1 files changed, 161 insertions, 0 deletions
diff --git a/dom/ipc/RefMessageBodyService.cpp b/dom/ipc/RefMessageBodyService.cpp
new file mode 100644
index 0000000000..e340443a53
--- /dev/null
+++ b/dom/ipc/RefMessageBodyService.cpp
@@ -0,0 +1,161 @@
+/* -*- 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 "RefMessageBodyService.h"
+
+#include <cstdint>
+#include <cstdlib>
+#include "mozilla/ErrorResult.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/dom/ipc/StructuredCloneData.h"
+#include "nsBaseHashtable.h"
+#include "nsDebug.h"
+
+namespace mozilla::dom {
+
+// Guards sService and its members.
+StaticMutex sRefMessageBodyServiceMutex;
+
+// Raw pointer because the service is kept alive by other objects.
+// See the CTOR and the DTOR of this object.
+RefMessageBodyService* sService;
+
+// static
+already_AddRefed<RefMessageBodyService> RefMessageBodyService::GetOrCreate() {
+  StaticMutexAutoLock lock(sRefMessageBodyServiceMutex);
+
+  RefPtr<RefMessageBodyService> service = GetOrCreateInternal(lock);
+  return service.forget();
+}
+
+// static
+RefMessageBodyService* RefMessageBodyService::GetOrCreateInternal(
+    const StaticMutexAutoLock& aProofOfLock) {
+  if (!sService) {
+    sService = new RefMessageBodyService(aProofOfLock);
+  }
+  return sService;
+}
+
+RefMessageBodyService::RefMessageBodyService(
+    const StaticMutexAutoLock& aProofOfLock) {
+  MOZ_DIAGNOSTIC_ASSERT(sService == nullptr);
+}
+
+RefMessageBodyService::~RefMessageBodyService() {
+  StaticMutexAutoLock lock(sRefMessageBodyServiceMutex);
+  MOZ_DIAGNOSTIC_ASSERT(sService == this);
+  sService = nullptr;
+}
+
+const nsID RefMessageBodyService::Register(
+    already_AddRefed<RefMessageBody> aBody, ErrorResult& aRv) {
+  RefPtr<RefMessageBody> body = aBody;
+  MOZ_ASSERT(body);
+
+  nsID uuid = {};
+  aRv = nsID::GenerateUUIDInPlace(uuid);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nsID();
+  }
+
+  StaticMutexAutoLock lock(sRefMessageBodyServiceMutex);
+  GetOrCreateInternal(lock)->mMessages.InsertOrUpdate(uuid, std::move(body));
+  return uuid;
+}
+
+already_AddRefed<RefMessageBody> RefMessageBodyService::Steal(const nsID& aID) {
+  StaticMutexAutoLock lock(sRefMessageBodyServiceMutex);
+  if (!sService) {
+    return nullptr;
+  }
+
+  RefPtr<RefMessageBody> body;
+  sService->mMessages.Remove(aID, getter_AddRefs(body));
+
+  return body.forget();
+}
+
+already_AddRefed<RefMessageBody> RefMessageBodyService::GetAndCount(
+    const nsID& aID) {
+  StaticMutexAutoLock lock(sRefMessageBodyServiceMutex);
+  if (!sService) {
+    return nullptr;
+  }
+
+  RefPtr<RefMessageBody> body = sService->mMessages.Get(aID);
+  if (!body) {
+    return nullptr;
+  }
+
+  ++body->mCount;
+
+  MOZ_ASSERT_IF(body->mMaxCount.isSome(),
+                body->mCount <= body->mMaxCount.value());
+  if (body->mMaxCount.isSome() && body->mCount >= body->mMaxCount.value()) {
+    sService->mMessages.Remove(aID);
+  }
+
+  return body.forget();
+}
+
+void RefMessageBodyService::SetMaxCount(const nsID& aID, uint32_t aMaxCount) {
+  StaticMutexAutoLock lock(sRefMessageBodyServiceMutex);
+  if (!sService) {
+    return;
+  }
+
+  RefPtr<RefMessageBody> body = sService->mMessages.Get(aID);
+  if (!body) {
+    return;
+  }
+
+  MOZ_ASSERT(body->mMaxCount.isNothing());
+  body->mMaxCount.emplace(aMaxCount);
+
+  MOZ_ASSERT(body->mCount <= body->mMaxCount.value());
+  if (body->mCount >= body->mMaxCount.value()) {
+    sService->mMessages.Remove(aID);
+  }
+}
+
+void RefMessageBodyService::ForgetPort(const nsID& aPortID) {
+  StaticMutexAutoLock lock(sRefMessageBodyServiceMutex);
+  if (!sService) {
+    return;
+  }
+
+  for (auto iter = sService->mMessages.Iter(); !iter.Done(); iter.Next()) {
+    if (iter.UserData()->PortID() == aPortID) {
+      iter.Remove();
+    }
+  }
+}
+
+RefMessageBody::RefMessageBody(const nsID& aPortID,
+                               UniquePtr<ipc::StructuredCloneData>&& aCloneData)
+    : mPortID(aPortID),
+      mMutex("RefMessageBody::mMutex"),
+      mCloneData(std::move(aCloneData)),
+      mMaxCount(Nothing()),
+      mCount(0) {}
+
+RefMessageBody::~RefMessageBody() = default;
+
+void RefMessageBody::Read(JSContext* aCx, JS::MutableHandle<JS::Value> aValue,
+                          const JS::CloneDataPolicy& aCloneDataPolicy,
+                          ErrorResult& aRv) {
+  MutexAutoLock lock(mMutex);
+  mCloneData->Read(aCx, aValue, aCloneDataPolicy, aRv);
+}
+
+bool RefMessageBody::TakeTransferredPortsAsSequence(
+    Sequence<OwningNonNull<mozilla::dom::MessagePort>>& aPorts) {
+  MOZ_ASSERT(mMaxCount.isNothing());
+  return mCloneData->TakeTransferredPortsAsSequence(aPorts);
+}
+
+}  // namespace mozilla::dom