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(ConstantPoolEntry.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        if (!descriptor.equals(other.descriptor)) {
073            return false;
074        }
075        if (!name.equals(other.name)) {
076            return false;
077        }
078        return true;
079    }
080
081    private void generateHashCode() {
082        hashCodeComputed = true;
083        final int PRIME = 31;
084        int result = 1;
085        result = PRIME * result + descriptor.hashCode();
086        result = PRIME * result + name.hashCode();
087        cachedHashCode = result;
088    }
089
090    @Override
091    protected ClassFileEntry[] getNestedClassFileEntries() {
092        return new ClassFileEntry[] { name, descriptor };
093    }
094
095    @Override
096    public int hashCode() {
097        if (!hashCodeComputed) {
098            generateHashCode();
099        }
100        return cachedHashCode;
101    }
102
103    /**
104     * Answers the invokeinterface count argument when the receiver is treated as an invokeinterface target. This value is not meaningful if the receiver is not
105     * an invokeinterface target.
106     *
107     * @return count
108     */
109    public int invokeInterfaceCount() {
110        return 1 + SegmentUtils.countInvokeInterfaceArgs(descriptor.underlyingString());
111    }
112
113    @Override
114    protected void resolve(final ClassConstantPool pool) {
115        super.resolve(pool);
116        descriptorIndex = pool.indexOf(descriptor);
117        nameIndex = pool.indexOf(name);
118    }
119
120    @Override
121    public String toString() {
122        return "NameAndType: " + name + "(" + descriptor + ")";
123    }
124
125    @Override
126    protected void writeBody(final DataOutputStream dos) throws IOException {
127        dos.writeShort(nameIndex);
128        dos.writeShort(descriptorIndex);
129    }
130}