conterm/libmp/mpfmt.c

194 lines
2.7 KiB
C

#include "os.h"
#include <mp.h>
#include <libsec.h>
#include "dat.h"
static int
to64(mpint *b, char *buf, int len)
{
uchar *p;
int n, rv;
p = nil;
n = mptobe(b, nil, 0, &p);
if(n < 0)
return -1;
rv = enc64(buf, len, p, n);
free(p);
return rv;
}
static int
to32(mpint *b, char *buf, int len)
{
uchar *p;
int n, rv;
// leave room for a multiple of 5 buffer size
n = b->top*Dbytes + 5;
p = malloc(n);
if(p == nil)
return -1;
n = mptobe(b, p, n, nil);
if(n < 0)
return -1;
// round up buffer size, enc32 only accepts a multiple of 5
if(n%5)
n += 5 - (n%5);
rv = enc32(buf, len, p, n);
free(p);
return rv;
}
static char set16[] = "0123456789ABCDEF";
static int
to16(mpint *b, char *buf, int len)
{
mpdigit *p, x;
int i, j;
char *out, *eout;
if(len < 1)
return -1;
out = buf;
eout = buf+len;
for(p = &b->p[b->top-1]; p >= b->p; p--){
x = *p;
for(i = Dbits-4; i >= 0; i -= 4){
j = 0xf & (x>>i);
if(j != 0 || out != buf){
if(out >= eout)
return -1;
*out++ = set16[j];
}
}
}
if(out == buf)
*out++ = '0';
if(out >= eout)
return -1;
*out = 0;
return 0;
}
static char*
modbillion(int rem, ulong r, char *out, char *buf)
{
ulong rr;
int i;
for(i = 0; i < 9; i++){
rr = r%10;
r /= 10;
if(out <= buf)
return nil;
*--out = '0' + rr;
if(rem == 0 && r == 0)
break;
}
return out;
}
static int
to10(mpint *b, char *buf, int len)
{
mpint *d, *r, *billion;
char *out;
if(len < 1)
return -1;
d = mpcopy(b);
r = mpnew(0);
billion = uitomp(1000000000, nil);
out = buf+len;
*--out = 0;
do {
mpdiv(d, billion, d, r);
out = modbillion(d->top, r->p[0], out, buf);
if(out == nil)
break;
} while(d->top != 0);
mpfree(d);
mpfree(r);
mpfree(billion);
if(out == nil)
return -1;
len -= out-buf;
if(out != buf)
memmove(buf, out, len);
return 0;
}
int
mpfmt(Fmt *fmt)
{
mpint *b;
char *p;
b = va_arg(fmt->args, mpint*);
if(b == nil)
return fmtstrcpy(fmt, "*");
p = mptoa(b, fmt->prec, nil, 0);
fmt->flags &= ~FmtPrec;
if(p == nil)
return fmtstrcpy(fmt, "*");
else{
fmtstrcpy(fmt, p);
free(p);
return 0;
}
}
char*
mptoa(mpint *b, int base, char *buf, int len)
{
char *out;
int rv, alloced;
alloced = 0;
if(buf == nil){
len = ((b->top+1)*Dbits+2)/3 + 1;
buf = malloc(len);
if(buf == nil)
return nil;
alloced = 1;
}
if(len < 2)
return nil;
out = buf;
if(b->sign < 0){
*out++ = '-';
len--;
}
switch(base){
case 64:
rv = to64(b, out, len);
break;
case 32:
rv = to32(b, out, len);
break;
default:
case 16:
rv = to16(b, out, len);
break;
case 10:
rv = to10(b, out, len);
break;
}
if(rv < 0){
if(alloced)
free(buf);
return nil;
}
return buf;
}