/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.tomcat.util.bcel.classfile;

import java.io.DataInputStream;
import java.io.IOException;

import org.apache.tomcat.util.bcel.Constants;

/**
 * This class is derived from <em>Attribute</em> and declares this class as
 * `synthetic', i.e., it needs special handling.  The JVM specification
 * states "A class member that does not appear in the source code must be
 * marked using a Synthetic attribute."  It may appear in the ClassFile
 * attribute table, a field_info table or a method_info table.  This class
 * is intended to be instantiated from the
 * <em>Attribute.readAttribute()</em> method.
 *
 * @version $Id: Synthetic.java 1377533 2012-08-26 22:22:59Z markt $
 * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
 * @see     Attribute
 */
public final class Synthetic extends Attribute {

    private static final long serialVersionUID = -5129612853226360165L;
    private byte[] bytes;


    /**
     * @param name_index Index in constant pool to CONSTANT_Utf8, which
     * should represent the string "Synthetic".
     * @param length Content length in bytes - should be zero.
     * @param bytes Attribute contents
     * @param constant_pool The constant pool this attribute is associated
     * with.
     */
    public Synthetic(int name_index, int length, byte[] bytes, ConstantPool constant_pool) {
        super(Constants.ATTR_SYNTHETIC, name_index, length, constant_pool);
        this.bytes = bytes;
    }


    /**
     * Construct object from file stream.
     * @param name_index Index in constant pool to CONSTANT_Utf8
     * @param length Content length in bytes
     * @param file Input stream
     * @param constant_pool Array of constants
     * @throws IOException
     */
    Synthetic(int name_index, int length, DataInputStream file, ConstantPool constant_pool)
            throws IOException {
        this(name_index, length, (byte[]) null, constant_pool);
        if (length > 0) {
            bytes = new byte[length];
            file.readFully(bytes);
            System.err.println("Synthetic attribute with length > 0");
        }
    }


    /**
     * @return String representation.
     */
    @Override
    public final String toString() {
        StringBuilder buf = new StringBuilder("Synthetic");
        if (length > 0) {
            buf.append(" ").append(Utility.toHexString(bytes));
        }
        return buf.toString();
    }


    /**
     * @return deep copy of this attribute
     */
    @Override
    public Attribute copy( ConstantPool _constant_pool ) {
        Synthetic c = (Synthetic) clone();
        if (bytes != null) {
            c.bytes = new byte[bytes.length];
            System.arraycopy(bytes, 0, c.bytes, 0, bytes.length);
        }
        c.constant_pool = _constant_pool;
        return c;
    }
}
