X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/71ec78ce88339bda7c265d6dafa4982077acc901..d3409d5ecf2492cff862616de72a580d1a8e8dc0:/mp-io.c diff --git a/mp-io.c b/mp-io.c new file mode 100644 index 0000000..0aa2bca --- /dev/null +++ b/mp-io.c @@ -0,0 +1,149 @@ +/* -*-c-*- + * + * $Id: mp-io.c,v 1.1 1999/11/17 18:02:16 mdw Exp $ + * + * Loading and storing of multiprecision integers + * + * (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: mp-io.c,v $ + * Revision 1.1 1999/11/17 18:02:16 mdw + * New multiprecision integer arithmetic suite. + * + */ + +/*----- Header files ------------------------------------------------------*/ + +#include "mp.h" + +/*----- Main code ---------------------------------------------------------*/ + +/* --- @mp_octets@ --- * + * + * Arguments: @const mp *m@ = a multiprecision integer + * + * Returns: The number of octets required to represent @m@. + * + * Use: Calculates the external storage required for a multiprecision + * integer. + */ + +size_t mp_octets(const mp *m) +{ + size_t sz; + MPX_OCTETS(sz, m->v, m->vl); + return (sz); +} + +/* --- @mp_loadl@ --- * + * + * Arguments: @mp *d@ = destination + * @const void *pv@ = pointer to source data + * @size_t sz@ = size of the source data + * + * Returns: Resulting multiprecision number. + * + * Use: Loads a multiprecision number from an array of octets. The + * first byte in the array is the least significant. More + * formally, if the bytes are %$b_0, b_1, \ldots, b_{n-1}$% + * then the result is %$N = \sum_{0 \le i < n} b_i 2^{8i}$%. + */ + +mp *mp_loadl(mp *d, const void *pv, size_t sz) +{ + MP_MODIFY(d, MPW_RQ(sz)); + mpx_loadl(d->v, d->vl, pv, sz); + mp_shrink(d); + return (d); +} + +/* --- @mp_storel@ --- * + * + * Arguments: @const mp *m@ = source + * @void *pv@ = pointer to output array + * @size_t sz@ = size of the output array + * + * Returns: --- + * + * Use: Stores a multiprecision number in an array of octets. The + * first byte in the array is the least significant. If the + * array is too small to represent the number, high-order bits + * are truncated; if the array is too large, high order bytes + * are filled with zeros. More formally, if the number is + * %$N = \sum{0 \le i} b_i 2^{8i}$% where %$0 \le b_i < 256$%, + * then the array is %$b_0, b_1, \ldots, b_{n-1}$%. + */ + +void mp_storel(const mp *m, void *pv, size_t sz) +{ + mpx_storel(m->v, m->vl, pv, sz); +} + +/* --- @mp_loadb@ --- * + * + * Arguments: @mp *d@ = destination + * @const void *pv@ = pointer to source data + * @size_t sz@ = size of the source data + * + * Returns: Resulting multiprecision number. + * + * Use: Loads a multiprecision number from an array of octets. The + * last byte in the array is the least significant. More + * formally, if the bytes are %$b_{n-1}, b_{n-2}, \ldots, b_0$% + * then the result is %$N = \sum_{0 \le i < n} b_i 2^{8i}$%. + */ + +mp *mp_loadb(mp *d, const void *pv, size_t sz) +{ + MP_MODIFY(d, MPW_RQ(sz)); + mpx_loadb(d->v, d->vl, pv, sz); + mp_shrink(d); + return (d); +} + +/* --- @mp_storeb@ --- * + * + * Arguments: @const mp *m@ = source + * @void *pv@ = pointer to output array + * @size_t sz@ = size of the output array + * + * Returns: --- + * + * Use: Stores a multiprecision number in an array of octets. The + * last byte in the array is the least significant. If the + * array is too small to represent the number, high-order bits + * are truncated; if the array is too large, high order bytes + * are filled with zeros. More formally, if the number is + * %$N = \sum{0 \le i} b_i 2^{8i}$% where %$0 \le b_i < 256$%, + * then the array is %$b_{n-1}, b_{n-2}, \ldots, b_0$%. + */ + +void mp_storeb(const mp *m, void *pv, size_t sz) +{ + mpx_storeb(m->v, m->vl, pv, sz); +} + +/*----- That's all, folks -------------------------------------------------*/