1 files changed, 66 insertions, 0 deletions
diff --git a/dom/abort/AbortSignal.h b/dom/abort/AbortSignal.h
new file mode 100644
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+++ b/dom/abort/AbortSignal.h
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+/* -*- 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/. */
+
+#ifndef mozilla_dom_AbortSignal_h
+#define mozilla_dom_AbortSignal_h
+
+#include "mozilla/dom/AbortFollower.h"
+#include "mozilla/DOMEventTargetHelper.h"
+
+namespace mozilla::dom {
+
+// AbortSignal the spec concept includes the concept of a child signal
+// "following" a parent signal -- internally, adding abort steps to the parent
+// signal that will then signal abort on the child signal -- to propagate
+// signaling abort from one signal to another.  See
+// <https://dom.spec.whatwg.org/#abortsignal-follow>.
+//
+// This requires that AbortSignal also inherit from AbortFollower.
+//
+// This ability to follow isn't directly exposed in the DOM; as of this writing
+// it appears only to be used internally in the Fetch API.  It might be a good
+// idea to split AbortSignal into an implementation that can follow, and an
+// implementation that can't, to provide this complexity only when it's needed.
+class AbortSignal : public DOMEventTargetHelper,
+                    public AbortSignalImpl,
+                    public AbortFollower {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(AbortSignal,
+                                                         DOMEventTargetHelper)
+
+  AbortSignal(nsIGlobalObject* aGlobalObject, bool aAborted,
+              JS::Handle<JS::Value> aReason);
+
+  JSObject* WrapObject(JSContext* aCx,
+                       JS::Handle<JSObject*> aGivenProto) override;
+
+  IMPL_EVENT_HANDLER(abort);
+
+  static already_AddRefed<AbortSignal> Abort(GlobalObject& aGlobal,
+                                             JS::Handle<JS::Value> aReason);
+
+  static already_AddRefed<AbortSignal> Timeout(GlobalObject& aGlobal,
+                                               uint64_t aMilliseconds,
+                                               ErrorResult& aRv);
+
+  void ThrowIfAborted(JSContext* aCx, ErrorResult& aRv);
+
+  // AbortSignalImpl
+  void SignalAbort(JS::Handle<JS::Value> aReason) override;
+
+  // AbortFollower
+  void RunAbortAlgorithm() override;
+
+  virtual bool IsTaskSignal() const { return false; }
+
+ protected:
+  ~AbortSignal();
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_AbortSignal_h