56 lines
1.3 KiB
C++
56 lines
1.3 KiB
C++
// Copyright (c) Wojciech Figat. All rights reserved.
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#include "Allocation.h"
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/// <summary>
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/// Allocator that uses pages for stack-based allocs without freeing memory during it's lifetime.
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/// </summary>
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class ArenaAllocator
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{
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private:
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struct Page
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{
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void* Memory;
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Page* Next;
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uint32 Offset, Size;
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};
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int32 _pageSize;
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Page* _first = nullptr;
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public:
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ArenaAllocator(int32 pageSizeBytes = 1024 * 1024) // 1 MB by default
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: _pageSize(pageSizeBytes)
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{
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}
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~ArenaAllocator()
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{
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Free();
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}
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// Allocates a chunk of unitialized memory.
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void* Allocate(uint64 size, uint64 alignment = 1);
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// Frees all memory allocations within allocator.
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void Free();
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// Creates a new object within the arena allocator.
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template<class T, class... Args>
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inline T* New(Args&&...args)
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{
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T* ptr = (T*)Allocate(sizeof(T));
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new(ptr) T(Forward<Args>(args)...);
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return ptr;
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}
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// Invokes destructor on values in a dictionary and clears it.
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template<typename Key, typename Value, typename Allocator>
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void ClearDelete(Dictionary<Key, Value, Allocator>& collection)
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{
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for (auto it = collection.Begin(); it.IsNotEnd(); ++it)
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Memory::DestructItem(it->Value);
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collection.Clear();
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}
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};
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