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;
018
019import java.io.IOException;
020import java.io.InputStream;
021import java.util.ArrayList;
022import java.util.HashMap;
023import java.util.HashSet;
024import java.util.List;
025import java.util.Map;
026import java.util.Set;
027
028import org.apache.commons.compress.harmony.pack200.Codec;
029import org.apache.commons.compress.harmony.pack200.Pack200Exception;
030import org.apache.commons.compress.harmony.unpack200.bytecode.CPClass;
031import org.apache.commons.compress.harmony.unpack200.bytecode.ClassConstantPool;
032import org.apache.commons.compress.harmony.unpack200.bytecode.ClassFileEntry;
033import org.apache.commons.compress.harmony.unpack200.bytecode.ConstantPoolEntry;
034
035/**
036 * Inner Class Bands
037 */
038public class IcBands extends BandSet {
039
040    private IcTuple[] icAll;
041
042    private final String[] cpUTF8;
043
044    private final String[] cpClass;
045
046    private Map<String, IcTuple> thisClassToTuple;
047    private Map<String, List<IcTuple>> outerClassToTuples;
048
049    /**
050     * @param segment TODO
051     */
052    public IcBands(final Segment segment) {
053        super(segment);
054        this.cpClass = segment.getCpBands().getCpClass();
055        this.cpUTF8 = segment.getCpBands().getCpUTF8();
056    }
057
058    /*
059     * (non-Javadoc)
060     *
061     * @see org.apache.commons.compress.harmony.unpack200.BandSet#unpack(java.io.InputStream)
062     */
063    @Override
064    public void read(final InputStream in) throws IOException, Pack200Exception {
065        // Read IC bands
066        final int innerClassCount = header.getInnerClassCount();
067        final int[] icThisClassInts = decodeBandInt("ic_this_class", in, Codec.UDELTA5, innerClassCount);
068        final String[] icThisClass = getReferences(icThisClassInts, cpClass);
069        final int[] icFlags = decodeBandInt("ic_flags", in, Codec.UNSIGNED5, innerClassCount);
070        final int outerClasses = SegmentUtils.countBit16(icFlags);
071        final int[] icOuterClassInts = decodeBandInt("ic_outer_class", in, Codec.DELTA5, outerClasses);
072        final String[] icOuterClass = new String[outerClasses];
073        for (int i = 0; i < icOuterClass.length; i++) {
074            if (icOuterClassInts[i] == 0) {
075                icOuterClass[i] = null;
076            } else {
077                icOuterClass[i] = cpClass[icOuterClassInts[i] - 1];
078            }
079        }
080        final int[] icNameInts = decodeBandInt("ic_name", in, Codec.DELTA5, outerClasses);
081        final String[] icName = new String[outerClasses];
082        for (int i = 0; i < icName.length; i++) {
083            if (icNameInts[i] == 0) {
084                icName[i] = null;
085            } else {
086                icName[i] = cpUTF8[icNameInts[i] - 1];
087            }
088        }
089
090        // Construct IC tuples
091        icAll = new IcTuple[icThisClass.length];
092        int index = 0;
093        for (int i = 0; i < icThisClass.length; i++) {
094            final String icTupleC = icThisClass[i];
095            final int icTupleF = icFlags[i];
096            String icTupleC2 = null;
097            String icTupleN = null;
098            final int cIndex = icThisClassInts[i];
099            int c2Index = -1;
100            int nIndex = -1;
101            if ((icFlags[i] & 1 << 16) != 0) {
102                icTupleC2 = icOuterClass[index];
103                icTupleN = icName[index];
104                c2Index = icOuterClassInts[index] - 1;
105                nIndex = icNameInts[index] - 1;
106                index++;
107            }
108            icAll[i] = new IcTuple(icTupleC, icTupleF, icTupleC2, icTupleN, cIndex, c2Index, nIndex, i);
109        }
110    }
111
112    @Override
113    public void unpack() throws IOException, Pack200Exception {
114        final IcTuple[] allTuples = getIcTuples();
115        thisClassToTuple = new HashMap<>(allTuples.length);
116        outerClassToTuples = new HashMap<>(allTuples.length);
117        for (final IcTuple tuple : allTuples) {
118
119            // generate mapping thisClassString -> IcTuple
120            // presumably this relation is 1:1
121            //
122            final Object result = thisClassToTuple.put(tuple.thisClassString(), tuple);
123            if (result != null) {
124                throw new Error("Collision detected in <thisClassString, IcTuple> mapping. "
125                    + "There are at least two inner clases with the same name.");
126            }
127
128            // generate mapping outerClassString -> IcTuple
129            // this relation is 1:M
130
131            // If it's not anon and the outer is not anon, it could be relevant
132            if ((!tuple.isAnonymous() && !tuple.outerIsAnonymous()) || (tuple.nestedExplicitFlagSet())) {
133
134                // add tuple to corresponding bucket
135                final String key = tuple.outerClassString();
136                List<IcTuple> bucket = outerClassToTuples.get(key);
137                if (bucket == null) {
138                    bucket = new ArrayList<>();
139                    outerClassToTuples.put(key, bucket);
140                }
141                bucket.add(tuple);
142            }
143        }
144    }
145
146    public IcTuple[] getIcTuples() {
147        return icAll;
148    }
149
150    /**
151     * Answer the relevant IcTuples for the specified className and class constant pool.
