components/keyed_service/content/browser_context_dependency_manager.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_DEPENDENCY_MANAGER_H_
   6 #define COMPONENTS_KEYED_SERVICE_CONTENT_BROWSER_CONTEXT_DEPENDENCY_MANAGER_H_
   7
   8 #include "base/callback_forward.h"
   9 #include "base/callback_list.h"
  10 #include "base/memory/singleton.h"
  11 #include "components/keyed_service/core/dependency_graph.h"
  12 #include "components/keyed_service/core/keyed_service_export.h"
  13
  14 #ifndef NDEBUG
  15 #include <set>
  16 #endif
  17
  18 class BrowserContextKeyedBaseFactory;
  19
  20 namespace content {
  21 class BrowserContext;
  22 }
  23
  24 namespace user_prefs {
  25 class PrefRegistrySyncable;
  26 }
  27
  28 // A singleton that listens for context destruction notifications and
  29 // rebroadcasts them to each BrowserContextKeyedBaseFactory in a safe order
  30 // based on the stated dependencies by each service.
  31 class KEYED_SERVICE_EXPORT BrowserContextDependencyManager {
  32  public:
  33   // Adds/Removes a component from our list of live components. Removing will
  34   // also remove live dependency links.
  35   void AddComponent(BrowserContextKeyedBaseFactory* component);
  36   void RemoveComponent(BrowserContextKeyedBaseFactory* component);
  37
  38   // Adds a dependency between two factories.
  39   void AddEdge(BrowserContextKeyedBaseFactory* depended,
  40                BrowserContextKeyedBaseFactory* dependee);
  41
  42   // Registers profile-specific preferences for all services via |registry|.
  43   // |context| should be the BrowserContext containing |registry| and is used as
  44   // a key to prevent multiple registrations on the same BrowserContext in
  45   // tests.
  46   void RegisterProfilePrefsForServices(
  47       const content::BrowserContext* context,
  48       user_prefs::PrefRegistrySyncable* registry);
  49
  50   // Called by each BrowserContext to alert us of its creation. Several
  51   // services want to be started when a context is created. If you want your
  52   // KeyedService to be started with the BrowserContext, override
  53   // BrowserContextKeyedBaseFactory::ServiceIsCreatedWithBrowserContext() to
  54   // return true. This method also registers any service-related preferences
  55   // for non-incognito profiles.
  56   void CreateBrowserContextServices(content::BrowserContext* context);
  57
  58   // Similar to CreateBrowserContextServices(), except this is used for creating
  59   // test BrowserContexts - these contexts will not create services for any
  60   // BrowserContextKeyedBaseFactories that return true from
  61   // ServiceIsNULLWhileTesting().
  62   void CreateBrowserContextServicesForTest(content::BrowserContext* context);
  63
  64   // Called by each BrowserContext to alert us that we should destroy services
  65   // associated with it.
  66   void DestroyBrowserContextServices(content::BrowserContext* context);
  67
  68   // Registers a |callback| that will be called just before executing
  69   // CreateBrowserContextServices() or CreateBrowserContextServicesForTest().
  70   // This can be useful in browser tests which wish to substitute test or mock
  71   // builders for the keyed services.
  72   scoped_ptr<base::CallbackList<void(content::BrowserContext*)>::Subscription>
  73   RegisterWillCreateBrowserContextServicesCallbackForTesting(
  74       const base::Callback<void(content::BrowserContext*)>& callback);
  75
  76 #ifndef NDEBUG
  77   // Debugging assertion called as part of GetServiceForBrowserContext in debug
  78   // mode. This will NOTREACHED() whenever the user is trying to access a stale
  79   // BrowserContext*.
  80   void AssertBrowserContextWasntDestroyed(content::BrowserContext* context);
  81
  82   // Marks |context| as live (i.e., not stale). This method can be called as a
  83   // safeguard against |AssertBrowserContextWasntDestroyed()| checks going off
  84   // due to |context| aliasing a BrowserContext instance from a prior test
  85   // (i.e., 0xWhatever might be created, be destroyed, and then a new
  86   // BrowserContext object might be created at 0xWhatever).
  87   void MarkBrowserContextLiveForTesting(content::BrowserContext* context);
  88 #endif
  89
  90   static BrowserContextDependencyManager* GetInstance();
  91
  92  private:
  93   friend class BrowserContextDependencyManagerUnittests;
  94   friend struct DefaultSingletonTraits<BrowserContextDependencyManager>;
  95
  96   // Helper function used by CreateBrowserContextServices[ForTest].
  97   void DoCreateBrowserContextServices(content::BrowserContext* context,
  98                                       bool is_testing_context);
  99
 100   BrowserContextDependencyManager();
 101   virtual ~BrowserContextDependencyManager();
 102
 103 #ifndef NDEBUG
 104   void DumpBrowserContextDependencies(content::BrowserContext* context);
 105 #endif
 106
 107   DependencyGraph dependency_graph_;
 108
 109   // A list of callbacks to call just before executing
 110   // CreateBrowserContextServices() or CreateBrowserContextServicesForTest().
 111   base::CallbackList<void(content::BrowserContext*)>
 112       will_create_browser_context_services_callbacks_;
 113
 114 #ifndef NDEBUG
 115   // A list of context objects that have gone through the Shutdown()
 116   // phase. These pointers are most likely invalid, but we keep track of their
 117   // locations in memory so we can nicely assert if we're asked to do anything
 118   // with them.
 119   std::set<content::BrowserContext*> dead_context_pointers_;
 120 #endif
 121 };
 122
 123 #endif  // COMPONENTS_KEYED_SERVICE_CONTENT_BROWSER_CONTEXT_DEPENDENCY_MANAGER_H_