reactos/dll/win32/glu32/libnurbs/internals/bufpool.h

   1 /*
   2 ** License Applicability. Except to the extent portions of this file are
   3 ** made subject to an alternative license as permitted in the SGI Free
   4 ** Software License B, Version 1.1 (the "License"), the contents of this
   5 ** file are subject only to the provisions of the License. You may not use
   6 ** this file except in compliance with the License. You may obtain a copy
   7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
   8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
   9 **
  10 ** http://oss.sgi.com/projects/FreeB
  11 **
  12 ** Note that, as provided in the License, the Software is distributed on an
  13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
  14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
  15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
  16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
  17 **
  18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
  19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
  20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
  21 ** Copyright in any portions created by third parties is as indicated
  22 ** elsewhere herein. All Rights Reserved.
  23 **
  24 ** Additional Notice Provisions: The application programming interfaces
  25 ** established by SGI in conjunction with the Original Code are The
  26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
  27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
  28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
  29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
  30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
  31 ** published by SGI, but has not been independently verified as being
  32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
  33 */
  34
  35 /*
  36  * bufpool.h
  37  *
  38  * $Date$ $Revision: 1.1 $
  39  * $Header: /cygdrive/c/RCVS/CVS/ReactOS/reactos/lib/glu32/libnurbs/internals/bufpool.h,v 1.1 2004/02/02 16:39:11 navaraf Exp $
  40  */
  41
  42 #ifndef __glubufpool_h_
  43 #define __glubufpool_h_
  44
  45 #include "gluos.h"
  46 #include "myassert.h"
  47 #include "mystdlib.h"
  48
  49 #define NBLOCKS 32
  50
  51 class Buffer {
  52         friend class    Pool;
  53         Buffer  *       next;           /* next buffer on free list     */
  54 };
  55
  56 class Pool {
  57 public:
  58                         Pool( int, int, char * );
  59                         ~Pool( void );
  60     inline void*        new_buffer( void );
  61     inline void         free_buffer( void * );
  62     void                clear( void );
  63
  64 private:
  65     void                grow( void );
  66
  67 protected:
  68     Buffer              *freelist;              /* linked list of free buffers */
  69     char                *blocklist[NBLOCKS];    /* blocks of malloced memory */
  70     int                 nextblock;              /* next free block index */
  71     char                *curblock;              /* last malloced block */
  72     int                 buffersize;             /* bytes per buffer */
  73     int                 nextsize;               /* size of next block of memory */
  74     int                 nextfree;               /* byte offset past next free buffer */
  75     int                 initsize;
  76     enum Magic { is_allocated = 0xf3a1, is_free = 0xf1a2 };
  77     char                *name;                  /* name of the pool */
  78     Magic               magic;                  /* marker for valid pool */
  79 };
  80
  81 /*-----------------------------------------------------------------------------
  82  * Pool::free_buffer - return a buffer to a pool
  83  *-----------------------------------------------------------------------------
  84  */
  85
  86 inline void
  87 Pool::free_buffer( void *b )
  88 {
  89     assert( (this != 0) && (magic == is_allocated) );
  90
  91     /* add buffer to singly connected free list */
  92
  93     ((Buffer *) b)->next = freelist;
  94     freelist = (Buffer *) b;
  95 }
  96
  97
  98 /*-----------------------------------------------------------------------------
  99  * Pool::new_buffer - allocate a buffer from a pool
 100  *-----------------------------------------------------------------------------
 101  */
 102
 103 inline void *
 104 Pool::new_buffer( void )
 105 {
 106     void *buffer;
 107
 108     assert( (this != 0) && (magic == is_allocated) );
 109
 110     /* find free buffer */
 111
 112     if( freelist ) {
 113         buffer = (void *) freelist;
 114         freelist = freelist->next;
 115     } else {
 116         if( ! nextfree )
 117             grow( );
 118         nextfree -= buffersize;
 119         buffer = (void *) (curblock + nextfree);
 120     }
 121     return buffer;
 122 }
 123
 124 class PooledObj {
 125 public:
 126     inline void *       operator new( size_t, Pool & );
 127     inline void *       operator new( size_t, void *);
 128     inline void *       operator new( size_t s)
 129                                 { return ::new char[s]; }
 130     inline void         operator delete( void * ) { assert( 0 ); }
 131     inline void         deleteMe( Pool & );
 132 };
 133
 134 inline void *
 135 PooledObj::operator new( size_t, Pool& pool )
 136 {
 137     return pool.new_buffer();
 138 }
 139
 140 inline void
 141 PooledObj::deleteMe( Pool& pool )
 142 {
 143     pool.free_buffer( (void *) this );
 144 }
 145
 146 #endif /* __glubufpool_h_ */