
// Test if an element is in a particular bucket.
// NOTE: EXPENSIVE!!!
bool IsElementInBucket( CBucketHandlePram bucket, CElementHandlePram element );
// Remove an element from a particular bucket
void RemoveElementFromBucket( CBucketHandlePram bucket, CElementHandlePram element );
// Remove an element from all buckets
void RemoveElement( CElementHandlePram element );
void RemoveBucket( CBucketHandlePram element );
// Used to iterate elements in a bucket; I is the iterator
I FirstElement( CBucketHandlePram bucket ) const;
I NextElement( I idx ) const;
CElementHandle Element( I idx ) const;
// Used to iterate buckets associated with an element; I is the iterator
I FirstBucket( CElementHandlePram bucket ) const;
I NextBucket( I idx ) const;
CBucketHandle Bucket( I idx ) const;
static S InvalidIndex();
// Ensure capacity
void EnsureCapacity( int count );
// Deallocate....
void Purge();
int NumAllocated( void ) const;
private:
struct BucketListInfo_t
{
CElementHandle m_Element;
S m_BucketListIndex; // what's the m_BucketsUsedByElement index of the entry?
};
struct ElementListInfo_t
{
CBucketHandle m_Bucket;
S m_ElementListIndex; // what's the m_ElementsInBucket index of the entry?
};
// Maintains a list of all elements in a particular bucket
CUtlLinkedList< BucketListInfo_t, S, true, I > m_ElementsInBucket;
// Maintains a list of all buckets a particular element lives in
CUtlLinkedList< ElementListInfo_t, S, true, I > m_BucketsUsedByElement;
FirstBucketFunc_t m_FirstBucket;
FirstElementFunc_t m_FirstElement;
};
//-----------------------------------------------------------------------------
// Constructor
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::CBidirectionalSet( )
{
m_FirstBucket = NULL;
m_FirstElement = NULL;
}
//-----------------------------------------------------------------------------
// Call this before using the set
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
void CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::Init( FirstElementFunc_t elemFunc, FirstBucketFunc_t bucketFunc )
{
m_FirstBucket = bucketFunc;
m_FirstElement = elemFunc;
}
//-----------------------------------------------------------------------------
// Adds an element to the bucket
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
void CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::ValidateAddElementToBucket( CBucketHandlePram bucket, CElementHandlePram element )
{
#ifdef _DEBUG
// Make sure that this element doesn't already exist in the list of elements in the bucket
I elementInBucket = m_FirstElement( bucket );
while( elementInBucket != m_ElementsInBucket.InvalidIndex() )
{
// If you hit an Assert here, fix the calling code. It's too expensive to ensure
// that each item only shows up once here. Hopefully you can do something better
// outside of here.
Assert( m_ElementsInBucket[elementInBucket].m_Element != element );
elementInBucket = m_ElementsInBucket.Next( elementInBucket );
}
// Make sure that this bucket doesn't already exist in the element's list of buckets.
I bucketInElement = m_FirstBucket( element );
while( bucketInElement != m_BucketsUsedByElement.InvalidIndex() )
{
// If you hit an Assert here, fix the calling code. It's too expensive to ensure
// that each item only shows up once here. Hopefully you can do something better
// outside of here.
Assert( m_BucketsUsedByElement[bucketInElement].m_Bucket != bucket );
bucketInElement = m_BucketsUsedByElement.Next( bucketInElement );
}
#endif
}
//-----------------------------------------------------------------------------
// Adds an element to the bucket
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
void CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::AddElementToBucket( CBucketHandlePram bucket, CElementHandlePram element )
{
Assert( m_FirstBucket && m_FirstElement );
// Allocate new element + bucket entries
I idx = m_ElementsInBucket.Alloc(true);
I list = m_BucketsUsedByElement.Alloc( true );
// Store off the element data
m_ElementsInBucket[idx].m_Element = element;
m_ElementsInBucket[idx].m_BucketListIndex = list;
// Here's the bucket data
m_BucketsUsedByElement[list].m_Bucket = bucket;
m_BucketsUsedByElement[list].m_ElementListIndex = idx;
// Insert the element into the list of elements in the bucket
S& firstElementInBucket = m_FirstElement( bucket );
if ( firstElementInBucket != m_ElementsInBucket.InvalidIndex() )
m_ElementsInBucket.LinkBefore( firstElementInBucket, idx );
firstElementInBucket = idx;
// Insert the bucket into the element's list of buckets
S& firstBucketInElement = m_FirstBucket( element );
if ( firstBucketInElement != m_BucketsUsedByElement.InvalidIndex() )
m_BucketsUsedByElement.LinkBefore( firstBucketInElement, list );
firstBucketInElement = list;
}
//-----------------------------------------------------------------------------
// Test if an element is in a particular bucket.
// NOTE: EXPENSIVE!!!
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
bool CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::IsElementInBucket( CBucketHandlePram bucket, CElementHandlePram element )
{
// Search through all elements in this bucket to see if element is in there.
