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authorErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
committerErlang/OTP <[email protected]>2009-11-20 14:54:40 +0000
commit84adefa331c4159d432d22840663c38f155cd4c1 (patch)
treebff9a9c66adda4df2106dfd0e5c053ab182a12bd /lib/erl_interface/src/decode/decode_long.c
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The R13B03 release.OTP_R13B03
Diffstat (limited to 'lib/erl_interface/src/decode/decode_long.c')
-rw-r--r--lib/erl_interface/src/decode/decode_long.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/lib/erl_interface/src/decode/decode_long.c b/lib/erl_interface/src/decode/decode_long.c
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+++ b/lib/erl_interface/src/decode/decode_long.c
@@ -0,0 +1,86 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 1998-2009. 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"
+
+#ifndef EI_64BIT
+int ei_decode_long(const char *buf, int *index, long *p)
+{
+ const char *s = buf + *index;
+ const char *s0 = s;
+ long 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;
+ unsigned long u = 0;
+
+ /* Little Endian, and n always positive, except for LONG_MIN */
+ for (i = 0; i < arity; i++) {
+ if (i < 4) {
+ u |= 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 > 0x80000000UL) {
+ return -1;
+ }
+ n = -((long)u);
+ } else {
+ if (u > 0x7FFFFFFF) {
+ return -1;
+ }
+ n = (long)u;
+ }
+ }
+ break;
+
+ default:
+ return -1;
+ }
+
+ if (p) *p = n;
+ *index += s-s0;
+
+ return 0;
+}
+#endif /* !EI_64BIT */