copy_tree_work_item.h revision 5821806d5e7f356e8fa4b058a389a808ea183019 
1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CHROME_INSTALLER_UTIL_COPY_TREE_WORK_ITEM_H_
6#define CHROME_INSTALLER_UTIL_COPY_TREE_WORK_ITEM_H_
7
8#include "base/file_path.h"
9#include "base/gtest_prod_util.h"
10#include "base/scoped_temp_dir.h"
11#include "chrome/installer/util/work_item.h"
12
13// A WorkItem subclass that recursively copies a file system hierarchy from
14// source path to destination path. It also creates all necessary intermediate
15// paths of the destination path if they do not exist. The file system
16// hierarchy could be a single file, or a directory.
17// Under the cover CopyTreeWorkItem moves the destination path, if existing,
18// to the temporary directory passed in, and then copies the source hierarchy
19// to the destination location. During rollback the original destination
20// hierarchy is moved back.
21// NOTE: It is a best practice to ensure that the temporary directory is on the
22// same volume as the destination path.  If this is not the case, the existing
23// destination path is not moved, but rather copied, to the destination path.
24// This will result in in-use files being left behind, as well as potentially
25// losing ACLs or other metadata in the case of a rollback.
26class CopyTreeWorkItem : public WorkItem {
27 public:
28  virtual ~CopyTreeWorkItem();
29
30  virtual bool Do();
31
32  virtual void Rollback();
33
34 private:
35  friend class WorkItem;
36
37  // See comments on corresponding member variables for the semantics of
38  // arguments.
39  // Notes on temp_path: to facilitate rollback, the caller needs to supply
40  // a temporary directory to save the original files if they exist under
41  // dest_path.
42  CopyTreeWorkItem(const FilePath& source_path,
43                   const FilePath& dest_path,
44                   const FilePath& temp_dir,
45                   CopyOverWriteOption overwrite_option,
46                   const FilePath& alternative_path);
47
48  // Checks if the path specified is in use (and hence can not be deleted)
49  bool IsFileInUse(const FilePath& path);
50
51  // Source path to copy files from.
52  FilePath source_path_;
53
54  // Destination path to copy files to.
55  FilePath dest_path_;
56
57  // Temporary directory that can be used.
58  FilePath temp_dir_;
59
60  // Controls the behavior for overwriting.
61  CopyOverWriteOption overwrite_option_;
62
63  // If overwrite_option_ = NEW_NAME_IF_IN_USE, this variables stores the path
64  // to be used if the file is in use and hence we want to copy it to a
65  // different path.
66  FilePath alternative_path_;
67
68  // Whether the source was copied to dest_path_
69  bool copied_to_dest_path_;
70
71  // Whether the original files have been moved to backup path under
72  // temporary directory. If true, moving back is needed during rollback.
73  bool moved_to_backup_;
74
75  // Whether the source was copied to alternative_path_ because dest_path_
76  // existed and was in use. Needed during rollback.
77  bool copied_to_alternate_path_;
78
79  // The temporary directory into which the original dest_path_ has been moved.
80  ScopedTempDir backup_path_;
81
82  FRIEND_TEST_ALL_PREFIXES(CopyTreeWorkItemTest, CopyFileSameContent);
83  FRIEND_TEST_ALL_PREFIXES(CopyTreeWorkItemTest, CopyFileInUse);
84  FRIEND_TEST_ALL_PREFIXES(CopyTreeWorkItemTest, CopyFileAndCleanup);
85  FRIEND_TEST_ALL_PREFIXES(CopyTreeWorkItemTest, NewNameAndCopyTest);
86  FRIEND_TEST_ALL_PREFIXES(CopyTreeWorkItemTest, CopyFileInUseAndCleanup);
87};
88
89#endif  // CHROME_INSTALLER_UTIL_COPY_TREE_WORK_ITEM_H_
90