73 lines
1.9 KiB
D
73 lines
1.9 KiB
D
module ecs.block_allocator;
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import ecs.manager;
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import ecs.std;
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struct BlockAllocator
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{
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private uint block_size;
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private uint blocks_in_allocation;
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struct BlockPointers
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{
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void*[32] blocks;
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uint numberof = 0;
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BlockPointers* next_pointers = null;
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}
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void* next_block = null;
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BlockPointers* pointers = null;
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void* getBlock() nothrow @nogc
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{
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if (next_block is null)
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allocBlock();
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void* ret = next_block;
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next_block = *cast(void**) next_block;
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return ret;
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}
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void freeBlock(void* block) nothrow @nogc
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{
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*cast(void**)block = next_block;
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next_block = block;
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}
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private void allocBlock() nothrow @nogc
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{
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next_block = cast(void*) Mallocator.alignAlloc(
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block_size * blocks_in_allocation, block_size);
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if(pointers is null)pointers = Mallocator.make!BlockPointers;
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if(pointers.numberof >= 32)
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{
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BlockPointers* new_pointers = Mallocator.make!BlockPointers;
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new_pointers.next_pointers = pointers;
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pointers = new_pointers;
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}
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pointers.blocks[pointers.numberof++] = next_block;
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foreach (i; 0 .. blocks_in_allocation - 1)
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{
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void** pointer = cast(void**)(next_block + i * block_size);
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*pointer = next_block + (i + 1) * block_size;
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}
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void** pointer = cast(void**)(
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next_block + (blocks_in_allocation - 1) * block_size);
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*pointer = null;
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}
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void freeMemory() nothrow @nogc
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{
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while(pointers)
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{
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foreach(i;0..pointers.numberof)
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{
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Mallocator.alignDispose(pointers.blocks[i]);
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}
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BlockPointers* next_pointers = pointers.next_pointers;
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Mallocator.dispose(pointers);
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pointers = next_pointers;
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}
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}
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}
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