1 files changed, 43 insertions, 0 deletions
diff --git a/lib/erl_interface/src/registry/hash_rlookup.c b/lib/erl_interface/src/registry/hash_rlookup.c
new file mode 100644
index 0000000000..5d401555d8
--- /dev/null
+++ b/lib/erl_interface/src/registry/hash_rlookup.c
@@ -0,0 +1,43 @@
+/*
+ * %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 <stdlib.h>
+#include "hash.h"
+
+/* this function does a reverse lookup and returns the first key whose
+ * value matches value. This operation may be lengthy! Also, there is
+ * no guarantee that the *values* are unique in the hash table, so the
+ * returned key might not be the one you expect. 
+ */
+const char *ei_hash_rlookup(ei_hash *tab, const void *value)
+{
+  ei_bucket *b;
+  int i;
+
+  for (i=0; i<tab->size; i++) {
+    b=tab->tab[i];
+    while (b) {
+      if (b->value == value) return b->key;
+      b = b->next;
+    }
+  }
+  return NULL;
+}
+