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