X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/71ec78ce88339bda7c265d6dafa4982077acc901..d3409d5ecf2492cff862616de72a580d1a8e8dc0:/mparena.h diff --git a/mparena.h b/mparena.h new file mode 100644 index 0000000..61c735e --- /dev/null +++ b/mparena.h @@ -0,0 +1,167 @@ +/* -*-c-*- + * + * $Id: mparena.h,v 1.1 1999/11/17 18:02:16 mdw Exp $ + * + * Allocation and freeing of MP buffers + * + * (c) 1999 Straylight/Edgeware + */ + +/*----- Licensing notice --------------------------------------------------* + * + * This file is part of Catacomb. + * + * Catacomb is free software; you can redistribute it and/or modify + * it under the terms of the GNU Library General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * Catacomb is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with Catacomb; if not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + * MA 02111-1307, USA. + */ + +/*----- Revision history --------------------------------------------------* + * + * $Log: mparena.h,v $ + * Revision 1.1 1999/11/17 18:02:16 mdw + * New multiprecision integer arithmetic suite. + * + */ + +#ifndef MPARENA_H +#define MPARENA_H + +#ifdef __cplusplus + extern "C" { +#endif + +/*----- Header files ------------------------------------------------------*/ + +#ifndef MPW_H +# include "mpw.h" +#endif + +/*----- Data structures ---------------------------------------------------*/ + +/* --- @mparena_node@ --- * + * + * For internal use by the MP arena manager. The free blocks are held in a + * binary tree by size, held in the first digit of each vector. + */ + +typedef struct mparena_node { + struct mparena_node *left, *right; + mpw *v; +} mparena_node; + +/* --- @mparena@ --- * + * + * The actual arena. + */ + +typedef struct mparena { + mparena_node *root; + struct mparena_ops *ops; +} mparena; + +/* --- @mparena_ops@ --- * + * + * Operations required for an arena memory manager. The default manager just + * calls @xmalloc@ and @free@, although it's possible to envisage a more + * paranoid implementation which allocates locked memory pages. Switch them + * over with @mparena_setops@. It's usual to only do this when you've + * attached your extra state to the end of the @mparena@ structure. + */ + +typedef struct mparena_ops { + void *(*alloc)(mparena */*a*/, size_t /*sz*/); + void (*free)(mparena */*a*/, void */*p*/); +} mparena_ops; + +/*----- Magical constants -------------------------------------------------*/ + +#define MPARENA_GLOBAL ((mparena *)0) + +extern mparena_ops mparena_defaultops; + +/*----- Functions provided ------------------------------------------------*/ + +/* --- @mparena_create@ --- * + * + * Arguments: @mparena *a@ = pointer to arena block + * + * Returns: --- + * + * Use: Initializes an MP arena so that blocks can be allocated from + * it. + */ + +extern void mparena_create(mparena */*a*/); + +#define MPARENA_INIT { 0, &mparena_defaultops } + +/* --- @mparena_setops@ --- * + * + * Arguments: @mparena *a@ = pointer to arena block + * @mparena_ops *ops@ = pointer to operations block or null + * + * Returns: The previous operations block. + * + * Use: Sets or queries the operations attached to an arena. + */ + +extern mparena_ops *mparena_setops(mparena */*a*/, mparena_ops */*ops*/); + +/* --- @mparena_destroy@ --- * + * + * Arguments: @mparena *a@ = pointer to arena block + * + * Returns: --- + * + * Use: Frees an MP arena, and all the vectors held within it. The + * blocks which are currently allocated can be freed into some + * other arena. + */ + +extern void mparena_destroy(mparena */*a*/); + +/* --- @mpalloc@ --- * + * + * Arguments: @mparena *a@ = pointer to arena block + * @size_t sz@ = number of digits required + * + * Returns: Pointer to a suitably sized block. + * + * Use: Allocates a lump of data suitable for use as an array of MP + * digits. + */ + +extern mpw *mpalloc(mparena */*a*/, size_t /*sz*/); + +/* --- @mpfree@ --- * + * + * Arguments: @mparena *a@ = pointer to arena block + * @mpw *v@ = pointer to allocated vector + * + * Returns: --- + * + * Use: Returns an MP vector to an arena. It doesn't have to be + * returned to the arena from which it was allocated. + */ + +extern void mpfree(mparena */*a*/, mpw */*v*/); + +/*----- That's all, folks -------------------------------------------------*/ + +#ifdef __cplusplus + } +#endif + +#endif