components/keyed_service/ios/refcounted_browser_state_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_IOS_REFCOUNTED_BROWSER_STATE_KEYED_SERVICE_FACTORY_H_
   6 #define COMPONENTS_KEYED_SERVICE_IOS_REFCOUNTED_BROWSER_STATE_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 BrowserStateDependencyManager;
  15 class RefcountedKeyedService;
  16
  17 namespace web {
  18 class BrowserState;
  19 }
  20
  21 // A specialized BrowserStateKeyedServiceFactory 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 RefcountedBrowserStateKeyedServiceFactory
  31     : public RefcountedKeyedServiceFactory {
  32  public:
  33   // A function that supplies the instance of a KeyedService for a given
  34   // BrowserState. This is used primarily for testing, where we want to feed
  35   // a specific mock into the BSKSF system.
  36   typedef scoped_refptr<RefcountedKeyedService>(*TestingFactoryFunction)(
  37       web::BrowserState* 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(web::BrowserState* 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       web::BrowserState* context,
  51       TestingFactoryFunction factory);
  52
  53  protected:
  54   // RefcountedBrowserStateKeyedServiceFactories must communicate with a
  55   // BrowserStateDependencyManager. For all non-test code, write your subclass
  56   // constructors like this:
  57   //
  58   //   MyServiceFactory::MyServiceFactory()
  59   //     : RefcountedBrowserStateKeyedServiceFactory(
  60   //         "MyService",
  61   //         BrowserStateDependencyManager::GetInstance()) {
  62   //   }
  63   RefcountedBrowserStateKeyedServiceFactory(
  64       const char* name,
  65       /*BrowserState*/DependencyManager* manager);
  66   ~RefcountedBrowserStateKeyedServiceFactory() override;
  67
  68   // Common implementation that maps |context| to some service object. Deals
  69   // with incognito and testing contexts per subclass instructions. If |create|
  70   // is true, the service will be created using BuildServiceInstanceFor() if it
  71   // doesn't already exist.
  72   scoped_refptr<RefcountedKeyedService> GetServiceForBrowserState(
  73       web::BrowserState* context,
  74       bool create);
  75
  76   // Interface for people building a concrete FooServiceFactory: --------------
  77
  78   // Finds which browser state (if any) to use.
  79   virtual web::BrowserState* GetBrowserStateToUse(
  80       web::BrowserState* context) const;
  81
  82   // By default, we create instances of a service lazily and wait until
  83   // GetForBrowserState() is called on our subclass. Some services need to be
  84   // created as soon as the BrowserState has been brought up.
  85   virtual bool ServiceIsCreatedWithBrowserState() const;
  86
  87   // By default, TestingBrowserStates will be treated like normal contexts.
  88   // You can override this so that by default, the service associated with the
  89   // TestingBrowserState is NULL. (This is just a shortcut around
  90   // SetTestingFactory() to make sure our contexts don't directly refer to the
  91   // services they use.)
  92   bool ServiceIsNULLWhileTesting() const override;
  93
  94   // Interface for people building a type of BrowserStateKeyedFactory: -------
  95
  96   // All subclasses of BrowserStateKeyedServiceFactory must return a
  97   // KeyedService instead of just a BrowserStateKeyedBase.
  98   virtual scoped_refptr<RefcountedKeyedService> BuildServiceInstanceFor(
  99       web::BrowserState* context) const = 0;
 100
 101   // A helper object actually listens for notifications about BrowserState
 102   // destruction, calculates the order in which things are destroyed and then
 103   // does a two pass shutdown.
 104   //
 105   // First, BrowserStateShutdown() is called on every ServiceFactory and will
 106   // usually call KeyedService::Shutdown(), which gives each
 107   // KeyedService a chance to remove dependencies on other
 108   // services that it may be holding.
 109   //
 110   // Secondly, BrowserStateDestroyed() is called on every ServiceFactory
 111   // and the default implementation removes it from |mapping_| and deletes
 112   // the pointer.
 113   virtual void BrowserStateShutdown(web::BrowserState* context);
 114   virtual void BrowserStateDestroyed(web::BrowserState* context);
 115
 116  private:
 117   // Registers any user preferences on this service. This is called by
 118   // RegisterProfilePrefsIfNecessary() and should be overriden by any service
 119   // that wants to register profile-specific preferences.
 120   virtual void RegisterProfilePrefs(
 121       user_prefs::PrefRegistrySyncable* registry) {}
 122
 123   // RefcountedKeyedServiceFactory:
 124   scoped_refptr<RefcountedKeyedService> BuildServiceInstanceFor(
 125       base::SupportsUserData* context) const final;
 126   bool IsOffTheRecord(base::SupportsUserData* context) const final;
 127
 128   // KeyedServiceBaseFactory:
 129   user_prefs::PrefRegistrySyncable* GetAssociatedPrefRegistry(
 130       base::SupportsUserData* context) const final;
 131   base::SupportsUserData* GetContextToUse(
 132       base::SupportsUserData* context) const final;
 133   bool ServiceIsCreatedWithContext() const final;
 134   void ContextShutdown(base::SupportsUserData* context) final;
 135   void ContextDestroyed(base::SupportsUserData* context) final;
 136   void RegisterPrefs(user_prefs::PrefRegistrySyncable* registry) final;
 137
 138   DISALLOW_COPY_AND_ASSIGN(RefcountedBrowserStateKeyedServiceFactory);
 139 };
 140
 141 #endif  // COMPONENTS_KEYED_SERVICE_IOS_REFCOUNTED_BROWSER_STATE_KEYED_SERVICE_FACTORY_H_