1 files changed, 63 insertions, 0 deletions
diff --git a/dbm/sdbm/sdbm_hash.c b/dbm/sdbm/sdbm_hash.c
new file mode 100644
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+++ b/dbm/sdbm/sdbm_hash.c
@@ -0,0 +1,63 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * sdbm - ndbm work-alike hashed database library
+ * based on Per-Aake Larson's Dynamic Hashing algorithms. BIT 18 (1978).
+ * author: oz@nexus.yorku.ca
+ * status: ex-public domain. keep it that way.
+ *
+ * hashing routine
+ */
+
+#include "apr_sdbm.h"
+#include "sdbm_private.h"
+
+/*
+ * polynomial conversion ignoring overflows
+ * [this seems to work remarkably well, in fact better
+ * then the ndbm hash function. Replace at your own risk]
+ * use: 65599	nice.
+ *      65587   even better. 
+ */
+long sdbm_hash(const char *str, int len)
+{
+	register unsigned long n = 0;
+
+#define DUFF	/* go ahead and use the loop-unrolled version */
+#ifdef DUFF
+
+#define HASHC	n = *str++ + 65599 * n
+
+	if (len > 0) {
+		register int loop = (len + 8 - 1) >> 3;
+
+		switch(len & (8 - 1)) {
+		case 0:	do {
+			HASHC;	case 7:	HASHC;
+		case 6:	HASHC;	case 5:	HASHC;
+		case 4:	HASHC;	case 3:	HASHC;
+		case 2:	HASHC;	case 1:	HASHC;
+			} while (--loop);
+		}
+
+	}
+#else
+	while (len--)
+		n = *str++ + 65599 * n;
+#endif
+	return n;
+}