Override Rack's Message class for prealloc is on stack, not on heap
Signed-off-by: falkTX <falktx@falktx.com>
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falkTX
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528
include/choc/choc_SmallVector.h
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528
include/choc/choc_SmallVector.h
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//
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// ██████ ██ ██ ██████ ██████
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// ██ ██ ██ ██ ██ ██ ** Clean Header-Only Classes **
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// ██ ███████ ██ ██ ██
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// ██ ██ ██ ██ ██ ██ https://github.com/Tracktion/choc
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// ██████ ██ ██ ██████ ██████
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//
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// CHOC is (C)2021 Tracktion Corporation, and is offered under the terms of the ISC license:
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//
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// Permission to use, copy, modify, and/or distribute this software for any purpose with or
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// without fee is hereby granted, provided that the above copyright notice and this permission
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// notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
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// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
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// CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
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// WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
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// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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#ifndef CHOC_SMALLVECTOR_HEADER_INCLUDED
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#define CHOC_SMALLVECTOR_HEADER_INCLUDED
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#include <algorithm>
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#include "choc_Span.h"
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namespace choc
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{
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/**
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A std::vector-style container class, which uses some pre-allocated storage
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to avoid heap allocation when the number of elements is small.
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Inspired by LLVM's SmallVector, I've found this to be handy in many situations
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where you know there's only likely to be a small or fixed number of elements,
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and where performance is important.
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It retains most of the same basic methods as std::vector, but without some of
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the more exotic tricks that the std library uses, just to avoid things getting
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too complicated.
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*/
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template <typename ElementType, size_t numPreallocatedElements>
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struct SmallVector
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{
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using value_type = ElementType;
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using reference = ElementType&;
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using const_reference = const ElementType&;
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using iterator = ElementType*;
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using const_iterator = const ElementType*;
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using size_type = size_t;
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SmallVector() noexcept;
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~SmallVector() noexcept;
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SmallVector (SmallVector&&) noexcept;
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SmallVector (const SmallVector&);
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SmallVector& operator= (SmallVector&&) noexcept;
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SmallVector& operator= (const SmallVector&);
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/// Creates a SmallVector as a copy of some kind of iterable container.
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template <typename VectorType>
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SmallVector (const VectorType& initialContent);
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/// Replaces the contents of this vector with a copy of some kind of iterable container.
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template <typename VectorType>
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SmallVector& operator= (const VectorType&);
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reference operator[] (size_type index);
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const_reference operator[] (size_type index) const;
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value_type* data() const noexcept;
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const_iterator begin() const noexcept;
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const_iterator end() const noexcept;
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const_iterator cbegin() const noexcept;
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const_iterator cend() const noexcept;
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iterator begin() noexcept;
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iterator end() noexcept;
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const_reference front() const;
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reference front();
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const_reference back() const;
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reference back();
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bool empty() const noexcept;
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size_type size() const noexcept;
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size_type length() const noexcept;
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size_type capacity() const noexcept;
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bool contains (const ElementType&) const;
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void clear() noexcept;
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void resize (size_type newSize);
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void reserve (size_type requiredNumElements);
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void push_back (const value_type&);
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void push_back (value_type&&);
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/// Handy method to add multiple elements with a single push_back call.
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template <typename... Others>
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void push_back (const value_type& first, Others&&... others);
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template <typename... ConstructorArgs>
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void emplace_back (ConstructorArgs&&... args);
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void pop_back();
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void insert (iterator insertPosition, const value_type& valueToInsert);
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void insert (iterator insertPosition, value_type&& valueToInsert);
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void erase (iterator startPosition);
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void erase (iterator startPosition, iterator endPosition);
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bool operator== (span<value_type>) const;
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bool operator!= (span<value_type>) const;
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private:
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value_type* elements;
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size_type numElements = 0, numAllocated = numPreallocatedElements;
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uint64_t internalStorage[(numPreallocatedElements * sizeof (value_type) + sizeof (uint64_t) - 1) / sizeof (uint64_t)];
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void shrink (size_type);
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value_type* getInternalStorage() noexcept { return reinterpret_cast<value_type*> (internalStorage); }
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bool isUsingInternalStorage() const noexcept { return numAllocated <= numPreallocatedElements; }
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void resetToInternalStorage() noexcept;
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void freeHeapAndResetToInternalStorage() noexcept;
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static inline ElementType& _nullValue() noexcept { static ElementType e = {}; return e; }
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};
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//==============================================================================
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// _ _ _ _
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// __| | ___ | |_ __ _ (_)| | ___
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// / _` | / _ \| __| / _` || || |/ __|
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// | (_| || __/| |_ | (_| || || |\__ \ _ _ _
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// \__,_| \___| \__| \__,_||_||_||___/(_)(_)(_)
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//
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// Code beyond this point is implementation detail...
