dom/storage/StorageNotifierService.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "StorageNotifierService.h"
   8 #include "mozilla/ClearOnShutdown.h"
   9 #include "mozilla/StaticPtr.h"
  10
  11 namespace mozilla {
  12 namespace dom {
  13
  14 namespace {
  15
  16 // This boolean is used to avoid the creation of the service after been
  17 // distroyed on shutdown.
  18 bool gStorageShuttingDown = false;
  19
  20 StaticRefPtr<StorageNotifierService> gStorageNotifierService;
  21
  22 }  // namespace
  23
  24 /* static */
  25 StorageNotifierService* StorageNotifierService::GetOrCreate() {
  26   MOZ_ASSERT(NS_IsMainThread());
  27   if (!gStorageNotifierService && !gStorageShuttingDown) {
  28     gStorageNotifierService = new StorageNotifierService();
  29     ClearOnShutdown(&gStorageNotifierService);
  30   }
  31
  32   return gStorageNotifierService;
  33 }
  34
  35 StorageNotifierService::StorageNotifierService() {
  36   MOZ_ASSERT(NS_IsMainThread());
  37   MOZ_ASSERT(!gStorageNotifierService);
  38 }
  39
  40 StorageNotifierService::~StorageNotifierService() {
  41   MOZ_ASSERT(NS_IsMainThread());
  42   MOZ_ASSERT(!gStorageNotifierService);
  43   gStorageShuttingDown = true;
  44 }
  45
  46 /* static */
  47 void StorageNotifierService::Broadcast(StorageEvent* aEvent,
  48                                        const char16_t* aStorageType,
  49                                        bool aPrivateBrowsing,
  50                                        bool aImmediateDispatch) {
  51   MOZ_ASSERT(NS_IsMainThread());
  52
  53   RefPtr<StorageNotifierService> service = gStorageNotifierService;
  54   if (!service) {
  55     return;
  56   }
  57
  58   RefPtr<StorageEvent> event = aEvent;
  59
  60   nsTObserverArray<RefPtr<StorageNotificationObserver>>::ForwardIterator iter(
  61       service->mObservers);
  62
  63   while (iter.HasMore()) {
  64     RefPtr<StorageNotificationObserver> observer = iter.GetNext();
  65
  66     // Enforce that the source storage area's private browsing state matches
  67     // this window's state.  These flag checks and their maintenance independent
  68     // from the principal's OriginAttributes matter because chrome docshells
  69     // that are part of private browsing windows can be private browsing without
  70     // having their OriginAttributes set (because they have the system
  71     // principal).
  72     if (aPrivateBrowsing != observer->IsPrivateBrowsing()) {
  73       continue;
  74     }
  75
  76     // No reasons to continue if the principal of the event doesn't match with
  77     // the window's one.
  78     if (!StorageUtils::PrincipalsEqual(
  79             aEvent->GetPrincipal(), observer->GetEffectiveStoragePrincipal())) {
  80       continue;
  81     }
  82
  83     RefPtr<Runnable> r = NS_NewRunnableFunction(
  84         "StorageNotifierService::Broadcast",
  85         [observer, event, aStorageType, aPrivateBrowsing]() {
  86           observer->ObserveStorageNotification(event, aStorageType,
  87                                                aPrivateBrowsing);
  88         });
  89
  90     if (aImmediateDispatch) {
  91       r->Run();
  92     } else {
  93       nsCOMPtr<nsIEventTarget> et = observer->GetEventTarget();
  94       if (et) {
  95         et->Dispatch(r.forget());
  96       }
  97     }
  98   }
  99 }
 100
 101 void StorageNotifierService::Register(StorageNotificationObserver* aObserver) {
 102   MOZ_ASSERT(NS_IsMainThread());
 103   MOZ_ASSERT(aObserver);
 104   MOZ_ASSERT(!mObservers.Contains(aObserver));
 105
 106   mObservers.AppendElement(aObserver);
 107 }
 108
 109 void StorageNotifierService::Unregister(
 110     StorageNotificationObserver* aObserver) {
 111   MOZ_ASSERT(NS_IsMainThread());
 112   MOZ_ASSERT(aObserver);
 113
 114   // No assertion about mObservers containing aObserver because window calls
 115   // this method multiple times.
 116
 117   mObservers.RemoveElement(aObserver);
 118 }
 119
 120 }  // namespace dom
 121 }  // namespace mozilla