/*

 * Copyright (c) 2004, 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.runtime;

import java.util.*;

import sun.jvm.hotspot.debugger.*;

import sun.jvm.hotspot.runtime.*;

import sun.jvm.hotspot.types.*;

import sun.jvm.hotspot.utilities.*;

/** This class represent VM's Arguments class -- command line args, flags etc.*/

public class Arguments {

    static {

        VM.registerVMInitializedObserver(new Observer() {

            public void update(Observable o, Object data) {

                initialize(VM.getVM().getTypeDataBase());

            }

        });

    }

    public static String getJVMFlags() {

        return buildString(jvmFlagsField, jvmFlagsCount);

    }

    public static String getJVMArgs() {

        return buildString(jvmArgsField, jvmArgsCount);

    }

    public static String getJavaCommand() {

        return getString(javaCommandField);

    }

    // Internals only below this point

    // Fields

    private static AddressField jvmFlagsField;

    private static AddressField jvmArgsField;

    private static AddressField javaCommandField;

    private static long jvmFlagsCount;

    private static long jvmArgsCount;

    private static synchronized void initialize(TypeDataBase db) {

        Type argumentsType = db.lookupType("Arguments");

        jvmFlagsField = argumentsType.getAddressField("_jvm_flags_array");

        jvmArgsField = argumentsType.getAddressField("_jvm_args_array");

        javaCommandField = argumentsType.getAddressField("_java_command");

        jvmArgsCount = argumentsType.getCIntegerField("_num_jvm_args").getValue();

        jvmFlagsCount = argumentsType.getCIntegerField("_num_jvm_flags").getValue();

    }

    private static String buildString(AddressField arrayField, long count) {

        StringBuilder sb = new StringBuilder();

        if (count > 0) {

            sb.append(getStringAt(arrayField, 0));

            for (long i = 1; i < count; i++) {

                sb.append(" ");

                sb.append(getStringAt(arrayField, i));

            }

        }

        return sb.toString();

    }

    private static String getString(AddressField field) {

        Address addr = field.getAddress();

        return CStringUtilities.getString(addr);

    }

    private static String getStringAt(AddressField field, long index) {

        Address addr = field.getAddress();

        return CStringUtilities.getString(addr.getAddressAt(index * VM.getVM().getAddressSize()));

    }

}