1// Copyright 2014 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_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_H_
6#define CHROME_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_H_
7
8#include <map>
9#include <string>
10
11#include "base/files/file_path.h"
12#include "base/memory/weak_ptr.h"
13#include "chrome/browser/extensions/install_observer.h"
14#include "components/keyed_service/core/keyed_service.h"
15
16namespace content {
17class BrowserContext;
18}
19
20namespace extensions {
21
22// The class responsible for cleaning up the cruft left behind on the file
23// system by uninstalled (or failed install) extensions.
24// The class is owned by ExtensionService, but is mostly independent. Tasks to
25// garbage collect extensions and isolated storage are posted once the
26// ExtensionSystem signals ready.
27class ExtensionGarbageCollector : public KeyedService, public InstallObserver {
28 public:
29  explicit ExtensionGarbageCollector(content::BrowserContext* context);
30  virtual ~ExtensionGarbageCollector();
31
32  static ExtensionGarbageCollector* Get(content::BrowserContext* context);
33
34  // Manually trigger GarbageCollectExtensions() for testing.
35  void GarbageCollectExtensionsForTest();
36
37  // Overriddes for KeyedService:
38  virtual void Shutdown() OVERRIDE;
39
40  // Overriddes for InstallObserver
41  virtual void OnBeginCrxInstall(const std::string& extension_id) OVERRIDE;
42  virtual void OnFinishCrxInstall(const std::string& extension_id,
43                                  bool success) OVERRIDE;
44
45 protected:
46  // Cleans up the extension install directory. It can end up with garbage in it
47  // if extensions can't initially be removed when they are uninstalled (eg if a
48  // file is in use).
49  // Obsolete version directories are removed, as are directories that aren't
50  // found in the ExtensionPrefs.
51  // The "Temp" directory that is used during extension installation will get
52  // removed iff there are no pending installations.
53  virtual void GarbageCollectExtensions();
54
55  // Garbage collects apps/extensions isolated storage if it is uninstalled.
56  // There is an exception for ephemeral apps because they can outlive their
57  // cache lifetimes.
58  void GarbageCollectIsolatedStorageIfNeeded();
59
60  static void GarbageCollectExtensionsOnFileThread(
61      const base::FilePath& install_directory,
62      const std::multimap<std::string, base::FilePath>& extension_paths);
63
64  // The BrowserContext associated with the GarbageCollector.
65  content::BrowserContext* context_;
66
67  // The number of currently ongoing CRX installations. This is used to prevent
68  // garbage collection from running while a CRX is being installed.
69  int crx_installs_in_progress_;
70
71  // Generate weak pointers for safely posting to the file thread for garbage
72  // collection.
73  base::WeakPtrFactory<ExtensionGarbageCollector> weak_factory_;
74
75  DISALLOW_COPY_AND_ASSIGN(ExtensionGarbageCollector);
76};
77
78}  // namespace extensions
79
80#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_H_
81