Projekt_Grafika/dependencies/physx-4.1/source/foundation/include/PsHashMap.h

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//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of NVIDIA CORPORATION nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Copyright (c) 2008-2019 NVIDIA Corporation. All rights reserved.
// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.
#ifndef PSFOUNDATION_PSHASHMAP_H
#define PSFOUNDATION_PSHASHMAP_H
#include "PsHashInternals.h"
// TODO: make this doxy-format
//
// This header defines two hash maps. Hash maps
// * support custom initial table sizes (rounded up internally to power-of-2)
// * support custom static allocator objects
// * auto-resize, based on a load factor (i.e. a 64-entry .75 load factor hash will resize
// when the 49th element is inserted)
// * are based on open hashing
// * have O(1) contains, erase
//
// Maps have STL-like copying semantics, and properly initialize and destruct copies of objects
//
// There are two forms of map: coalesced and uncoalesced. Coalesced maps keep the entries in the
// initial segment of an array, so are fast to iterate over; however deletion is approximately
// twice as expensive.
//
// HashMap<T>:
// bool insert(const Key& k, const Value& v) O(1) amortized (exponential resize policy)
// Value & operator[](const Key& k) O(1) for existing objects, else O(1) amortized
// const Entry * find(const Key& k); O(1)
// bool erase(const T& k); O(1)
// uint32_t size(); constant
// void reserve(uint32_t size); O(MAX(currentOccupancy,size))
// void clear(); O(currentOccupancy) (with zero constant for objects
// without
// destructors)
// Iterator getIterator();
//
// operator[] creates an entry if one does not exist, initializing with the default constructor.
// CoalescedHashMap<T> does not support getIterator, but instead supports
// const Key *getEntries();
//
// Use of iterators:
//
// for(HashMap::Iterator iter = test.getIterator(); !iter.done(); ++iter)
// myFunction(iter->first, iter->second);
namespace physx
{
namespace shdfnd
{
template <class Key, class Value, class HashFn = Hash<Key>, class Allocator = NonTrackingAllocator>
class HashMap : public internal::HashMapBase<Key, Value, HashFn, Allocator>
{
public:
typedef internal::HashMapBase<Key, Value, HashFn, Allocator> HashMapBase;
typedef typename HashMapBase::Iterator Iterator;
HashMap(uint32_t initialTableSize = 64, float loadFactor = 0.75f) : HashMapBase(initialTableSize, loadFactor)
{
}
HashMap(uint32_t initialTableSize, float loadFactor, const Allocator& alloc)
: HashMapBase(initialTableSize, loadFactor, alloc)
{
}
HashMap(const Allocator& alloc) : HashMapBase(64, 0.75f, alloc)
{
}
Iterator getIterator()
{
return Iterator(HashMapBase::mBase);
}
};
template <class Key, class Value, class HashFn = Hash<Key>, class Allocator = NonTrackingAllocator>
class CoalescedHashMap : public internal::HashMapBase<Key, Value, HashFn, Allocator>
{
public:
typedef internal::HashMapBase<Key, Value, HashFn, Allocator> HashMapBase;
CoalescedHashMap(uint32_t initialTableSize = 64, float loadFactor = 0.75f)
: HashMapBase(initialTableSize, loadFactor)
{
}
const Pair<const Key, Value>* getEntries() const
{
return HashMapBase::mBase.getEntries();
}
};
} // namespace shdfnd
} // namespace physx
#endif // #ifndef PSFOUNDATION_PSHASHMAP_H