1 files changed, 178 insertions, 0 deletions
diff --git a/dom/broadcastchannel/BroadcastChannelService.cpp b/dom/broadcastchannel/BroadcastChannelService.cpp
new file mode 100644
index 0000000000..c3dab2b28a
--- /dev/null
+++ b/dom/broadcastchannel/BroadcastChannelService.cpp
@@ -0,0 +1,178 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "BroadcastChannelService.h"
+#include "BroadcastChannelParent.h"
+#include "mozilla/dom/BlobImpl.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/IPCBlobUtils.h"
+#include "mozilla/ipc/BackgroundParent.h"
+
+#ifdef XP_WIN
+#  undef PostMessage
+#endif
+
+namespace mozilla {
+
+using namespace ipc;
+
+namespace dom {
+
+namespace {
+
+BroadcastChannelService* sInstance = nullptr;
+
+ClonedMessageData CloneClonedMessageData(const ClonedMessageData& aOther) {
+  auto cloneData = SerializedStructuredCloneBuffer{};
+  cloneData.data.initScope(aOther.data().data.scope());
+  const bool res = cloneData.data.Append(aOther.data().data);
+  MOZ_RELEASE_ASSERT(res, "out of memory");
+  return {std::move(cloneData), aOther.blobs(), aOther.inputStreams(),
+          aOther.identifiers()};
+}
+
+MessageData CloneMessageData(const MessageData& aOther) {
+  switch (aOther.data().type()) {
+    case MessageDataType::TClonedMessageData:
+      return {aOther.agentClusterId(),
+              CloneClonedMessageData(aOther.data().get_ClonedMessageData())};
+    case MessageDataType::TRefMessageData:
+      return {aOther.agentClusterId(), aOther.data().get_RefMessageData()};
+    default:
+      MOZ_CRASH("Unexpected MessageDataType type");
+  }
+}
+
+}  // namespace
+
+BroadcastChannelService::BroadcastChannelService() {
+  AssertIsOnBackgroundThread();
+
+  // sInstance is a raw BroadcastChannelService*.
+  MOZ_ASSERT(!sInstance);
+  sInstance = this;
+}
+
+BroadcastChannelService::~BroadcastChannelService() {
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(sInstance == this);
+  MOZ_ASSERT(mAgents.Count() == 0);
+
+  sInstance = nullptr;
+}
+
+// static
+already_AddRefed<BroadcastChannelService>
+BroadcastChannelService::GetOrCreate() {
+  AssertIsOnBackgroundThread();
+
+  RefPtr<BroadcastChannelService> instance = sInstance;
+  if (!instance) {
+    instance = new BroadcastChannelService();
+  }
+  return instance.forget();
+}
+
+void BroadcastChannelService::RegisterActor(
+    BroadcastChannelParent* aParent, const nsAString& aOriginChannelKey) {
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aParent);
+
+  auto* const parents = mAgents.GetOrInsertNew(aOriginChannelKey);
+
+  MOZ_ASSERT(!parents->Contains(aParent));
+  parents->AppendElement(aParent);
+}
+
+void BroadcastChannelService::UnregisterActor(
+    BroadcastChannelParent* aParent, const nsAString& aOriginChannelKey) {
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aParent);
+
+  if (auto entry = mAgents.Lookup(aOriginChannelKey)) {
+    entry.Data()->RemoveElement(aParent);
+    // remove the entry if the array is now empty
+    if (entry.Data()->IsEmpty()) {
+      entry.Remove();
+    }
+  } else {
+    MOZ_CRASH("Invalid state");
+  }
+}
+
+void BroadcastChannelService::PostMessage(BroadcastChannelParent* aParent,
+                                          const MessageData& aData,
+                                          const nsAString& aOriginChannelKey) {
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aParent);
+
+  nsTArray<BroadcastChannelParent*>* parents;
+  if (!mAgents.Get(aOriginChannelKey, &parents)) {
+    MOZ_CRASH("Invalid state");
+  }
+
+  // We need to keep the array alive for the life-time of this operation.
+  nsTArray<RefPtr<BlobImpl>> blobImpls;
+  if (aData.data().type() == MessageDataType::TClonedMessageData) {
+    const nsTArray<IPCBlob>& blobs =
+        aData.data().get_ClonedMessageData().blobs();
+    if (!blobs.IsEmpty()) {
+      blobImpls.SetCapacity(blobs.Length());
+
+      for (uint32_t i = 0, len = blobs.Length(); i < len; ++i) {
+        RefPtr<BlobImpl> impl = IPCBlobUtils::Deserialize(blobs[i]);
+
+        MOZ_ASSERT(impl);
+        blobImpls.AppendElement(impl);
+      }
+    }
+  }
+
+  uint32_t selectedActorsOnSamePid = 0;
+
+  // For each parent actor, we notify the message.
+  for (uint32_t i = 0; i < parents->Length(); ++i) {
+    BroadcastChannelParent* parent = parents->ElementAt(i);
+    MOZ_ASSERT(parent);
+
+    if (parent == aParent) {
+      continue;
+    }
+
+    if (parent->OtherPid() == aParent->OtherPid()) {
+      ++selectedActorsOnSamePid;
+    }
+
+    // We need to have a copy of the data for this parent.
+    MessageData newData = CloneMessageData(aData);
+    MOZ_ASSERT(newData.data().type() == aData.data().type());
+
+    if (!blobImpls.IsEmpty()) {
+      nsTArray<IPCBlob>& newBlobImpls =
+          newData.data().get_ClonedMessageData().blobs();
+      MOZ_ASSERT(blobImpls.Length() == newBlobImpls.Length());
+
+      // Serialize Blob objects for this message.
+      for (uint32_t i = 0, len = blobImpls.Length(); i < len; ++i) {
+        nsresult rv = IPCBlobUtils::Serialize(blobImpls[i], newBlobImpls[i]);
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return;
+        }
+      }
+    }
+
+    Unused << parent->SendNotify(newData);
+  }
+
+  // If this is a refMessageData, we need to know when it can be released.
+  if (aData.data().type() == MessageDataType::TRefMessageData) {
+    Unused << aParent->SendRefMessageDelivered(
+        aData.data().get_RefMessageData().uuid(), selectedActorsOnSamePid);
+  }
+}
+
+}  // namespace dom
+}  // namespace mozilla