    001/*
    002 *  Licensed to the Apache Software Foundation (ASF) under one or more
    003 *  contributor license agreements.  See the NOTICE file distributed with
    004 *  this work for additional information regarding copyright ownership.
    005 *  The ASF licenses this file to You under the Apache License, Version 2.0
    006 *  (the "License"); you may not use this file except in compliance with
    007 *  the License.  You may obtain a copy of the License at
    008 *
    009 *     http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 */
    017package org.apache.commons.compress.harmony.unpack200.bytecode;
    018
    019import java.io.DataOutputStream;
    020import java.io.IOException;
    021import java.util.Objects;
    022
    023import org.apache.commons.compress.harmony.unpack200.SegmentUtils;
    024
    025/**
    026 * Name and Type pair constant pool entry.
    027 */
    028public class CPNameAndType extends ConstantPoolEntry {
    029
    030    CPUTF8 descriptor;
    031
    032    transient int descriptorIndex;
    033
    034    CPUTF8 name;
    035
    036    transient int nameIndex;
    037
    038    private boolean hashCodeComputed;
    039
    040    private int cachedHashCode;
    041
    042    /**
    043     * Constructs a new CPNameAndType.
    044     *
    045     * @param name        TODO
    046     * @param descriptor  TODO
    047     * @param globalIndex index in CpBands
    048     * @throws NullPointerException if name or descriptor is null
    049     */
    050    public CPNameAndType(final CPUTF8 name, final CPUTF8 descriptor, final int globalIndex) {
    051        super(CP_NameAndType, globalIndex);
    052        this.name = Objects.requireNonNull(name, "name");
    053        this.descriptor = Objects.requireNonNull(descriptor, "descriptor");
    054    }
    055
    056    /*
    057     * field_info { u2 access_flags; u2 name_index; u2 descriptor_index; u2 attributes_count; attribute_info attributes[attributes_count]; }
    058     */
    059
    060    @Override
    061    public boolean equals(final Object obj) {
    062        if (this == obj) {
    063            return true;
    064        }
    065        if (obj == null) {
    066            return false;
    067        }
    068        if (getClass() != obj.getClass()) {
    069            return false;
    070        }
    071        final CPNameAndType other = (CPNameAndType) obj;
    072        return Objects.equals(descriptor, other.descriptor)
    073                && Objects.equals(name, other.name);
    074    }
    075
    076    private void generateHashCode() {
    077        hashCodeComputed = true;
    078        final int PRIME = 31;
    079        int result = 1;
    080        result = PRIME * result + descriptor.hashCode();
    081        result = PRIME * result + name.hashCode();
    082        cachedHashCode = result;
    083    }
    084
    085    @Override
    086    protected ClassFileEntry[] getNestedClassFileEntries() {
    087        return new ClassFileEntry[] { name, descriptor };
    088    }
    089
    090    @Override
    091    public int hashCode() {
    092        if (!hashCodeComputed) {
    093            generateHashCode();
    094        }
    095        return cachedHashCode;
    096    }
    097
    098    /**
    099     * Answers the invokeinterface count argument when the receiver is treated as an invokeinterface target. This value is not meaningful if the receiver is not
    100     * an invokeinterface target.
    101     *
    102     * @return count
    103     */
    104    public int invokeInterfaceCount() {
    105        return 1 + SegmentUtils.countInvokeInterfaceArgs(descriptor.underlyingString());
    106    }
    107
    108    @Override
    109    protected void resolve(final ClassConstantPool pool) {
    110        super.resolve(pool);
    111        descriptorIndex = pool.indexOf(descriptor);
    112        nameIndex = pool.indexOf(name);
    113    }
    114
    115    @Override
    116    public String toString() {
    117        return "NameAndType: " + name + "(" + descriptor + ")";
    118    }
    119
    120    @Override
    121    protected void writeBody(final DataOutputStream dos) throws IOException {
    122        dos.writeShort(nameIndex);
    123        dos.writeShort(descriptorIndex);
    124    }
    125}