dom/broadcastchannel/BroadcastChannelService.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 "BroadcastChannelService.h"
   8 #include "BroadcastChannelParent.h"
   9 #include "mozilla/dom/BlobImpl.h"
  10 #include "mozilla/dom/File.h"
  11 #include "mozilla/dom/IPCBlobUtils.h"
  12 #include "mozilla/ipc/BackgroundParent.h"
  13
  14 #ifdef XP_WIN
  15 #  undef PostMessage
  16 #endif
  17
  18 namespace mozilla {
  19
  20 using namespace ipc;
  21
  22 namespace dom {
  23
  24 namespace {
  25
  26 BroadcastChannelService* sInstance = nullptr;
  27
  28 ClonedMessageData CloneClonedMessageData(const ClonedMessageData& aOther) {
  29   auto cloneData = SerializedStructuredCloneBuffer{};
  30   cloneData.data.initScope(aOther.data().data.scope());
  31   const bool res = cloneData.data.Append(aOther.data().data);
  32   MOZ_RELEASE_ASSERT(res, "out of memory");
  33   return {std::move(cloneData), aOther.blobs(), aOther.inputStreams(),
  34           aOther.identifiers()};
  35 }
  36
  37 MessageData CloneMessageData(const MessageData& aOther) {
  38   switch (aOther.data().type()) {
  39     case MessageDataType::TClonedMessageData:
  40       return {aOther.agentClusterId(),
  41               CloneClonedMessageData(aOther.data().get_ClonedMessageData())};
  42     case MessageDataType::TRefMessageData:
  43       return {aOther.agentClusterId(), aOther.data().get_RefMessageData()};
  44     default:
  45       MOZ_CRASH("Unexpected MessageDataType type");
  46   }
  47 }
  48
  49 }  // namespace
  50
  51 BroadcastChannelService::BroadcastChannelService() {
  52   AssertIsOnBackgroundThread();
  53
  54   // sInstance is a raw BroadcastChannelService*.
  55   MOZ_ASSERT(!sInstance);
  56   sInstance = this;
  57 }
  58
  59 BroadcastChannelService::~BroadcastChannelService() {
  60   AssertIsOnBackgroundThread();
  61   MOZ_ASSERT(sInstance == this);
  62   MOZ_ASSERT(mAgents.Count() == 0);
  63
  64   sInstance = nullptr;
  65 }
  66
  67 // static
  68 already_AddRefed<BroadcastChannelService>
  69 BroadcastChannelService::GetOrCreate() {
  70   AssertIsOnBackgroundThread();
  71
  72   RefPtr<BroadcastChannelService> instance = sInstance;
  73   if (!instance) {
  74     instance = new BroadcastChannelService();
  75   }
  76   return instance.forget();
  77 }
  78
  79 void BroadcastChannelService::RegisterActor(
  80     BroadcastChannelParent* aParent, const nsAString& aOriginChannelKey) {
  81   AssertIsOnBackgroundThread();
  82   MOZ_ASSERT(aParent);
  83
  84   auto* const parents = mAgents.GetOrInsertNew(aOriginChannelKey);
  85
  86   MOZ_ASSERT(!parents->Contains(aParent));
  87   parents->AppendElement(aParent);
  88 }
  89
  90 void BroadcastChannelService::UnregisterActor(
  91     BroadcastChannelParent* aParent, const nsAString& aOriginChannelKey) {
  92   AssertIsOnBackgroundThread();
  93   MOZ_ASSERT(aParent);
  94
  95   if (auto entry = mAgents.Lookup(aOriginChannelKey)) {
  96     entry.Data()->RemoveElement(aParent);
  97     // remove the entry if the array is now empty
  98     if (entry.Data()->IsEmpty()) {
  99       entry.Remove();
 100     }
 101   } else {
 102     MOZ_CRASH("Invalid state");
 103   }
 104 }
 105
 106 void BroadcastChannelService::PostMessage(BroadcastChannelParent* aParent,
 107                                           const MessageData& aData,
 108                                           const nsAString& aOriginChannelKey) {
 109   AssertIsOnBackgroundThread();
 110   MOZ_ASSERT(aParent);
 111
 112   nsTArray<BroadcastChannelParent*>* parents;
 113   if (!mAgents.Get(aOriginChannelKey, &parents)) {
 114     MOZ_CRASH("Invalid state");
 115   }
 116
 117   // We need to keep the array alive for the life-time of this operation.
 118   nsTArray<RefPtr<BlobImpl>> blobImpls;
 119   if (aData.data().type() == MessageDataType::TClonedMessageData) {
 120     const nsTArray<IPCBlob>& blobs =
 121         aData.data().get_ClonedMessageData().blobs();
 122     if (!blobs.IsEmpty()) {
 123       blobImpls.SetCapacity(blobs.Length());
 124
 125       for (uint32_t i = 0, len = blobs.Length(); i < len; ++i) {
 126         RefPtr<BlobImpl> impl = IPCBlobUtils::Deserialize(blobs[i]);
 127
 128         MOZ_ASSERT(impl);
 129         blobImpls.AppendElement(impl);
 130       }
 131     }
 132   }
 133
 134   uint32_t selectedActorsOnSamePid = 0;
 135
 136   // For each parent actor, we notify the message.
 137   for (uint32_t i = 0; i < parents->Length(); ++i) {
 138     BroadcastChannelParent* parent = parents->ElementAt(i);
 139     MOZ_ASSERT(parent);
 140
 141     if (parent == aParent) {
 142       continue;
 143     }
 144
 145     if (parent->OtherPid() == aParent->OtherPid()) {
 146       ++selectedActorsOnSamePid;
 147     }
 148
 149     // We need to have a copy of the data for this parent.
 150     MessageData newData = CloneMessageData(aData);
 151     MOZ_ASSERT(newData.data().type() == aData.data().type());
 152
 153     if (!blobImpls.IsEmpty()) {
 154       nsTArray<IPCBlob>& newBlobImpls =
 155           newData.data().get_ClonedMessageData().blobs();
 156       MOZ_ASSERT(blobImpls.Length() == newBlobImpls.Length());
 157
 158       // Serialize Blob objects for this message.
 159       for (uint32_t i = 0, len = blobImpls.Length(); i < len; ++i) {
 160         nsresult rv = IPCBlobUtils::Serialize(blobImpls[i], newBlobImpls[i]);
 161         if (NS_WARN_IF(NS_FAILED(rv))) {
 162           return;
 163         }
 164       }
 165     }
 166
 167     Unused << parent->SendNotify(newData);
 168   }
 169
 170   // If this is a refMessageData, we need to know when it can be released.
 171   if (aData.data().type() == MessageDataType::TRefMessageData) {
 172     Unused << aParent->SendRefMessageDelivered(
 173         aData.data().get_RefMessageData().uuid(), selectedActorsOnSamePid);
 174   }
 175 }
 176
 177 }  // namespace dom
 178 }  // namespace mozilla