1 files changed, 81 insertions, 0 deletions
diff --git a/dom/fetch/FetchObserver.cpp b/dom/fetch/FetchObserver.cpp
new file mode 100644
index 0000000000..7bdf6b2db8
--- /dev/null
+++ b/dom/fetch/FetchObserver.cpp
@@ -0,0 +1,81 @@
+/* -*- 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 "FetchObserver.h"
+#include "mozilla/dom/Event.h"
+#include "mozilla/dom/EventBinding.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(FetchObserver)
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(FetchObserver,
+                                                  DOMEventTargetHelper)
+  AbortFollower::Traverse(static_cast<AbortFollower*>(tmp), cb);
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(FetchObserver,
+                                                DOMEventTargetHelper)
+  AbortFollower::Unlink(static_cast<AbortFollower*>(tmp));
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(FetchObserver)
+NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
+
+NS_IMPL_ADDREF_INHERITED(FetchObserver, DOMEventTargetHelper)
+NS_IMPL_RELEASE_INHERITED(FetchObserver, DOMEventTargetHelper)
+
+FetchObserver::FetchObserver(nsIGlobalObject* aGlobal,
+                             AbortSignalImpl* aSignalImpl)
+    : DOMEventTargetHelper(aGlobal), mState(FetchState::Requesting) {
+  if (aSignalImpl) {
+    Follow(aSignalImpl);
+  }
+}
+
+JSObject* FetchObserver::WrapObject(JSContext* aCx,
+                                    JS::Handle<JSObject*> aGivenProto) {
+  return FetchObserver_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+FetchState FetchObserver::State() const { return mState; }
+
+void FetchObserver::RunAbortAlgorithm() { SetState(FetchState::Aborted); }
+
+void FetchObserver::SetState(FetchState aState) {
+  MOZ_ASSERT(mState < aState);
+
+  if (mState == FetchState::Aborted || mState == FetchState::Errored ||
+      mState == FetchState::Complete) {
+    // We are already in a final state.
+    return;
+  }
+
+  // We cannot pass from Requesting to Complete directly.
+  if (mState == FetchState::Requesting && aState == FetchState::Complete) {
+    SetState(FetchState::Responding);
+  }
+
+  mState = aState;
+
+  if (mState == FetchState::Aborted || mState == FetchState::Errored ||
+      mState == FetchState::Complete) {
+    Unfollow();
+  }
+
+  EventInit init;
+  init.mBubbles = false;
+  init.mCancelable = false;
+
+  // TODO which kind of event should we dispatch here?
+
+  RefPtr<Event> event = Event::Constructor(this, u"statechange"_ns, init);
+  event->SetTrusted(true);
+
+  DispatchEvent(*event);
+}
+
+}  // namespace mozilla::dom