    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 */
    019package org.apache.commons.compress.changes;
    020
    021import java.io.InputStream;
    022import java.util.Iterator;
    023import java.util.LinkedHashSet;
    024import java.util.Set;
    025
    026import 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 */
    035public final class ChangeSet {
    036
    037    private final Set<Change> changes = new LinkedHashSet<>();
    038
    039    /**
    040     * Adds a new archive entry to the archive.
    041     *
    042     * @param pEntry
    043     *            the entry to add
    044     * @param pInput
    045     *            the datastream to add
    046     */
    047    public void add(final ArchiveEntry pEntry, final InputStream pInput) {
    048        this.add(pEntry, pInput, true);
    049    }
    050
    051    /**
    052     * Adds a new archive entry to the archive.
    053     * If replace is set to true, this change will replace all other additions
    054     * done in this ChangeSet and all existing entries in the original stream.
    055     *
    056     * @param pEntry
    057     *            the entry to add
    058     * @param pInput
    059     *            the datastream to add
    060     * @param replace
    061     *            indicates the this change should replace existing entries
    062     */
    063    public void add(final ArchiveEntry pEntry, final InputStream pInput, final boolean replace) {
    064        addAddition(new Change(pEntry, pInput, replace));
    065    }
    066
    067    /**
    068     * Adds an addition change.
    069     *
    070     * @param pChange
    071     *            the change which should result in an addition
    072     */
    073    private void addAddition(final Change pChange) {
    074        if (Change.TYPE_ADD != pChange.type() ||
    075            pChange.getInput() == null) {
    076            return;
    077        }
    078
    079        if (!changes.isEmpty()) {
    080            for (final Iterator<Change> it = changes.iterator(); it.hasNext();) {
    081                final Change change = it.next();
    082                if (change.type() == Change.TYPE_ADD
    083                        && change.getEntry() != null) {
    084                    final ArchiveEntry entry = change.getEntry();
    085
    086                    if (entry.equals(pChange.getEntry())) {
    087                        if (pChange.isReplaceMode()) {
    088                            it.remove();
    089                            changes.add(pChange);
    090                        }
    091                        // do not add this change
    092                        return;
    093                    }
    094                }
    095            }
    096        }
    097        changes.add(pChange);
    098    }
    099
    100    /**
    101     * Adds an delete change.
    102     *
    103     * @param pChange
    104     *            the change which should result in a deletion
    105     */
    106    private void addDeletion(final Change pChange) {
    107        if ((Change.TYPE_DELETE != pChange.type() &&
    108            Change.TYPE_DELETE_DIR != pChange.type()) ||
    109            pChange.targetFile() == null) {
    110            return;
    111        }
    112        final String source = pChange.targetFile();
    113
    114        if (source != null && !changes.isEmpty()) {
    115            for (final Iterator<Change> it = changes.iterator(); it.hasNext();) {
    116                final Change change = it.next();
    117                if (change.type() == Change.TYPE_ADD
    118                        && change.getEntry() != null) {
    119                    final String target = change.getEntry().getName();
    120
    121                    if (target == null) {
    122                        continue;
    123                    }
    124
    125                    if (Change.TYPE_DELETE == pChange.type() && source.equals(target) ||
    126                            (Change.TYPE_DELETE_DIR == pChange.type() && target.matches(source + "/.*"))) {
    127                        it.remove();
    128                    }
    129                }
    130            }
    131        }
    132        changes.add(pChange);
    133    }
    134
    135    /**
    136     * Deletes the file with the file name from the archive.
    137     *
    138     * @param fileName
    139     *            the file name of the file to delete
    140     */
    141    public void delete(final String fileName) {
    142        addDeletion(new Change(fileName, Change.TYPE_DELETE));
    143    }
    144
    145    /**
    146     * Deletes the directory tree from the archive.
    147     *
    148     * @param dirName
    149     *            the name of the directory tree to delete
    150     */
    151    public void deleteDir(final String dirName) {
    152        addDeletion(new Change(dirName, Change.TYPE_DELETE_DIR));
    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<Change> getChanges() {
    161        return new LinkedHashSet<>(changes);
    162    }
    163}