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//
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//==============================================================================
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template <typename ElementType, size_t preSize>
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SmallVector<ElementType, preSize>::SmallVector() noexcept : elements (getInternalStorage())
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{
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}
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template <typename ElementType, size_t preSize>
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SmallVector<ElementType, preSize>::~SmallVector() noexcept
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{
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clear();
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}
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template <typename ElementType, size_t preSize>
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SmallVector<ElementType, preSize>::SmallVector (const SmallVector& other) : SmallVector()
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{
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operator= (other);
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}
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template <typename ElementType, size_t preSize>
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template <typename VectorType>
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SmallVector<ElementType, preSize>::SmallVector (const VectorType& initialContent) : SmallVector()
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{
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reserve (initialContent.size());
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for (auto& i : initialContent)
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emplace_back (i);
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}
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template <typename ElementType, size_t preSize>
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SmallVector<ElementType, preSize>::SmallVector (SmallVector&& other) noexcept
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{
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if (other.isUsingInternalStorage())
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{
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elements = getInternalStorage();
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numElements = other.numElements;
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for (size_type i = 0; i < numElements; ++i)
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new (elements + i) value_type (std::move (other.elements[i]));
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}
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else
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{
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elements = other.elements;
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numElements = other.numElements;
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numAllocated = other.numAllocated;
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other.resetToInternalStorage();
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other.numElements = 0;
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}
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}
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template <typename ElementType, size_t preSize>
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SmallVector<ElementType, preSize>& SmallVector<ElementType, preSize>::operator= (SmallVector&& other) noexcept
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{
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clear();
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if (other.isUsingInternalStorage())
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{
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numElements = other.numElements;
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for (size_type i = 0; i < numElements; ++i)
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new (elements + i) value_type (std::move (other.elements[i]));
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}
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else
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{
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elements = other.elements;
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numElements = other.numElements;
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numAllocated = other.numAllocated;
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other.resetToInternalStorage();
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other.numElements = 0;
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}
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return *this;
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}
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template <typename ElementType, size_t preSize>
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SmallVector<ElementType, preSize>& SmallVector<ElementType, preSize>::operator= (const SmallVector& other)
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{
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if (other.size() > numElements)
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{
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reserve (other.size());
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for (size_type i = 0; i < numElements; ++i)
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elements[i] = other.elements[i];
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for (size_type i = numElements; i < other.size(); ++i)
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new (elements + i) value_type (other.elements[i]);
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numElements = other.size();
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}
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else
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{
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shrink (other.size());
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for (size_type i = 0; i < numElements; ++i)
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elements[i] = other.elements[i];
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}
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return *this;
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}
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template <typename ElementType, size_t preSize>
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template <typename VectorType>
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SmallVector<ElementType, preSize>& SmallVector<ElementType, preSize>::operator= (const VectorType& other)
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{
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if (other.size() > numElements)
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{
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reserve (other.size());
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for (size_type i = 0; i < numElements; ++i)
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elements[i] = other[i];
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for (size_type i = numElements; i < other.size(); ++i)
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new (elements + i) value_type (other[i]);
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numElements = other.size();
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}
