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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/encode/encode_bignum.c
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The R13B03 release.OTP_R13B03
Diffstat (limited to 'lib/erl_interface/src/encode/encode_bignum.c')
-rw-r--r--lib/erl_interface/src/encode/encode_bignum.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/lib/erl_interface/src/encode/encode_bignum.c b/lib/erl_interface/src/encode/encode_bignum.c
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+++ b/lib/erl_interface/src/encode/encode_bignum.c
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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"
+
+#if defined(HAVE_GMP_H) && defined(HAVE_LIBGMP)
+
+#include <gmp.h>
+
+#include "eidef.h"
+#include "eiext.h"
+#include "putget.h"
+#include "ei_x_encode.h"
+
+int ei_encode_bignum(char *buf, int *index, mpz_t obj)
+{
+ char *s = buf + *index;
+ char *s0 = s;
+ size_t count;
+ int mpz_sign = mpz_sgn(obj);
+
+ /*
+ * FIXME we could code into ERL_[SMALL_]INTEGER_EXT but to make
+ * this code simple for now we always code into ERL_SMALL_BIG_EXT
+ */
+
+ if (mpz_sign == 0) { /* Special case, bignum is zero */
+ if (!buf) s += 2;
+ else {
+ put8(s,ERL_SMALL_INTEGER_EXT);
+ put8(s,0);
+ }
+ } else {
+
+ if (!buf) {
+ int numb = 8; /* # bits in each external format limb */
+ s += (mpz_sizeinbase(obj, 2) + numb-1) / numb;
+ } else {
+ char *arityp;
+
+ put8(s,ERL_LARGE_BIG_EXT);
+ arityp = s; /* fill in later */
+ s += 4;
+ put8(s, mpz_sign == 1); /* save sign separately */
+ mpz_export(s, &count, -1, 1, 0, 0, obj);
+ s += count;
+ put32le(arityp, count);
+ }
+ }
+
+ *index += s-s0;
+
+ return 0;
+}
+
+int ei_x_encode_bignum(ei_x_buff* x, mpz_t n)
+{
+ int i = x->index;
+ ei_encode_bignum(NULL, &i, n);
+ if (!x_fix_buff(x, i))
+ return -1;
+ return ei_encode_bignum(x->buff, &x->index, n);
+}
+
+#endif /* HAVE_GMP_H && HAVE_LIBGMP */