Move files instead of copying them.

chrome/installer/util/move_tree_work_item.h

+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_INSTALLER_UTIL_MOVE_TREE_WORK_ITEM_H_
+#define CHROME_INSTALLER_UTIL_MOVE_TREE_WORK_ITEM_H_
+
+#include <string>
+#include <windows.h>
+
+#include "chrome/installer/util/work_item.h"
+
+// A WorkItem subclass that recursively move a file system hierarchy from
+// source path to destination path. The file system hierarchy could be a
+// single file, or a directory.
+//
+// Under the cover MoveTreeWorkItem moves the destination path, if existing,
+// to the temporary directory passed in, and then moves the source hierarchy
+// to the destination location. During rollback the original destination
+// hierarchy is moved back.
+class MoveTreeWorkItem : public WorkItem {
+ public:
+  virtual ~MoveTreeWorkItem();
+
+  virtual bool Do();
+
+  virtual void Rollback();
+
+ private:
+  friend class WorkItem;
+
+  // source_path specifies file or directory that will be moved to location
+  // specified by dest_path. To facilitate rollback, the caller needs to supply
+  // a temporary directory (temp_dir) to save the original files if they exist
+  // under dest_path.
+  MoveTreeWorkItem(const std::wstring& source_path,
+                   const std::wstring& dest_path,
+                   const std::wstring& temp_dir);
+
+  // Source path to move files from.
+  std::wstring source_path_;
+
+  // Destination path to move files to.
+  std::wstring dest_path_;
+
+  // Temporary directory to backup dest_path_ (if it already exists).
+  std::wstring temp_dir_;
+
+  // The full path in temp_dir_ where the original dest_path_ has
+  // been moved to.
+  std::wstring backup_path_;
+
+  // Whether the source was moved to dest_path_
+  bool moved_to_dest_path_;
+
+  // Whether the original files have been moved to backup path under
+  // temporary directory. If true, moving back is needed during rollback.
+  bool moved_to_backup_;
+};
+
+#endif  // CHROME_INSTALLER_UTIL_MOVE_TREE_WORK_ITEM_H_
+