69 lines
2.9 KiB
C
69 lines
2.9 KiB
C
/*************************************************************************
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* *
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* Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. *
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* All rights reserved. Email: russ@q12.org Web: www.q12.org *
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* *
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* This library is free software; you can redistribute it and/or *
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* modify it under the terms of EITHER: *
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* (1) The GNU Lesser General Public License as published by the Free *
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* Software Foundation; either version 2.1 of the License, or (at *
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* your option) any later version. The text of the GNU Lesser *
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* General Public License is included with this library in the *
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* file LICENSE.TXT. *
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* (2) The BSD-style license that is included with this library in *
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* the file LICENSE-BSD.TXT. *
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* *
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* This library is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files *
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* LICENSE.TXT and LICENSE-BSD.TXT for more details. *
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* *
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*************************************************************************/
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#ifndef _ODE_OBSTACK_H_
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#define _ODE_OBSTACK_H_
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#include "objects.h"
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// each obstack Arena pointer points to a block of this many bytes
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#define dOBSTACK_ARENA_SIZE 16384
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struct dObStack : public dBase {
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struct Arena {
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Arena *next; // next arena in linked list
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size_t used; // total number of bytes used in this arena, counting
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}; // this header
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Arena *first; // head of the arena linked list. 0 if no arenas yet
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Arena *last; // arena where blocks are currently being allocated
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// used for iterator
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Arena *current_arena;
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size_t current_ofs;
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dObStack();
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~dObStack();
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void *alloc (int num_bytes);
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// allocate a block in the last arena, allocating a new arena if necessary.
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// it is a runtime error if num_bytes is larger than the arena size.
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void freeAll();
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// free all blocks in all arenas. this does not deallocate the arenas
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// themselves, so future alloc()s will reuse them.
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void *rewind();
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// rewind the obstack iterator, and return the address of the first
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// allocated block. return 0 if there are no allocated blocks.
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void *next (int num_bytes);
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// return the address of the next allocated block. 'num_bytes' is the size
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// of the previous block. this returns null if there are no more arenas.
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// the sequence of 'num_bytes' parameters passed to next() during a
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// traversal of the list must exactly match the parameters passed to alloc().
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};
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#endif
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