components/keyed_service/content/browser_context_keyed_base_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_BROWSER_CONTEXT_KEYED_BASE_FACTORY_H_
   6 #define COMPONENTS_KEYED_SERVICE_CONTENT_BROWSER_CONTEXT_KEYED_BASE_FACTORY_H_
   7
   8 #include <set>
   9
  10 #include "base/threading/non_thread_safe.h"
  11 #include "components/keyed_service/core/dependency_node.h"
  12 #include "components/keyed_service/core/keyed_service_export.h"
  13
  14 class BrowserContextDependencyManager;
  15 class PrefService;
  16
  17 namespace content {
  18 class BrowserContext;
  19 }
  20
  21 namespace user_prefs {
  22 class PrefRegistrySyncable;
  23 }
  24
  25 // Base class for Factories that take a BrowserContext object and return some
  26 // service.
  27 //
  28 // Unless you're trying to make a new type of Factory, you probably don't want
  29 // this class, but its subclasses: BrowserContextKeyedServiceFactory and
  30 // RefcountedBrowserContextKeyedServiceFactory. This object describes general
  31 // dependency management between Factories; subclasses react to lifecycle
  32 // events and implement memory management.
  33 class KEYED_SERVICE_EXPORT BrowserContextKeyedBaseFactory
  34     : public base::NonThreadSafe,
  35       NON_EXPORTED_BASE(public DependencyNode) {
  36  public:
  37   // Registers preferences used in this service on the pref service of
  38   // |context|. This is the public interface and is safe to be called multiple
  39   // times because testing code can have multiple services of the same type
  40   // attached to a single |context|. Only test code is allowed to call this
  41   // method.
  42   // TODO(gab): This method can be removed entirely when
  43   // PrefService::DeprecatedGetPrefRegistry() is phased out.
  44   void RegisterUserPrefsOnBrowserContextForTest(
  45       content::BrowserContext* context);
  46
  47 #ifndef NDEBUG
  48   // Returns our name. We don't keep track of this in release mode.
  49   const char* name() const { return service_name_; }
  50 #endif
  51
  52  protected:
  53   BrowserContextKeyedBaseFactory(const char* name,
  54                                  BrowserContextDependencyManager* manager);
  55   virtual ~BrowserContextKeyedBaseFactory();
  56
  57   // The main public interface for declaring dependencies between services
  58   // created by factories.
  59   void DependsOn(BrowserContextKeyedBaseFactory* rhs);
  60
  61   // Calls RegisterProfilePrefs() after doing house keeping required to work
  62   // alongside RegisterUserPrefsOnBrowserContextForTest().
  63   // TODO(gab): This method can be replaced by RegisterProfilePrefs() directly
  64   // once RegisterUserPrefsOnBrowserContextForTest() is phased out.
  65   void RegisterProfilePrefsIfNecessaryForContext(
  66       const content::BrowserContext* context,
  67       user_prefs::PrefRegistrySyncable* registry);
  68
  69   // Interface for people building a concrete FooServiceFactory: --------------
  70
  71   // Finds which browser context (if any) to use.
  72   virtual content::BrowserContext* GetBrowserContextToUse(
  73       content::BrowserContext* context) const;
  74
  75   // By default, we create instances of a service lazily and wait until
  76   // GetForBrowserContext() is called on our subclass. Some services need to be
  77   // created as soon as the BrowserContext has been brought up.
  78   virtual bool ServiceIsCreatedWithBrowserContext() const;
  79
  80   // By default, TestingBrowserContexts will be treated like normal contexts.
  81   // You can override this so that by default, the service associated with the
  82   // TestingBrowserContext is NULL. (This is just a shortcut around
  83   // SetTestingFactory() to make sure our contexts don't directly refer to the
  84   // services they use.)
  85   virtual bool ServiceIsNULLWhileTesting() const;
  86
  87   // Interface for people building a type of BrowserContextKeyedFactory: -------
  88
  89   // A helper object actually listens for notifications about BrowserContext
  90   // destruction, calculates the order in which things are destroyed and then
  91   // does a two pass shutdown.
  92   //
  93   // It is up to the individual factory types to determine what this two pass
  94   // shutdown means. The general framework guarantees the following:
  95   //
  96   // - Each BrowserContextShutdown() is called in dependency order (and you may
  97   //   reach out to other services during this phase).
  98   //
  99   // - Each BrowserContextDestroyed() is called in dependency order. We will
 100   //   NOTREACHED() if you attempt to GetForBrowserContext() any other service.
 101   //   You should delete/deref/do other final memory management things during
 102   //   this phase. You must also call the base class method as the last thing
 103   //   you do.
 104   virtual void BrowserContextShutdown(content::BrowserContext* context) = 0;
 105   virtual void BrowserContextDestroyed(content::BrowserContext* context);
 106
 107   // Returns whether we've registered the preferences on this context.
 108   bool ArePreferencesSetOn(content::BrowserContext* context) const;
 109
 110   // Mark context as Preferences set.
 111   void MarkPreferencesSetOn(content::BrowserContext* context);
 112
 113   // Which BrowserContextDependencyManager we should communicate with.
 114   // In real code, this will always be
 115   // BrowserContextDependencyManager::GetInstance(), but unit tests will want
 116   // to use their own copy.
 117   BrowserContextDependencyManager* dependency_manager_;
 118
 119  private:
 120   friend class BrowserContextDependencyManager;
 121   friend class BrowserContextDependencyManagerUnittests;
 122
 123   // Registers any user preferences on this service. This is called by
 124   // RegisterProfilePrefsIfNecessary() and should be overriden by any service
 125   // that wants to register profile-specific preferences.
 126   virtual void RegisterProfilePrefs(
 127       user_prefs::PrefRegistrySyncable* registry) {}
 128
 129   // These two methods are for tight integration with the
 130   // BrowserContextDependencyManager.
 131
 132   // Because of ServiceIsNULLWhileTesting(), we need a way to tell different
 133   // subclasses that they should disable testing.
 134   virtual void SetEmptyTestingFactory(content::BrowserContext* context) = 0;
 135
 136   // We also need a generalized, non-returning method that generates the object
 137   // now for when we're creating the context.
 138   virtual void CreateServiceNow(content::BrowserContext* context) = 0;
 139
 140   // BrowserContexts that have this service's preferences registered on them.
 141   std::set<const content::BrowserContext*> registered_preferences_;
 142
 143 #if !defined(NDEBUG)
 144   // A static string passed in to our constructor. Should be unique across all
 145   // services. This is used only for debugging in debug mode. (We can print
 146   // pretty graphs with GraphViz with this information.)
 147   const char* service_name_;
 148 #endif
 149 };
 150
 151 #endif  // COMPONENTS_KEYED_SERVICE_CONTENT_BROWSER_CONTEXT_KEYED_BASE_FACTORY_H_