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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/registry/hash_dohash.c
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The R13B03 release.OTP_R13B03
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diff --git a/lib/erl_interface/src/registry/hash_dohash.c b/lib/erl_interface/src/registry/hash_dohash.c
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+/*
+ * %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 "hash.h"
+
+/* This is hashpjw, from the dragon book */
+/* Note that this function is only used as a default hash function.
+ * All calls are made through the hash pointer in the tab structure.
+ * The only place this function is explicitly referenced is in
+ * hash_newtab(); Users can use hash_setfunc() to change the hash function.
+ */
+int ei_dohash(const char *key)
+{
+ const char *s;
+ unsigned h = 0;
+ unsigned g;
+
+ for (s=key; *s; s++) {
+ h = (h << 4) + *s;
+ if ((g = (h & 0xf0000000))) { /* assumes 32-bit int */
+ h = h^(g >> 24);
+ h = h^g;
+ }
+ }
+ return h;
+}
+
+