I elementInBucket = m_FirstElement( bucket );
while( elementInBucket != m_ElementsInBucket.InvalidIndex() )
{
if( m_ElementsInBucket[elementInBucket].m_Element == element )
{
return true;
}
elementInBucket = m_ElementsInBucket.Next( elementInBucket );
}
return false;
}
//-----------------------------------------------------------------------------
// Remove an element from a particular bucket
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
void CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::RemoveElementFromBucket( CBucketHandlePram bucket, CElementHandlePram element )
{
// FIXME: Implement me!
Assert(0);
}
//-----------------------------------------------------------------------------
// Removes an element from all buckets
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
void CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::RemoveElement( CElementHandlePram element )
{
Assert( m_FirstBucket && m_FirstElement );
// Iterate over the list of all buckets the element is in
I i = m_FirstBucket( element );
while (i != m_BucketsUsedByElement.InvalidIndex())
{
CBucketHandlePram bucket = m_BucketsUsedByElement[i].m_Bucket;
I elementListIndex = m_BucketsUsedByElement[i].m_ElementListIndex;
// Unhook the element from the bucket's list of elements
if (elementListIndex == m_FirstElement(bucket))
m_FirstElement(bucket) = m_ElementsInBucket.Next(elementListIndex);
m_ElementsInBucket.Free(elementListIndex);
I prevNode = i;
i = m_BucketsUsedByElement.Next(i);
m_BucketsUsedByElement.Free(prevNode);
}
// Mark the list as empty
m_FirstBucket( element ) = m_BucketsUsedByElement.InvalidIndex();
}
//-----------------------------------------------------------------------------
// Removes a bucket from all elements
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
void CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::RemoveBucket( CBucketHandlePram bucket )
{
// Iterate over the list of all elements in the bucket
I i = m_FirstElement( bucket );
while (i != m_ElementsInBucket.InvalidIndex())
{
CElementHandlePram element = m_ElementsInBucket[i].m_Element;
I bucketListIndex = m_ElementsInBucket[i].m_BucketListIndex;
// Unhook the bucket from the element's list of buckets
if (bucketListIndex == m_FirstBucket(element))
m_FirstBucket(element) = m_BucketsUsedByElement.Next(bucketListIndex);
m_BucketsUsedByElement.Free(bucketListIndex);
// Remove the list element
I prevNode = i;
i = m_ElementsInBucket.Next(i);
m_ElementsInBucket.Free(prevNode);
}
// Mark the bucket list as empty
m_FirstElement( bucket ) = m_ElementsInBucket.InvalidIndex();
}
//-----------------------------------------------------------------------------
// Ensure capacity
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
void CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::EnsureCapacity( int count )
{
m_ElementsInBucket.EnsureCapacity( count );
m_BucketsUsedByElement.EnsureCapacity( count );
}
//-----------------------------------------------------------------------------
// Deallocate....
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
void CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::Purge()
{
m_ElementsInBucket.Purge( );
m_BucketsUsedByElement.Purge( );
}
//-----------------------------------------------------------------------------
// Number of elements allocated in each linked list (should be the same)
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
int CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::NumAllocated( void ) const
{
Assert( m_ElementsInBucket.NumAllocated() == m_BucketsUsedByElement.NumAllocated() );
return m_ElementsInBucket.NumAllocated();
}
//-----------------------------------------------------------------------------
// Invalid index for iteration..
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
inline S CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::InvalidIndex()
{
return CUtlLinkedList< CElementHandle, I >::InvalidIndex();
}
//-----------------------------------------------------------------------------
// Used to iterate elements in a bucket; I is the iterator
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
inline I CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::FirstElement( CBucketHandlePram bucket ) const
{
Assert( m_FirstElement );
return m_FirstElement(bucket);
}
template< class CBucketHandle, class CElementHandle, class S, class I >
inline I CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::NextElement( I idx ) const
{
return m_ElementsInBucket.Next(idx);
}
template< class CBucketHandle, class CElementHandle, class S, class I >
inline CElementHandle CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::Element( I idx ) const
{
return m_ElementsInBucket[idx].m_Element;
}
//-----------------------------------------------------------------------------
// Used to iterate buckets an element lies in; I is the iterator
//-----------------------------------------------------------------------------
template< class CBucketHandle, class CElementHandle, class S, class I >
inline I CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::FirstBucket( CElementHandlePram element ) const
{
Assert( m_FirstBucket );
return m_FirstBucket(element);
}
template< class CBucketHandle, class CElementHandle, class S, class I >
inline I CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::NextBucket( I idx ) const
{
return m_BucketsUsedByElement.Next(idx);
}
template< class CBucketHandle, class CElementHandle, class S, class I >
inline CBucketHandle CBidirectionalSet<CBucketHandle,CElementHandle,S,I>::Bucket( I idx ) const
{
return m_BucketsUsedByElement[idx].m_Bucket;
}
#endif // UTLBIDIRECTIONALSET_H