git.distorted.org.uk Git - u/mdw/catacomb/blob - math/mparena.h

   1 /* -*-c-*-
   2  *
   3  * Allocation and freeing of MP buffers
   4  *
   5  * (c) 1999 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Catacomb.
  11  *
  12  * Catacomb is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * Catacomb is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with Catacomb; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 #ifndef CATACOMB_MPARENA_H
  29 #define CATACOMB_MPARENA_H
  30
  31 #ifdef __cplusplus
  32   extern "C" {
  33 #endif
  34
  35 /*----- Header files ------------------------------------------------------*/
  36
  37 #include <mLib/arena.h>
  38
  39 #ifndef CATACOMB_MPW_H
  40 #  include "mpw.h"
  41 #endif
  42
  43 /*----- Data structures ---------------------------------------------------*/
  44
  45 /* --- @mparena_node@ --- *
  46  *
  47  * For internal use by the MP arena manager.  The free blocks are held in a
  48  * binary tree by size, held in the first digit of each vector.
  49  */
  50
  51 typedef struct mparena_node {
  52   struct mparena_node *left, *right;
  53   mpw *v;
  54 } mparena_node;
  55
  56 /* --- @mparena@ --- *
  57  *
  58  * The actual arena.
  59  */
  60
  61 typedef struct mparena {
  62   mparena_node *root;
  63   unsigned n;
  64   arena *a;
  65 } mparena;
  66
  67 /*----- Standard arenas ---------------------------------------------------*/
  68
  69 extern mparena mparena_global;
  70 #define MPARENA_GLOBAL (&mparena_global)
  71
  72 extern mparena mparena_secure;
  73 #define MPARENA_SECURE (&mparena_secure)
  74
  75 /*----- Functions provided ------------------------------------------------*/
  76
  77 /* --- @mparena_create@ --- *
  78  *
  79  * Arguments:   @mparena *a@ = pointer to arena block
  80  *
  81  * Returns:     ---
  82  *
  83  * Use:         Initializes an MP arena so that blocks can be allocated from
  84  *              it.
  85  */
  86
  87 extern void mparena_create(mparena */*a*/);
  88
  89 #define MPARENA_INIT { 0, 0, &arena_stdlib }
  90
  91 /* --- @mparena_setarena@ --- *
  92  *
  93  * Arguments:   @mparena *a@ = pointer to MP arena block
  94  *              @arena *aa@ = pointer to arena
  95  *
  96  * Returns:     ---
  97  *
  98  * Use:         Sets the underlying arena for an MP arena.
  99  */
 100
 101 extern void mparena_setarena(mparena */*a*/, arena */*aa*/);
 102
 103 /* --- @mparena_destroy@ --- *
 104  *
 105  * Arguments:   @mparena *a@ = pointer to arena block
 106  *
 107  * Returns:     ---
 108  *
 109  * Use:         Frees an MP arena, and all the vectors held within it.  The
 110  *              blocks which are currently allocated can be freed into some
 111  *              other MP arena, as long as the underlying arenas are the
 112  *              same.
 113  */
 114
 115 extern void mparena_destroy(mparena */*a*/);
 116
 117 /* --- @mparena_count@ --- *
 118  *
 119  * Arguments:   @mparena *a@ = pointer to arena block
 120  *
 121  * Returns:     Number of allocated blocks from this arena.
 122  *
 123  * Use:         Reports the number of blocks allocated from the arena and not
 124  *              yet freed.
 125  */
 126
 127 extern unsigned mparena_count(mparena */*a*/);
 128
 129 /* --- @mpalloc@ --- *
 130  *
 131  * Arguments:   @mparena *a@ = pointer to arena block
 132  *              @size_t sz@ = number of digits required
 133  *
 134  * Returns:     Pointer to a suitably sized block.
 135  *
 136  * Use:         Allocates a lump of data suitable for use as an array of MP
 137  *              digits.
 138  */
 139
 140 extern mpw *mpalloc(mparena */*a*/, size_t /*sz*/);
 141
 142 /* --- @mpfree@ --- *
 143  *
 144  * Arguments:   @mparena *a@ = pointer to arena block
 145  *              @mpw *v@ = pointer to allocated vector
 146  *
 147  * Returns:     ---
 148  *
 149  * Use:         Returns an MP vector to an arena.
 150  */
 151
 152 extern void mpfree(mparena */*a*/, mpw */*v*/);
 153
 154 /*----- That's all, folks -------------------------------------------------*/
 155
 156 #ifdef __cplusplus
 157   }
 158 #endif
 159
 160 #endif