diff options
Diffstat (limited to 'lib/erl_interface/src/decode/decode_longlong.c')
-rw-r--r-- | lib/erl_interface/src/decode/decode_longlong.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/lib/erl_interface/src/decode/decode_longlong.c b/lib/erl_interface/src/decode/decode_longlong.c new file mode 100644 index 0000000000..8ec9f76995 --- /dev/null +++ b/lib/erl_interface/src/decode/decode_longlong.c @@ -0,0 +1,100 @@ +/* + * %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; +} |