New multiprecision integer arithmetic suite.

[u/mdw/catacomb] / mp-io.c

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+/* -*-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 -------------------------------------------------*/