001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     * http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    package org.apache.commons.compress.changes;
020    
021    import java.io.InputStream;
022    import java.util.Iterator;
023    import java.util.LinkedHashSet;
024    import java.util.Set;
025    
026    import org.apache.commons.compress.archivers.ArchiveEntry;
027    
028    /**
029     * ChangeSet collects and performs changes to an archive.
030     * Putting delete changes in this ChangeSet from multiple threads can
031     * cause conflicts.
032     * 
033     * @NotThreadSafe
034     */
035    public final class ChangeSet {
036    
037        private final Set changes = new LinkedHashSet();
038    
039        /**
040         * Deletes the file with the filename from the archive. 
041         * 
042         * @param filename
043         *            the filename of the file to delete
044         */
045        public void delete(final String filename) {
046            addDeletion(new Change(filename, Change.TYPE_DELETE));
047        }
048    
049        /**
050         * Deletes the directory tree from the archive. 
051         * 
052         * @param dirName
053         *            the name of the directory tree to delete
054         */
055        public void deleteDir(final String dirName) {
056            addDeletion(new Change(dirName, Change.TYPE_DELETE_DIR));
057        }
058        
059        /**
060         * Adds a new archive entry to the archive.
061         * 
062         * @param pEntry
063         *            the entry to add
064         * @param pInput
065         *            the datastream to add
066         */
067        public void add(final ArchiveEntry pEntry, final InputStream pInput) {
068            this.add(pEntry, pInput, true);
069        }
070        
071        /**
072         * Adds a new archive entry to the archive.
073         * If replace is set to true, this change will replace all other additions
074         * done in this ChangeSet and all existing entries in the original stream.
075         * 
076         * @param pEntry
077         *            the entry to add
078         * @param pInput
079         *            the datastream to add
080         * @param replace
081         *            indicates the this change should replace existing entries            
082         */
083        public void add(final ArchiveEntry pEntry, final InputStream pInput, final boolean replace) {
084            addAddition(new Change(pEntry, pInput, replace));
085        }
086    
087        /**
088         * Adds an addition change.
089         * 
090         * @param pChange
091         *            the change which should result in an addition
092         */
093        private void addAddition(Change pChange) {
094            if (Change.TYPE_ADD != pChange.type() ||    
095                pChange.getInput() == null) {
096                return;
097            }
098    
099            if (!changes.isEmpty()) {
100                for (Iterator it = changes.iterator(); it.hasNext();) {
101                    Change change = (Change) it.next();
102                    if (change.type() == Change.TYPE_ADD
103                            && change.getEntry() != null) {
104                        ArchiveEntry entry = change.getEntry();
105    
106                        if(entry.equals(pChange.getEntry())) {
107                            if(pChange.isReplaceMode()) {
108                                it.remove();
109                                changes.add(pChange);
110                                return;
111                            } else {
112                                // do not add this change
113                                return;
114                            }
115                        }
116                    }
117                }
118            }
119            changes.add(pChange);
120        }
121        
122        /**
123         * Adds an delete change.
124         * 
125         * @param pChange
126         *            the change which should result in a deletion
127         */
128        private void addDeletion(Change pChange) {
129            if ((Change.TYPE_DELETE != pChange.type() &&
130                Change.TYPE_DELETE_DIR != pChange.type()) ||    
131                pChange.targetFile() == null) {
132                return;
133            }
134            String source = pChange.targetFile();
135    
136            if (!changes.isEmpty()) {
137                for (Iterator it = changes.iterator(); it.hasNext();) {
138                    Change change = (Change) it.next();
139                    if (change.type() == Change.TYPE_ADD
140                            && change.getEntry() != null) {
141                        String target = change.getEntry().getName();
142    
143                        if (Change.TYPE_DELETE == pChange.type() && source.equals(target)) {
144                            it.remove();
145                        } else if (Change.TYPE_DELETE_DIR == pChange.type() && 
146                                   target.matches(source + "/.*")) {
147                            it.remove();
148                        }
149                    }
150                }
151            }
152            changes.add(pChange);
153        }
154    
155        /**
156         * Returns the list of changes as a copy. Changes on this set
157         * are not reflected on this ChangeSet and vice versa.
158         * @return the changes as a copy
159         */
160        Set getChanges() {
161            return new LinkedHashSet(changes);
162        }
163    }