    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one
    003 * or more contributor license agreements.  See the NOTICE file
    004 * distributed with this work for additional information
    005 * regarding copyright ownership.  The ASF licenses this file
    006 * to you under the Apache License, Version 2.0 (the
    007 * "License"); you may not use this file except in compliance
    008 * with the License.  You may obtain a copy of the License at
    009 *
    010 *   https://www.apache.org/licenses/LICENSE-2.0
    011 *
    012 * Unless required by applicable law or agreed to in writing,
    013 * software distributed under the License is distributed on an
    014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015 * KIND, either express or implied.  See the License for the
    016 * specific language governing permissions and limitations
    017 * under the License.
    018 */
    019package org.apache.commons.compress.harmony.unpack200.bytecode;
    020
    021import java.io.DataOutputStream;
    022import java.io.IOException;
    023import java.util.Objects;
    024
    025import org.apache.commons.compress.harmony.unpack200.SegmentUtils;
    026
    027/**
    028 * Name and Type pair constant pool entry.
    029 */
    030public class CPNameAndType extends ConstantPoolEntry {
    031
    032    CPUTF8 descriptor;
    033
    034    transient int descriptorIndex;
    035
    036    CPUTF8 name;
    037
    038    transient int nameIndex;
    039
    040    private boolean hashCodeComputed;
    041
    042    private int cachedHashCode;
    043
    044    /**
    045     * Constructs a new CPNameAndType.
    046     *
    047     * @param name        TODO
    048     * @param descriptor  TODO
    049     * @param globalIndex index in CpBands
    050     * @throws NullPointerException if name or descriptor is null
    051     */
    052    public CPNameAndType(final CPUTF8 name, final CPUTF8 descriptor, final int globalIndex) {
    053        super(CP_NameAndType, globalIndex);
    054        this.name = Objects.requireNonNull(name, "name");
    055        this.descriptor = Objects.requireNonNull(descriptor, "descriptor");
    056    }
    057
    058    /*
    059     * field_info { u2 access_flags; u2 name_index; u2 descriptor_index; u2 attributes_count; attribute_info attributes[attributes_count]; }
    060     */
    061
    062    @Override
    063    public boolean equals(final Object obj) {
    064        if (this == obj) {
    065            return true;
    066        }
    067        if (obj == null || getClass() != obj.getClass()) {
    068            return false;
    069        }
    070        final CPNameAndType other = (CPNameAndType) obj;
    071        return Objects.equals(descriptor, other.descriptor)
    072                && Objects.equals(name, other.name);
    073    }
    074
    075    private void generateHashCode() {
    076        hashCodeComputed = true;
    077        final int PRIME = 31;
    078        int result = 1;
    079        result = PRIME * result + descriptor.hashCode();
    080        result = PRIME * result + name.hashCode();
    081        cachedHashCode = result;
    082    }
    083
    084    @Override
    085    protected ClassFileEntry[] getNestedClassFileEntries() {
    086        return new ClassFileEntry[] { name, descriptor };
    087    }
    088
    089    @Override
    090    public int hashCode() {
    091        if (!hashCodeComputed) {
    092            generateHashCode();
    093        }
    094        return cachedHashCode;
    095    }
    096
    097    /**
    098     * Answers the invokeinterface count argument when the receiver is treated as an invokeinterface target. This value is not meaningful if the receiver is not
    099     * an invokeinterface target.
    100     *
    101     * @return count
    102     */
    103    public int invokeInterfaceCount() {
    104        return 1 + SegmentUtils.countInvokeInterfaceArgs(descriptor.underlyingString());
    105    }
    106
    107    @Override
    108    protected void resolve(final ClassConstantPool pool) {
    109        super.resolve(pool);
    110        descriptorIndex = pool.indexOf(descriptor);
    111        nameIndex = pool.indexOf(name);
    112    }
    113
    114    @Override
    115    public String toString() {
    116        return "NameAndType: " + name + "(" + descriptor + ")";
    117    }
    118
    119    @Override
    120    protected void writeBody(final DataOutputStream dos) throws IOException {
    121        dos.writeShort(nameIndex);
    122        dos.writeShort(descriptorIndex);
    123    }
    124}