1/*
2 * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25package sun.jvm.hotspot.utilities;
26
27import java.util.*;
28import sun.jvm.hotspot.debugger.*;
29import sun.jvm.hotspot.types.*;
30import sun.jvm.hotspot.runtime.*;
31
32public class Hashtable extends BasicHashtable {
33  static {
34    VM.registerVMInitializedObserver(new Observer() {
35        public void update(Observable o, Object data) {
36          initialize(VM.getVM().getTypeDataBase());
37        }
38      });
39  }
40
41  private static synchronized void initialize(TypeDataBase db) {
42    // just to confirm that type exists
43    Type type = db.lookupType("IntptrHashtable");
44  }
45
46  // derived class may return Class<? extends HashtableEntry>
47  protected Class getHashtableEntryClass() {
48    return HashtableEntry.class;
49  }
50
51  public int hashToIndex(long fullHash) {
52    return (int) (fullHash % tableSize());
53  }
54
55  public Hashtable(Address addr) {
56    super(addr);
57  }
58
59  // VM's Hashtable::hash_symbol
60  protected static long hashSymbol(byte[] buf) {
61    long h = 0;
62    int s = 0;
63    int len = buf.length;
64    while (len-- > 0) {
65      h = 31*h + (0xFFL & buf[s]);
66      s++;
67    }
68    return h & 0xFFFFFFFFL;
69  }
70}
71