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else
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{
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shrink (other.size());
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for (size_type i = 0; i < numElements; ++i)
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elements[i] = other[i];
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}
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return *this;
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}
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::resetToInternalStorage() noexcept
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{
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elements = getInternalStorage();
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numAllocated = preSize;
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}
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::freeHeapAndResetToInternalStorage() noexcept
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{
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if (! isUsingInternalStorage())
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{
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delete[] reinterpret_cast<char*> (elements);
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resetToInternalStorage();
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}
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}
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::reference SmallVector<ElementType, preSize>::operator[] (size_type index)
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{
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DISTRHO_SAFE_ASSERT_RETURN (index < numElements, _nullValue());
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return elements[index];
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}
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::const_reference SmallVector<ElementType, preSize>::operator[] (size_type index) const
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{
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DISTRHO_SAFE_ASSERT_RETURN (index < numElements, _nullValue());
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return elements[index];
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}
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::value_type* SmallVector<ElementType, preSize>::data() const noexcept { return elements; }
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::const_iterator SmallVector<ElementType, preSize>::begin() const noexcept { return elements; }
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::const_iterator SmallVector<ElementType, preSize>::end() const noexcept { return elements + numElements; }
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::const_iterator SmallVector<ElementType, preSize>::cbegin() const noexcept { return elements; }
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::const_iterator SmallVector<ElementType, preSize>::cend() const noexcept { return elements + numElements; }
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::iterator SmallVector<ElementType, preSize>::begin() noexcept { return elements; }
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::iterator SmallVector<ElementType, preSize>::end() noexcept { return elements + numElements; }
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::reference SmallVector<ElementType, preSize>::front()
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{
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DISTRHO_SAFE_ASSERT_RETURN (! empty(), _nullValue());
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return elements[0];
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}
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::const_reference SmallVector<ElementType, preSize>::front() const
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{
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DISTRHO_SAFE_ASSERT_RETURN (! empty(), _nullValue());
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return elements[0];
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}
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::reference SmallVector<ElementType, preSize>::back()
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{
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DISTRHO_SAFE_ASSERT_RETURN (! empty(), _nullValue());
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return elements[numElements - 1];
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}
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::const_reference SmallVector<ElementType, preSize>::back() const
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{
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DISTRHO_SAFE_ASSERT_RETURN (! empty(), _nullValue());
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return elements[numElements - 1];
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}
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::size_type SmallVector<ElementType, preSize>::size() const noexcept { return numElements; }
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::size_type SmallVector<ElementType, preSize>::length() const noexcept { return numElements; }
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template <typename ElementType, size_t preSize>
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typename SmallVector<ElementType, preSize>::size_type SmallVector<ElementType, preSize>::capacity() const noexcept { return numAllocated; }
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template <typename ElementType, size_t preSize>
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bool SmallVector<ElementType, preSize>::empty() const noexcept { return numElements == 0; }
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template <typename ElementType, size_t preSize>
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bool SmallVector<ElementType, preSize>::contains (const ElementType& target) const
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{
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for (size_t i = 0; i < numElements; ++i)
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if (elements[i] == target)
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return true;
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return false;
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}
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template <typename ElementType, size_t preSize>
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bool SmallVector<ElementType, preSize>::operator== (span<value_type> other) const { return span<value_type> (*this) == other; }
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template <typename ElementType, size_t preSize>
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bool SmallVector<ElementType, preSize>::operator!= (span<value_type> other) const { return span<value_type> (*this) != other; }
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::push_back (const value_type& item)
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{
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reserve (numElements + 1);
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new (elements + numElements) value_type (item);
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++numElements;
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}
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::push_back (value_type&& item)
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{
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reserve (numElements + 1);
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new (elements + numElements) value_type (std::move (item));
