AbortSignal.h - mozsearch

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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/RefPtr.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);

  static already_AddRefed<AbortSignal> Any(

      GlobalObject& aGlobal,

      const Sequence<OwningNonNull<AbortSignal>>& aSignals);

  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; }

  bool Dependent() const;

 protected:

  ~AbortSignal();

  void MakeDependentOn(AbortSignal* aSignal);

  nsTArray<WeakPtr<AbortSignal>> mSourceSignals;

  nsTArray<RefPtr<AbortSignal>> mDependentSignals;

  bool mDependent;

};

}  // namespace mozilla::dom

#endif  // mozilla_dom_AbortSignal_h