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/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2002-2009. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved online at http://www.erlang.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* %CopyrightEnd%
*/
#include "eidef.h"
#include "eiext.h"
#include "putget.h"
#ifdef EI_64BIT
int ei_decode_long(const char *buf, int *index, long *p)
{
return ei_decode_longlong(buf, index, (EI_LONGLONG *)p);
}
#endif
#ifdef _MSC_VER
#define MAX_TO_NEGATE 0x8000000000000000Ui64
#define MAX_TO_NOT_NEGATE 0x7FFFFFFFFFFFFFFFUi64
#else
#define MAX_TO_NEGATE 0x8000000000000000ULL
#define MAX_TO_NOT_NEGATE 0x7FFFFFFFFFFFFFFFULL
#endif
int ei_decode_longlong(const char *buf, int *index, EI_LONGLONG *p)
{
const char *s = buf + *index;
const char *s0 = s;
EI_LONGLONG n;
int arity;
switch (get8(s)) {
case ERL_SMALL_INTEGER_EXT:
n = get8(s);
break;
case ERL_INTEGER_EXT:
n = get32be(s);
break;
case ERL_SMALL_BIG_EXT:
arity = get8(s);
goto decode_big;
case ERL_LARGE_BIG_EXT:
arity = get32be(s);
decode_big:
{
int sign = get8(s);
int i;
EI_ULONGLONG u = 0;
/* Little Endian, and n always positive, except for LONG_MIN */
for (i = 0; i < arity; i++) {
if (i < 8) {
/* Use ULONGLONG not to get a negative integer if > 127 */
u |= ((EI_ULONGLONG)get8(s)) << (i * 8);
} else if (get8(s) != 0) {
return -1; /* All but first byte have to be 0 */
}
}
/* check for overflow */
if (sign) {
if (u > MAX_TO_NEGATE) {
return -1;
}
n = -((EI_LONGLONG) u);
} else {
if (u > MAX_TO_NOT_NEGATE) {
return -1;
}
n = (EI_LONGLONG) u;
}
}
break;
default:
return -1;
}
if (p) *p = n;
*index += s-s0;
return 0;
}
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