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     * Create 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
058     * attributes[attributes_count]; }
059     */
060
061    @Override
062    public boolean equals(final Object obj) {
063        if (this == obj) {
064            return true;
065        }
066        if (obj == null) {
067            return false;
068        }
069        if (getClass() != obj.getClass()) {
070            return false;
071        }
072        final CPNameAndType other = (CPNameAndType) obj;
073        if (!descriptor.equals(other.descriptor)) {
074            return false;
075        }
076        if (!name.equals(other.name)) {
077            return false;
078        }
079        return true;
080    }
081
082    private void generateHashCode() {
083        hashCodeComputed = true;
084        final int PRIME = 31;
085        int result = 1;
086        result = PRIME * result + descriptor.hashCode();
087        result = PRIME * result + name.hashCode();
088        cachedHashCode = result;
089    }
090
091    @Override
092    protected ClassFileEntry[] getNestedClassFileEntries() {
093        return new ClassFileEntry[] {name, descriptor};
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
105     * is not meaningful if the receiver is not 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}