/*

 * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * 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 com.sun.org.apache.bcel.internal.classfile;

import java.io.DataInput;

import java.io.DataOutputStream;

import java.io.IOException;

import com.sun.org.apache.bcel.internal.Const;

/**

 * This class represents a stack map attribute used for

 * preverification of Java classes for the <a

 * href="https://www.oracle.com/java/technologies/javameoverview.html">Java Platform, Micro Edition</a>

 * (Java ME). This attribute is used by the <a

 * href="https://www.oracle.com/technetwork/java/embedded/javame/java-mobile/kvmwp-150240.pdf">KVM</a>

 * and contained within the Code attribute of a method. See CLDC specification

 * 5.3.1.2

 *

 * @see     Code

 * @see     StackMapEntry

 * @see     StackMapType

 * @LastModified: Oct 2020

 */

public final class StackMap extends Attribute {

    private StackMapEntry[] map; // Table of stack map entries

    /*

     * @param name_index Index of name

     * @param length Content length in bytes

     * @param map Table of stack map entries

     * @param constant_pool Array of constants

     */

    public StackMap(final int name_index, final int length, final StackMapEntry[] map, final ConstantPool constant_pool) {

        super(Const.ATTR_STACK_MAP, name_index, length, constant_pool);

        this.map = map;

    }

    /**

     * Construct object from input stream.

     *

     * @param name_index Index of name

     * @param length Content length in bytes

     * @param input Input stream

     * @param constant_pool Array of constants

     * @throws IOException

     */

    StackMap(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException {

        this(name_index, length, (StackMapEntry[]) null, constant_pool);

        final int map_length = input.readUnsignedShort();

        map = new StackMapEntry[map_length];

        for (int i = 0; i < map_length; i++) {

            map[i] = new StackMapEntry(input, constant_pool);

        }

    }

    /**

     * Dump stack map table attribute to file stream in binary format.

     *

     * @param file Output file stream

     * @throws IOException

     */

    @Override

    public void dump( final DataOutputStream file ) throws IOException {

        super.dump(file);

        file.writeShort(map.length);

        for (final StackMapEntry entry : map) {

            entry.dump(file);

        }

    }

    /**

     * @return Array of stack map entries

     */

    public StackMapEntry[] getStackMap() {

        return map;

    }

    /**

     * @param map Array of stack map entries

     */

    public void setStackMap( final StackMapEntry[] map ) {

        this.map = map;

        int len = 2; // Length of 'number_of_entries' field prior to the array of stack maps

        for (final StackMapEntry element : map) {

            len += element.getMapEntrySize();

        }

        setLength(len);

    }

    /**

     * @return String representation.

     */

    @Override

    public String toString() {

        final StringBuilder buf = new StringBuilder("StackMap(");

        for (int i = 0; i < map.length; i++) {

            buf.append(map[i]);

            if (i < map.length - 1) {

                buf.append(", ");

            }

        }

        buf.append(')');

        return buf.toString();

    }

    /**

     * @return deep copy of this attribute

     */

    @Override

    public Attribute copy( final ConstantPool _constant_pool ) {

        final StackMap c = (StackMap) clone();

        c.map = new StackMapEntry[map.length];

        for (int i = 0; i < map.length; i++) {

            c.map[i] = map[i].copy();

        }

        c.setConstantPool(_constant_pool);

        return c;

    }

    /**

     * Called by objects that are traversing the nodes of the tree implicitely

     * defined by the contents of a Java class. I.e., the hierarchy of methods,

     * fields, attributes, etc. spawns a tree of objects.

     *

     * @param v Visitor object

     */

    @Override

    public void accept( final Visitor v ) {

        v.visitStackMap(this);

    }

    public int getMapLength() {

        return map == null ? 0 : map.length;

    }

}