/* MDB Tools - A library for reading MS Access database file
* Copyright (C) 1998-1999 Brian Bruns
*
* This library 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.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include "../mdbtools.h"
#ifdef DMALLOC
#include "dmalloc.h"
#endif
#define MAX_NUMERIC_PRECISION 28
/*
** these routines are copied from the freetds project which does something
** very similiar
*/
static int multiply_byte(unsigned char *product, int num, unsigned char *multiplier);
static int do_carry(unsigned char *product);
static char *array_to_string(unsigned char *array, int unsigned scale, int neg);
/**
* mdb_money_to_string
* @mdb: Handle to open MDB database file
* @start: Offset of the field within the current page
*
* Returns: the allocated string that has received the value.
*/
char *mdb_money_to_string(MdbHandle *mdb, int start)
{
const int num_bytes=8, scale=4;
int i;
int neg=0;
unsigned char multiplier[MAX_NUMERIC_PRECISION], temp[MAX_NUMERIC_PRECISION];
unsigned char product[MAX_NUMERIC_PRECISION];
unsigned char bytes[8];
memset(multiplier,0,MAX_NUMERIC_PRECISION);
memset(product,0,MAX_NUMERIC_PRECISION);
multiplier[0]=1;
memcpy(bytes, mdb->pg_buf + start, num_bytes);
/* Perform two's complement for negative numbers */
if (bytes[num_bytes-1] & 0x80) {
neg = 1;
for (i=0;i<num_bytes;i++) {
bytes[i] = ~bytes[i];
}
for (i=0; i<num_bytes; i++) {
bytes[i] ++;
if (bytes[i]!=0) break;
}
}
for (i=0;i<num_bytes;i++) {
/* product += multiplier * current byte */
multiply_byte(product, bytes[i], multiplier);
/* multiplier = multiplier * 256 */
memcpy(temp, multiplier, MAX_NUMERIC_PRECISION);
memset(multiplier, 0, MAX_NUMERIC_PRECISION);
multiply_byte(multiplier, 256, temp);
}
return array_to_string(product, scale, neg);
}
char *mdb_numeric_to_string(MdbHandle *mdb, int start, int prec, int scale) {
const int num_bytes = 16;
int i;
int neg=0;
unsigned char multiplier[MAX_NUMERIC_PRECISION], temp[MAX_NUMERIC_PRECISION];
unsigned char product[MAX_NUMERIC_PRECISION];
unsigned char bytes[16];
memset(multiplier,0,MAX_NUMERIC_PRECISION);
memset(product,0,MAX_NUMERIC_PRECISION);
multiplier[0]=1;
memcpy(bytes, mdb->pg_buf + start + 1, num_bytes);
/* Perform two's complement for negative numbers */
if (mdb->pg_buf[start] & 0x80) neg = 1;
for (i=0;i<num_bytes;i++) {
/* product += multiplier * current byte */
multiply_byte(product, bytes[12-4*(i/4)+i%4], multiplier);
/* multiplier = multiplier * 256 */
memcpy(temp, multiplier, MAX_NUMERIC_PRECISION);
memset(multiplier, 0, MAX_NUMERIC_PRECISION);
multiply_byte(multiplier, 256, temp);
}
return array_to_string(product, scale, neg);
}
static int multiply_byte(unsigned char *product, int num, unsigned char *multiplier)
{
unsigned char number[3];
unsigned int i, j;
number[0]=num%10;
number[1]=(num/10)%10;
number[2]=(num/100)%10;
for (i=0;i<MAX_NUMERIC_PRECISION;i++) {
if (multiplier[i] == 0) continue;
for (j=0;j<3;j++) {
if (number[j] == 0) continue;
product[i+j] += multiplier[i]*number[j];
}
do_carry(product);
}
return 0;
}
static int do_carry(unsigned char *product)
{
unsigned int j;
for (j=0;j<MAX_NUMERIC_PRECISION-1;j++) {
if (product[j]>9) {
product[j+1]+=product[j]/10;
product[j]=product[j]%10;
}
}
if (product[j]>9) {
product[j]=product[j]%10;
}
return 0;
}
static char *array_to_string(unsigned char *array, unsigned int scale, int neg)
{
char *s;
unsigned int top, i, j=0;
for (top=MAX_NUMERIC_PRECISION;(top>0) && (top-1>scale) && !array[top-1];top--);
/* allocate enough space for all digits + minus sign + decimal point + trailing NULL byte */
s = (char *) g_malloc(MAX_NUMERIC_PRECISION+3);
if (neg)
s[j++] = '-';
if (top == 0) {
s[j++] = '0';
} else {
for (i=top; i>0; i--) {
if (i == scale) s[j++]='.';
s[j++]=array[i-1]+'0';
}
}
s[j]='\0';
return s;
}