libmp/common/util.c

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */
/*  Portions Copyright(c) 1988, Sun Microsystems Inc.   */
/*  All Rights Reserved                 */

/*
 * Copyright (c) 1997, by Sun Microsystems, Inc.
 * All rights reserved.
 */

#ident  "%Z%%M% %I% %E% SMI"    /* SVr4.0 1.1   */

/* LINTLIBRARY */

#include <stdio.h>
#include <mp.h>
#include <sys/types.h>
#include "libmp.h"
#include <stdlib.h>
#include <unistd.h>

void
_mp_move(MINT *a, MINT *b)
{
    int i, j;

    _mp_xfree(b);
    b->len = a->len;
    if ((i = a->len) < 0) {
        i = -i;
    }
    if (i == 0) {
        return;
    }
    b->val = _mp_xalloc(i, "_mp_move");
    for (j = 0; j < i; j++) {
        b->val[j] = a->val[j];
    }
}

/* ARGSUSED */
/* VARARGS */
short *
_mp_xalloc(int nint, char *s)
{
    short *i;

    i = malloc(sizeof (short) * ((unsigned)nint + 2)); /* ??? 2 ??? */
#ifdef DEBUG
    (void) fprintf(stderr, "%s: %p\n", s, i);
#endif
    if (i == NULL) {
        _mp_fatal("mp: no free space");
    }
    return (i);
}

void
_mp_fatal(char *s)
{
    (void) fprintf(stderr, "%s\n", s);
    (void) fflush(stdout);
    (void) sleep(2);
    abort();
}

void
_mp_xfree(MINT *c)
{
#ifdef DBG
    (void) fprintf(stderr, "xfree ");
#endif
    if (c->len != 0) {
        free(c->val);
        c->len = 0;
    }
}

void
_mp_mcan(MINT *a)
{
    int i, j;

    if ((i = a->len) == 0) {
        return;
    }
    if (i < 0) {
        i = -i;
    }
    for (j = i; j > 0 && a->val[j-1] == 0; j--)
        ;
    if (j == i) {
        return;
    }
    if (j == 0) {
        _mp_xfree(a);
        return;
    }
    if (a->len > 0) {
        a->len = j;
    } else {
        a->len = -j;
    }
}


MINT *
mp_itom(short n)
{
    MINT *a;

    a = malloc(sizeof (MINT));
    if (n > 0) {
        a->len = 1;
        a->val = _mp_xalloc(1, "mp_itom1");
        *a->val = n;
    } else if (n < 0) {
        a->len = -1;
        a->val = _mp_xalloc(1, "mp_itom2");
        *a->val = -n;
    } else {
        a->len = 0;
    }
    return (a);
}

int
mp_mcmp(MINT *a, MINT *b)
{
    MINT c;
    int res;

    _mp_mcan(a);
    _mp_mcan(b);
    if (a->len != b->len) {
        return (a->len - b->len);
    }
    c.len = 0;
    mp_msub(a, b, &c);
    res = c.len;
    _mp_xfree(&c);
    return (res);
}

/*
 * Convert hex digit to binary value
 */
static short
xtoi(char c)
{
    if (c >= '0' && c <= '9') {
        return (c - '0');
    } else if (c >= 'a' && c <= 'f') {
        return (c - 'a' + 10);
    } else if (c >= 'A' && c <= 'F') {
        return (c - 'A' + 10);
    } else {
        return (-1);
    }
}


/*
 * Convert hex key to MINT key
 */
MINT *
mp_xtom(char *key)
{
    short digit;
    MINT *m = mp_itom(0);
    MINT *d;
    MINT *sixteen;

    sixteen = mp_itom(16);
    for (; *key; key++) {
        digit = xtoi(*key);
        if (digit < 0) {
            return (NULL);
        }
        d = mp_itom(digit);
        mp_mult(m, sixteen, m);
        mp_madd(m, d, m);
        mp_mfree(d);
    }
    mp_mfree(sixteen);
    return (m);
}

static char
itox(short d)
{
    d &= 15;
    if (d < 10) {
        return ('0' + d);
    } else {
        return ('a' - 10 + d);
    }
}

/*
 * Convert MINT key to hex key
 */
char *
mp_mtox(MINT *key)
{
    MINT *m = mp_itom(0);
    MINT *zero = mp_itom(0);
    short r;
    char *p;
    char c;
    char *s;
    char *hex;
    int size;

#define BASEBITS    (8 * (unsigned int)sizeof (short) - 1)

    if (key->len >= 0) {
        size = key->len;
    } else {
        size = -key->len;
    }
    hex = malloc((size_t) ((size * BASEBITS + 3)) / 4 + (size ? 1 : 2));
    if (hex == NULL) {
        return (NULL);
    }
    _mp_move(key, m);
    p = hex;
    do {
        mp_sdiv(m, 16, m, &r);
        *p++ = itox(r);
    } while (mp_mcmp(m, zero) != 0);
    mp_mfree(m);
    mp_mfree(zero);

    *p = 0;
    for (p--, s = hex; s < p; s++, p--) {
        c = *p;
        *p = *s;
        *s = c;
    }
    return (hex);
}

/*
 * Deallocate a multiple precision integer
 */
void
mp_mfree(MINT *a)
{
    _mp_xfree(a);
    free(a);
}