152     *
153     * @param className String name of the class X for ic_relevant(X)
154     * @param cp ClassConstantPool used to generate ic_relevant(X)
155     * @return array of IcTuple
156     */
157    public IcTuple[] getRelevantIcTuples(final String className, final ClassConstantPool cp) {
158        final Set<IcTuple> relevantTuplesContains = new HashSet<>();
159        final List<IcTuple> relevantTuples = new ArrayList<>();
160
161        final List<IcTuple> relevantCandidates = outerClassToTuples.get(className);
162        if (relevantCandidates != null) {
163            for (int index = 0; index < relevantCandidates.size(); index++) {
164                final IcTuple tuple = relevantCandidates.get(index);
165                relevantTuplesContains.add(tuple);
166                relevantTuples.add(tuple);
167            }
168        }
169
170        final List<ClassFileEntry> entries = cp.entries();
171
172        // For every class constant in both ic_this_class and cp,
173        // add it to ic_relevant. Repeat until no more
174        // changes to ic_relevant.
175
176        for (int eIndex = 0; eIndex < entries.size(); eIndex++) {
177            final ConstantPoolEntry entry = (ConstantPoolEntry) entries.get(eIndex);
178            if (entry instanceof CPClass) {
179                final CPClass clazz = (CPClass) entry;
180                final IcTuple relevant = thisClassToTuple.get(clazz.name);
181                if (relevant != null && relevantTuplesContains.add(relevant)) {
182                    relevantTuples.add(relevant);
183                }
184            }
185        }
186
187        // Not part of spec: fix up by adding to relevantTuples the parents
188        // of inner classes which are themselves inner classes.
189        // i.e., I think that if Foo$Bar$Baz gets added, Foo$Bar needs to be
190        // added
191        // as well.
192
193        final List<IcTuple> tuplesToScan = new ArrayList<>(relevantTuples);
194        final List<IcTuple> tuplesToAdd = new ArrayList<>();
195
196        while (tuplesToScan.size() > 0) {
197
198            tuplesToAdd.clear();
199            for (int index = 0; index < tuplesToScan.size(); index++) {
200                final IcTuple aRelevantTuple = tuplesToScan.get(index);
201                final IcTuple relevant = thisClassToTuple.get(aRelevantTuple.outerClassString());
202                if (relevant != null && !aRelevantTuple.outerIsAnonymous()) {
203                    tuplesToAdd.add(relevant);
204                }
205            }
206
207            tuplesToScan.clear();
208            for (int index = 0; index < tuplesToAdd.size(); index++) {
209                final IcTuple tuple = tuplesToAdd.get(index);
210                if (relevantTuplesContains.add(tuple)) {
211                    relevantTuples.add(tuple);
212                    tuplesToScan.add(tuple);
213                }
214            }
215
216        }
217
218        // End not part of the spec. Ugh.
219
220        // Now order the result as a subsequence of ic_all
221        relevantTuples.sort((arg0, arg1) -> {
222            final Integer index1 = Integer.valueOf(arg0.getTupleIndex());
223            final Integer index2 = Integer.valueOf(arg1.getTupleIndex());
224            return index1.compareTo(index2);
225        });
226
227        return relevantTuples.toArray(IcTuple.EMPTY_ARRAY);
228    }
229
230}