1/*
2 * Copyright (c) 2000, 2006, 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.io.*;
28import java.util.*;
29
30import sun.jvm.hotspot.debugger.*;
31
32/** A utility class encapsulating useful operations on C strings
33    represented as Addresses */
34
35public class CStringUtilities {
36  /** Return the length of a null-terminated ASCII string in the
37      remote process */
38  public static int getStringLength(Address addr) {
39    int i = 0;
40    while (addr.getCIntegerAt(i, 1, false) != 0) {
41      i++;
42    }
43    return i;
44  }
45
46  private static String encoding = System.getProperty("file.encoding", "US-ASCII");
47
48  /** Fetch a null-terminated ASCII string from the remote process.
49      Returns null if the argument is null, otherwise returns a
50      non-null string (for example, returns an empty string if the
51      first character fetched is the null terminator). */
52  public static String getString(Address addr) {
53    if (addr == null) {
54      return null;
55    }
56
57    List data = new ArrayList();
58    byte val = 0;
59    long i = 0;
60    do {
61      val = (byte) addr.getCIntegerAt(i, 1, false);
62      if (val != 0) {
63        data.add(new Byte(val));
64      }
65      ++i;
66    } while (val != 0);
67
68    // Convert to byte[] and from there to String
69    byte[] bytes = new byte[data.size()];
70    for (i = 0; i < data.size(); ++i) {
71      bytes[(int) i] = ((Byte) data.get((int) i)).byteValue();
72    }
73    // FIXME: When we switch to use JDK 6 to build SA,
74    // we can change the following to just return:
75    // return new String(bytes, Charset.defaultCharset());
76    try {
77      return new String(bytes, encoding);
78    } catch (UnsupportedEncodingException e) {
79      throw new RuntimeException("Error converting bytes to String using " + encoding + " encoding", e);
80    }
81  }
82}
83