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++numElements;
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}
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template <typename ElementType, size_t preSize>
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template <typename... Others>
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void SmallVector<ElementType, preSize>::push_back (const value_type& first, Others&&... others)
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{
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reserve (numElements + 1 + sizeof... (others));
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push_back (first);
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push_back (std::forward<Others> (others)...);
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}
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template <typename ElementType, size_t preSize>
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template <typename... ConstructorArgs>
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void SmallVector<ElementType, preSize>::emplace_back (ConstructorArgs&&... args)
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{
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reserve (numElements + 1);
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new (elements + numElements) value_type (std::forward<ConstructorArgs> (args)...);
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++numElements;
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}
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::insert (iterator insertPos, const value_type& item)
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{
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DISTRHO_SAFE_ASSERT_RETURN (insertPos != nullptr && insertPos >= begin() && insertPos <= end(),);
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auto index = insertPos - begin();
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push_back (item);
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std::rotate (begin() + index, end() - 1, end());
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}
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::insert (iterator insertPos, value_type&& item)
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{
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DISTRHO_SAFE_ASSERT_RETURN (insertPos != nullptr && insertPos >= begin() && insertPos <= end(),);
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auto index = insertPos - begin();
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push_back (std::move (item));
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std::rotate (begin() + index, end() - 1, end());
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}
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::pop_back()
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{
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if (numElements == 1)
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{
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clear();
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}
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else
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{
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DISTRHO_SAFE_ASSERT_RETURN (numElements > 0,);
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elements[--numElements].~value_type();
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}
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}
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::clear() noexcept
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{
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for (size_type i = 0; i < numElements; ++i)
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elements[i].~value_type();
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numElements = 0;
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freeHeapAndResetToInternalStorage();
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}
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::resize (size_type newSize)
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{
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if (newSize > numElements)
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{
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reserve (newSize);
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while (numElements < newSize)
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new (elements + numElements++) value_type (value_type());
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}
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else
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{
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shrink (newSize);
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}
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}
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template <typename ElementType, size_t preSize>
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void SmallVector<ElementType, preSize>::shrink (size_type newSize)
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{
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if (newSize == 0)
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return clear();
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DISTRHO_SAFE_ASSERT_RETURN (newSize <= numElements,);
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while (newSize < numElements && numElements > 0)
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elements[--numElements].~value_type();
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}
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|
||||
template <typename ElementType, size_t preSize>
|
||||
void SmallVector<ElementType, preSize>::reserve (size_type requiredNumElements)
|
||||
{
|
||||
if (requiredNumElements > numAllocated)
|
||||
{
|
||||
requiredNumElements = static_cast<size_type> ((requiredNumElements + 15u) & ~(size_type) 15u);
|
||||
|
||||
if (requiredNumElements > preSize)
|
||||
{
|
||||
auto* newBuffer = reinterpret_cast<value_type*> (new char[requiredNumElements * sizeof (value_type)]);
|
||||
|
||||
for (size_type i = 0; i < numElements; ++i)
|
||||
{
|
||||
new (newBuffer + i) value_type (std::move (elements[i]));
|
||||
elements[i].~value_type();
|
||||
}
|
||||
|
||||
freeHeapAndResetToInternalStorage();
|
||||
elements = newBuffer;
|
||||
}
|
||||
|
||||
numAllocated = requiredNumElements;
|
||||
}
|
||||
}
|
||||
|
||||
template <typename ElementType, size_t preSize>
|
||||
void SmallVector<ElementType, preSize>::erase (iterator startElement)
|
||||
{
|
||||
erase (startElement, startElement + 1);
|
||||
}
|
||||
|
||||
template <typename ElementType, size_t preSize>
|
||||
void SmallVector<ElementType, preSize>::erase (iterator startElement, iterator endElement)
|
||||
{
|
||||
DISTRHO_SAFE_ASSERT_RETURN (startElement != nullptr && startElement >= begin() && startElement <= end(),);
|
||||
DISTRHO_SAFE_ASSERT_RETURN (endElement != nullptr && endElement >= begin() && endElement <= end(),);
|
||||
|
||||
if (startElement != endElement)
|
||||
{
|
||||
DISTRHO_SAFE_ASSERT_RETURN (startElement < endElement,);
|
||||
|
||||
if (endElement == end())
|
||||
return shrink (static_cast<size_type> (startElement - begin()));
|
||||
|
||||
auto dest = startElement;
|
||||
|
||||
for (auto src = endElement; src < end(); ++dest, ++src)
|
||||
*dest = std::move (*src);
|
||||
|
||||
shrink (size() - static_cast<size_type> (endElement - startElement));
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
#endif // CHOC_SMALLVECTOR_HEADER_INCLUDED
|
||||
Loading…
Add table
Add a link
Reference in a new issue