1 files changed, 164 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/compress/changes/ChangeSet.java b/src/main/java/org/apache/commons/compress/changes/ChangeSet.java
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+++ b/src/main/java/org/apache/commons/compress/changes/ChangeSet.java
@@ -0,0 +1,164 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.commons.compress.changes;
+
+import java.io.InputStream;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import org.apache.commons.compress.archivers.ArchiveEntry;
+
+/**
+ * ChangeSet collects and performs changes to an archive.
+ * Putting delete changes in this ChangeSet from multiple threads can
+ * cause conflicts.
+ *
+ * @NotThreadSafe
+ */
+public final class ChangeSet {
+
+    private final Set<Change> changes = new LinkedHashSet<>();
+
+    /**
+     * Deletes the file with the filename from the archive.
+     *
+     * @param filename
+     *            the filename of the file to delete
+     */
+    public void delete(final String filename) {
+        addDeletion(new Change(filename, Change.TYPE_DELETE));
+    }
+
+    /**
+     * Deletes the directory tree from the archive.
+     *
+     * @param dirName
+     *            the name of the directory tree to delete
+     */
+    public void deleteDir(final String dirName) {
+        addDeletion(new Change(dirName, Change.TYPE_DELETE_DIR));
+    }
+
+    /**
+     * Adds a new archive entry to the archive.
+     *
+     * @param pEntry
+     *            the entry to add
+     * @param pInput
+     *            the datastream to add
+     */
+    public void add(final ArchiveEntry pEntry, final InputStream pInput) {
+        this.add(pEntry, pInput, true);
+    }
+
+    /**
+     * Adds a new archive entry to the archive.
+     * If replace is set to true, this change will replace all other additions
+     * done in this ChangeSet and all existing entries in the original stream.
+     *
+     * @param pEntry
+     *            the entry to add
+     * @param pInput
+     *            the datastream to add
+     * @param replace
+     *            indicates the this change should replace existing entries
+     */
+    public void add(final ArchiveEntry pEntry, final InputStream pInput, final boolean replace) {
+        addAddition(new Change(pEntry, pInput, replace));
+    }
+
+    /**
+     * Adds an addition change.
+     *
+     * @param pChange
+     *            the change which should result in an addition
+     */
+    private void addAddition(final Change pChange) {
+        if (Change.TYPE_ADD != pChange.type() ||
+            pChange.getInput() == null) {
+            return;
+        }
+
+        if (!changes.isEmpty()) {
+            for (final Iterator<Change> it = changes.iterator(); it.hasNext();) {
+                final Change change = it.next();
+                if (change.type() == Change.TYPE_ADD
+                        && change.getEntry() != null) {
+                    final ArchiveEntry entry = change.getEntry();
+
+                    if(entry.equals(pChange.getEntry())) {
+                        if(pChange.isReplaceMode()) {
+                            it.remove();
+                            changes.add(pChange);
+                            return;
+                        }
+                        // do not add this change
+                        return;
+                    }
+                }
+            }
+        }
+        changes.add(pChange);
+    }
+
+    /**
+     * Adds an delete change.
+     *
+     * @param pChange
+     *            the change which should result in a deletion
+     */
+    private void addDeletion(final Change pChange) {
+        if ((Change.TYPE_DELETE != pChange.type() &&
+            Change.TYPE_DELETE_DIR != pChange.type()) ||
+            pChange.targetFile() == null) {
+            return;
+        }
+        final String source = pChange.targetFile();
+
+        if (source != null && !changes.isEmpty()) {
+            for (final Iterator<Change> it = changes.iterator(); it.hasNext();) {
+                final Change change = it.next();
+                if (change.type() == Change.TYPE_ADD
+                        && change.getEntry() != null) {
+                    final String target = change.getEntry().getName();
+
+                    if (target == null) {
+                        continue;
+                    }
+
+                    if (Change.TYPE_DELETE == pChange.type() && source.equals(target) ||
+                            (Change.TYPE_DELETE_DIR == pChange.type() && target.matches(source + "/.*"))) {
+                        it.remove();
+                    }
+                }
+            }
+        }
+        changes.add(pChange);
+    }
+
+    /**
+     * Returns the list of changes as a copy. Changes on this set
+     * are not reflected on this ChangeSet and vice versa.
+     * @return the changes as a copy
+     */
+    Set<Change> getChanges() {
+        return new LinkedHashSet<>(changes);
+    }
+}