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;
021
022import org.apache.commons.compress.harmony.unpack200.SegmentUtils;
023
024/**
025 * Name and Type pair constant pool entry.
026 */
027public class CPNameAndType extends ConstantPoolEntry {
028
029    CPUTF8 descriptor;
030
031    transient int descriptorIndex;
032
033    CPUTF8 name;
034
035    transient int nameIndex;
036
037    /**
038     * Create a new CPNameAndType
039     *
040     * @param name TODO
041     * @param descriptor TODO
042     * @param globalIndex - index in CpBands
043     * @throws NullPointerException if name or descriptor is null
044     */
045    public CPNameAndType(final CPUTF8 name, final CPUTF8 descriptor, final int globalIndex) {
046        super(ConstantPoolEntry.CP_NameAndType, globalIndex);
047        this.name = name;
048        this.descriptor = descriptor;
049        if (name == null || descriptor == null) {
050            throw new NullPointerException("Null arguments are not allowed");
051        }
052    }
053
054    @Override
055    protected ClassFileEntry[] getNestedClassFileEntries() {
056        return new ClassFileEntry[] {name, descriptor};
057    }
058
059    @Override
060    protected void resolve(final ClassConstantPool pool) {
061        super.resolve(pool);
062        descriptorIndex = pool.indexOf(descriptor);
063        nameIndex = pool.indexOf(name);
064    }
065
066    /*
067     * field_info { u2 access_flags; u2 name_index; u2 descriptor_index; u2 attributes_count; attribute_info
068     * attributes[attributes_count]; }
069     */
070
071    @Override
072    protected void writeBody(final DataOutputStream dos) throws IOException {
073        dos.writeShort(nameIndex);
074        dos.writeShort(descriptorIndex);
075    }
076
077    @Override
078    public String toString() {
079        return "NameAndType: " + name + "(" + descriptor + ")";
080    }
081
082    private boolean hashcodeComputed;
083    private int cachedHashCode;
084
085    private void generateHashCode() {
086        hashcodeComputed = true;
087        final int PRIME = 31;
088        int result = 1;
089        result = PRIME * result + descriptor.hashCode();
090        result = PRIME * result + name.hashCode();
091        cachedHashCode = result;
092    }
093
094    @Override
095    public int hashCode() {
096        if (!hashcodeComputed) {
097            generateHashCode();
098        }
099        return cachedHashCode;
100    }
101
102    @Override
103    public boolean equals(final Object obj) {
104        if (this == obj) {
105            return true;
106        }
107        if (obj == null) {
108            return false;
109        }
110        if (getClass() != obj.getClass()) {
111            return false;
112        }
113        final CPNameAndType other = (CPNameAndType) obj;
114        if (!descriptor.equals(other.descriptor)) {
115            return false;
116        }
117        if (!name.equals(other.name)) {
118            return false;
119        }
120        return true;
121    }
122
123    /**
124     * Answers the invokeinterface count argument when the receiver is treated as an invokeinterface target. This value
125     * is not meaningful if the receiver is not an invokeinterface target.
126     *
127     * @return count
128     */
129    public int invokeInterfaceCount() {
130        return 1 + SegmentUtils.countInvokeInterfaceArgs(descriptor.underlyingString());
131    }
132}