/*

 * Copyright (c) 2015, 2017, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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 java.lang;

final class LiveStackFrameInfo extends StackFrameInfo implements LiveStackFrame {

    private static Object[] EMPTY_ARRAY = new Object[0];

    // These flags must match the values maintained in the VM

    private static final int MODE_INTERPRETED = 0x01;

    private static final int MODE_COMPILED    = 0x02;

    LiveStackFrameInfo(StackWalker walker) {

        super(walker);

    }

    // These fields are initialized by the VM if ExtendedOption.LOCALS_AND_OPERANDS is set

    private Object[] monitors = EMPTY_ARRAY;

    private Object[] locals = EMPTY_ARRAY;

    private Object[] operands = EMPTY_ARRAY;

    private int mode = 0;

    @Override

    public Object[] getMonitors() {

        return monitors;

    }

    @Override

    public Object[] getLocals() {

        return locals;

    }

    @Override

    public Object[] getStack() {

        return operands;

    }

    @Override

    public String toString() {

        StringBuilder retVal = new StringBuilder(super.toString());

        if (mode != 0) {

            retVal.append("(");

            if ((mode & MODE_INTERPRETED) == MODE_INTERPRETED) {

                retVal.append(" interpreted ");

            }

            if ((mode & MODE_COMPILED) == MODE_COMPILED) {

                retVal.append(" compiled ");

            }

            retVal.append(")");

        }

        return retVal.toString();

    }

    /*

     * Convert primitive value to {@code PrimitiveSlot} object to represent

     * a local variable or an element on the operand stack of primitive type.

     */

    static PrimitiveSlot asPrimitive(int value) {

        return new PrimitiveSlot32(value);

    }

    static PrimitiveSlot asPrimitive(long value) {

        return new PrimitiveSlot64(value);

    }

    private static class PrimitiveSlot32 extends PrimitiveSlot {

        final int value;

        PrimitiveSlot32(int value) {

            this.value = value;

        }

        @Override

        public int size() {

            return 4;

        }

        @Override

        public int intValue() {

            return value;

        }

        @Override

        public String toString() {

            return String.valueOf(value);

        }

    }

    private static class PrimitiveSlot64 extends PrimitiveSlot {

        final long value;

        PrimitiveSlot64(long value) {

            this.value = value;

        }

        @Override

        public int size() {

            return 8;

        }

        @Override

        public long longValue() {

            return value;

        }

        @Override

        public String toString() {

            return String.valueOf(value);

        }

    }

}