/*

 * Copyright (c) 2000, 2006, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

package sun.jvm.hotspot.utilities;

import java.io.*;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

/** A utility class encapsulating useful operations on C strings

    represented as Addresses */

public class CStringUtilities {

  /** Return the length of a null-terminated ASCII string in the

      remote process */

  public static int getStringLength(Address addr) {

    int i = 0;

    while (addr.getCIntegerAt(i, 1, false) != 0) {

      i++;

    }

    return i;

  }

  private static String encoding = System.getProperty("file.encoding", "US-ASCII");

  /** Fetch a null-terminated ASCII string from the remote process.

      Returns null if the argument is null, otherwise returns a

      non-null string (for example, returns an empty string if the

      first character fetched is the null terminator). */

  public static String getString(Address addr) {

    if (addr == null) {

      return null;

    }

    List data = new ArrayList();

    byte val = 0;

    long i = 0;

    do {

      val = (byte) addr.getCIntegerAt(i, 1, false);

      if (val != 0) {

        data.add(new Byte(val));

      }

      ++i;

    } while (val != 0);

    // Convert to byte[] and from there to String

    byte[] bytes = new byte[data.size()];

    for (i = 0; i < data.size(); ++i) {

      bytes[(int) i] = ((Byte) data.get((int) i)).byteValue();

    }

    // FIXME: When we switch to use JDK 6 to build SA,

    // we can change the following to just return:

    // return new String(bytes, Charset.defaultCharset());

    try {

      return new String(bytes, encoding);

    } catch (UnsupportedEncodingException e) {

      throw new RuntimeException("Error converting bytes to String using " + encoding + " encoding", e);

    }

  }

}