1/*
2* Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
3*
4* This software is provided 'as-is', without any express or implied
5* warranty. In no event will the authors be held liable for any damages
6* arising from the use of this software.
7* Permission is granted to anyone to use this software for any purpose,
8* including commercial applications, and to alter it and redistribute it
9* freely, subject to the following restrictions:
10* 1. The origin of this software must not be misrepresented; you must not
11* claim that you wrote the original software. If you use this software
12* in a product, an acknowledgment in the product documentation would be
13* appreciated but is not required.
14* 2. Altered source versions must be plainly marked as such, and must not be
15* misrepresented as being the original software.
16* 3. This notice may not be removed or altered from any source distribution.
17*/
18
19#ifndef B2_BLOCK_ALLOCATOR_H
20#define B2_BLOCK_ALLOCATOR_H
21
22#include <Box2D/Common/b2Settings.h>
23
24const int32 b2_chunkSize = 16 * 1024;
25const int32 b2_maxBlockSize = 640;
26const int32 b2_blockSizes = 14;
27const int32 b2_chunkArrayIncrement = 128;
28
29struct b2Block;
30struct b2Chunk;
31
32/// This is a small object allocator used for allocating small
33/// objects that persist for more than one time step.
34/// See: http://www.codeproject.com/useritems/Small_Block_Allocator.asp
35class b2BlockAllocator
36{
37public:
38 b2BlockAllocator();
39 ~b2BlockAllocator();
40
41 /// Allocate memory. This will use b2Alloc if the size is larger than b2_maxBlockSize.
42 void* Allocate(int32 size);
43
44 /// Free memory. This will use b2Free if the size is larger than b2_maxBlockSize.
45 void Free(void* p, int32 size);
46
47 void Clear();
48
49private:
50
51 b2Chunk* m_chunks;
52 int32 m_chunkCount;
53 int32 m_chunkSpace;
54
55 b2Block* m_freeLists[b2_blockSizes];
56
57 static int32 s_blockSizes[b2_blockSizes];
58 static uint8 s_blockSizeLookup[b2_maxBlockSize + 1];
59 static bool s_blockSizeLookupInitialized;
60};
61
62#endif
63