chrome/browser/extensions/extension_garbage_collector.h

   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
  16 namespace content {
  17 class BrowserContext;
  18 }
  19
  20 class ExtensionService;
  21
  22 namespace extensions {
  23
  24 // The class responsible for cleaning up the cruft left behind on the file
  25 // system by uninstalled (or failed install) extensions.
  26 // The class is owned by ExtensionService, but is mostly independent. Tasks to
  27 // garbage collect extensions and isolated storage are posted once the
  28 // ExtensionSystem signals ready.
  29 class ExtensionGarbageCollector : public KeyedService, public InstallObserver {
  30  public:
  31   explicit ExtensionGarbageCollector(content::BrowserContext* context);
  32   virtual ~ExtensionGarbageCollector();
  33
  34   static ExtensionGarbageCollector* Get(content::BrowserContext* context);
  35
  36 #if defined(OS_CHROMEOS)
  37   // Enable or disable garbage collection. See |disable_garbage_collection_|.
  38   void disable_garbage_collection() { disable_garbage_collection_ = true; }
  39   void enable_garbage_collection() { disable_garbage_collection_ = false; }
  40 #endif
  41
  42   // Manually trigger GarbageCollectExtensions() for testing.
  43   void GarbageCollectExtensionsForTest();
  44
  45   // Overriddes for KeyedService:
  46   virtual void Shutdown() OVERRIDE;
  47
  48   // Overriddes for InstallObserver
  49   virtual void OnBeginCrxInstall(const std::string& extension_id) OVERRIDE;
  50   virtual void OnFinishCrxInstall(const std::string& extension_id,
  51                                   bool success) OVERRIDE;
  52
  53  private:
  54   // Cleans up the extension install directory. It can end up with garbage in it
  55   // if extensions can't initially be removed when they are uninstalled (eg if a
  56   // file is in use).
  57   // Obsolete version directories are removed, as are directories that aren't
  58   // found in the ExtensionPrefs.
  59   // The "Temp" directory that is used during extension installation will get
  60   // removed iff there are no pending installations.
  61   void GarbageCollectExtensions();
  62
  63   // Garbage collects apps/extensions isolated storage if it is uninstalled.
  64   // There is an exception for ephemeral apps because they can outlive their
  65   // cache lifetimes.
  66   void GarbageCollectIsolatedStorageIfNeeded();
  67
  68   // The BrowserContext associated with the GarbageCollector.
  69   content::BrowserContext* context_;
  70
  71 #if defined(OS_CHROMEOS)
  72   // TODO(rkc): HACK alert - this is only in place to allow the
  73   // kiosk_mode_screensaver to prevent its extension from getting garbage
  74   // collected. Remove this once KioskModeScreensaver is removed.
  75   // See crbug.com/280363
  76   bool disable_garbage_collection_;
  77 #endif
  78
  79   // The number of currently ongoing CRX installations. This is used to prevent
  80   // garbage collection from running while a CRX is being installed.
  81   int crx_installs_in_progress_;
  82
  83   // Generate weak pointers for safely posting to the file thread for garbage
  84   // collection.
  85   base::WeakPtrFactory<ExtensionGarbageCollector> weak_factory_;
  86
  87   DISALLOW_COPY_AND_ASSIGN(ExtensionGarbageCollector);
  88 };
  89
  90 }  // namespace extensions
  91
  92 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_H_