components/keyed_service/content/refcounted_browser_context_keyed_service_factory.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 COMPONENTS_KEYED_SERVICE_CONTENT_REFCOUNTED_BROWSER_CONTEXT_KEYED_SERVICE_FACTORY_H_
   6 #define COMPONENTS_KEYED_SERVICE_CONTENT_REFCOUNTED_BROWSER_CONTEXT_KEYED_SERVICE_FACTORY_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/memory/ref_counted.h"
  11 #include "components/keyed_service/core/keyed_service_export.h"
  12 #include "components/keyed_service/core/refcounted_keyed_service_factory.h"
  13
  14 class BrowserContextDependencyManager;
  15 class RefcountedKeyedService;
  16
  17 namespace content {
  18 class BrowserContext;
  19 }
  20
  21 // A specialized BrowserContextKeyedServiceFactory that manages a
  22 // RefcountedThreadSafe<>.
  23 //
  24 // While the factory returns RefcountedThreadSafe<>s, the factory itself is a
  25 // base::NotThreadSafe. Only call methods on this object on the UI thread.
  26 //
  27 // Implementers of RefcountedKeyedService should note that we guarantee that
  28 // ShutdownOnUIThread() is called on the UI thread, but actual object
  29 // destruction can happen anywhere.
  30 class KEYED_SERVICE_EXPORT RefcountedBrowserContextKeyedServiceFactory
  31     : public RefcountedKeyedServiceFactory {
  32  public:
  33   // A function that supplies the instance of a KeyedService for a given
  34   // BrowserContext. This is used primarily for testing, where we want to feed
  35   // a specific mock into the BCKSF system.
  36   typedef scoped_refptr<RefcountedKeyedService>(*TestingFactoryFunction)(
  37       content::BrowserContext* context);
  38
  39   // Associates |factory| with |context| so that |factory| is used to create
  40   // the KeyedService when requested.  |factory| can be NULL to signal that
  41   // KeyedService should be NULL. Multiple calls to SetTestingFactory() are
  42   // allowed; previous services will be shut down.
  43   void SetTestingFactory(content::BrowserContext* context,
  44                          TestingFactoryFunction factory);
  45
  46   // Associates |factory| with |context| and immediately returns the created
  47   // KeyedService. Since the factory will be used immediately, it may not be
  48   // NULL.
  49   scoped_refptr<RefcountedKeyedService> SetTestingFactoryAndUse(
  50       content::BrowserContext* context,
  51       TestingFactoryFunction factory);
  52
  53  protected:
  54   // RefcountedBrowserContextKeyedServiceFactories must communicate with a
  55   // BrowserContextDependencyManager. For all non-test code, write your subclass
  56   // constructors like this:
  57   //
  58   //   MyServiceFactory::MyServiceFactory()
  59   //     : RefcountedBrowserContextKeyedServiceFactory(
  60   //         "MyService",
  61   //         BrowserContextDependencyManager::GetInstance())
  62   //   {}
  63   RefcountedBrowserContextKeyedServiceFactory(
  64       const char* name,
  65       BrowserContextDependencyManager* manager);
  66   ~RefcountedBrowserContextKeyedServiceFactory() override;
  67
  68   // Common implementation that maps |context| to some service object. Deals
  69   // with incognito contexts per subclass instructions with
  70   // GetBrowserContextRedirectedInIncognito() and
  71   // GetBrowserContextOwnInstanceInIncognito() through the
  72   // GetBrowserContextToUse() method on the base.  If |create| is true, the
  73   // service will be created using BuildServiceInstanceFor() if it doesn't
  74   // already exist.
  75   scoped_refptr<RefcountedKeyedService> GetServiceForBrowserContext(
  76       content::BrowserContext* context,
  77       bool create);
  78
  79   // Interface for people building a concrete FooServiceFactory: --------------
  80
  81   // Finds which browser context (if any) to use.
  82   virtual content::BrowserContext* GetBrowserContextToUse(
  83       content::BrowserContext* context) const;
  84
  85   // By default, we create instances of a service lazily and wait until
  86   // GetForBrowserContext() is called on our subclass. Some services need to be
  87   // created as soon as the BrowserContext has been brought up.
  88   virtual bool ServiceIsCreatedWithBrowserContext() const;
  89
  90   // By default, TestingBrowserContexts will be treated like normal contexts.
  91   // You can override this so that by default, the service associated with the
  92   // TestingBrowserContext is NULL. (This is just a shortcut around
  93   // SetTestingFactory() to make sure our contexts don't directly refer to the
  94   // services they use.)
  95   bool ServiceIsNULLWhileTesting() const override;
  96
  97   // Interface for people building a type of BrowserContextKeyedFactory: -------
  98
  99   // All subclasses of BrowserContextKeyedServiceFactory must return a
 100   // KeyedService instead of just a BrowserContextKeyedBase.
 101   virtual scoped_refptr<RefcountedKeyedService> BuildServiceInstanceFor(
 102       content::BrowserContext* context) const = 0;
 103
 104   // A helper object actually listens for notifications about BrowserContext
 105   // destruction, calculates the order in which things are destroyed and then
 106   // does a two pass shutdown.
 107   //
 108   // First, BrowserContextShutdown() is called on every ServiceFactory and will
 109   // usually call KeyedService::Shutdown(), which gives each
 110   // KeyedService a chance to remove dependencies on other
 111   // services that it may be holding.
 112   //
 113   // Secondly, BrowserContextDestroyed() is called on every ServiceFactory
 114   // and the default implementation removes it from |mapping_| and deletes
 115   // the pointer.
 116   virtual void BrowserContextShutdown(content::BrowserContext* context);
 117   virtual void BrowserContextDestroyed(content::BrowserContext* context);
 118
 119  private:
 120   friend class BrowserContextDependencyManagerUnittests;
 121
 122   // Registers any user preferences on this service. This is called by
 123   // RegisterPrefsIfNecessaryForContext() and should be overriden by any service
 124   // that wants to register profile-specific preferences.
 125   virtual void RegisterProfilePrefs(
 126       user_prefs::PrefRegistrySyncable* registry) {}
 127
 128   // RefcountedKeyedServiceFactory:
 129   scoped_refptr<RefcountedKeyedService> BuildServiceInstanceFor(
 130       base::SupportsUserData* context) const final;
 131   bool IsOffTheRecord(base::SupportsUserData* context) const final;
 132
 133   // KeyedServiceBaseFactory:
 134   base::SupportsUserData* GetContextToUse(
 135       base::SupportsUserData* context) const final;
 136   bool ServiceIsCreatedWithContext() const final;
 137   void ContextShutdown(base::SupportsUserData* context) final;
 138   void ContextDestroyed(base::SupportsUserData* context) final;
 139   void RegisterPrefs(user_prefs::PrefRegistrySyncable* registry) final;
 140
 141   DISALLOW_COPY_AND_ASSIGN(RefcountedBrowserContextKeyedServiceFactory);
 142 };
 143
 144 #endif  // COMPONENTS_KEYED_SERVICE_CONTENT_REFCOUNTED_BROWSER_CONTEXT_KEYED_SERVICE_FACTORY_H_