GRK/dependencies/physx-4.1/source/foundation/include/PsHashSet.h

128 lines
4.7 KiB
C
Raw Normal View History

2022-01-12 16:07:16 +01:00
//
// 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_PSHASHSET_H
#define PSFOUNDATION_PSHASHSET_H
#include "PsHashInternals.h"
// TODO: make this doxy-format
// This header defines two hash sets. Hash sets
// * 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
//
// Sets have STL-like copying semantics, and properly initialize and destruct copies of objects
//
// There are two forms of set: coalesced and uncoalesced. Coalesced sets keep the entries in the
// initial segment of an array, so are fast to iterate over; however deletion is approximately
// twice as expensive.
//
// HashSet<T>:
// bool insert(const T& k) amortized O(1) (exponential resize policy)
// bool contains(const T& k) const; O(1)
// bool erase(const T& k); O(1)
// uint32_t size() const; constant
// void reserve(uint32_t size); O(MAX(size, currentOccupancy))
// void clear(); O(currentOccupancy) (with zero constant for objects without
// destructors)
// Iterator getIterator();
//
// Use of iterators:
//
// for(HashSet::Iterator iter = test.getIterator(); !iter.done(); ++iter)
// myFunction(*iter);
//
// CoalescedHashSet<T> does not support getIterator, but instead supports
// const Key *getEntries();
//
// insertion into a set already containing the element fails returning false, as does
// erasure of an element not in the set
//
namespace physx
{
namespace shdfnd
{
template <class Key, class HashFn = Hash<Key>, class Allocator = NonTrackingAllocator>
class HashSet : public internal::HashSetBase<Key, HashFn, Allocator, false>
{
public:
typedef internal::HashSetBase<Key, HashFn, Allocator, false> HashSetBase;
typedef typename HashSetBase::Iterator Iterator;
HashSet(uint32_t initialTableSize = 64, float loadFactor = 0.75f) : HashSetBase(initialTableSize, loadFactor)
{
}
HashSet(uint32_t initialTableSize, float loadFactor, const Allocator& alloc)
: HashSetBase(initialTableSize, loadFactor, alloc)
{
}
HashSet(const Allocator& alloc) : HashSetBase(64, 0.75f, alloc)
{
}
Iterator getIterator()
{
return Iterator(HashSetBase::mBase);
}
};
template <class Key, class HashFn = Hash<Key>, class Allocator = NonTrackingAllocator>
class CoalescedHashSet : public internal::HashSetBase<Key, HashFn, Allocator, true>
{
public:
typedef typename internal::HashSetBase<Key, HashFn, Allocator, true> HashSetBase;
CoalescedHashSet(uint32_t initialTableSize = 64, float loadFactor = 0.75f)
: HashSetBase(initialTableSize, loadFactor)
{
}
CoalescedHashSet(uint32_t initialTableSize, float loadFactor, const Allocator& alloc)
: HashSetBase(initialTableSize, loadFactor, alloc)
{
}
CoalescedHashSet(const Allocator& alloc) : HashSetBase(64, 0.75f, alloc)
{
}
const Key* getEntries() const
{
return HashSetBase::mBase.getEntries();
}
};
} // namespace shdfnd
} // namespace physx
#endif // #ifndef PSFOUNDATION_PSHASHSET_H