/* 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_cache_StreamControl_h
#define mozilla_dom_cache_StreamControl_h

#include "mozilla/dom/cache/ReadStream.h"
#include "mozilla/dom/cache/Types.h"
#include "nsTObserverArray.h"

struct nsID;

namespace mozilla::dom::cache {

class CacheReadStream;

// Abstract class to help implement the stream control Child and Parent actors.
// This provides an interface to partly help with serialization of IPC types,
// but also an implementation for tracking ReadStream objects.
class StreamControl {
 public:
  // abstract interface that must be implemented by child class
  virtual void SerializeControl(CacheReadStream* aReadStreamOut) = 0;

  virtual void SerializeStream(CacheReadStream* aReadStreamOut,
                               nsIInputStream* aStream) = 0;

  virtual void OpenStream(const nsID& aId, InputStreamResolver&& aResolver) = 0;

  // inherited implementation of the ReadStream::Controllable list

  // Begin controlling the given ReadStream.  This causes a strong ref to
  // be held by the control.  The ReadStream must call NoteClosed() or
  // ForgetReadStream() to release this ref.
  void AddReadStream(SafeRefPtr<ReadStream::Controllable> aReadStream);

  // Forget the ReadStream without notifying the actor.
  void ForgetReadStream(SafeRefPtr<ReadStream::Controllable> aReadStream);

  // Forget the ReadStream and then notify the actor the stream is closed.
  void NoteClosed(SafeRefPtr<ReadStream::Controllable> aReadStream,
                  const nsID& aId);

 protected:
  ~StreamControl();

  void CloseAllReadStreams();

  void CloseAllReadStreamsWithoutReporting();

  bool HasEverBeenRead() const;

  // protected parts of the abstract interface
  virtual void NoteClosedAfterForget(const nsID& aId) = 0;

#ifdef DEBUG
  virtual void AssertOwningThread() = 0;
#else
  void AssertOwningThread() {}
#endif

 private:
  // Hold strong references to ReadStream object.  When the stream is closed
  // it should call NoteClosed() or ForgetReadStream() to release this ref.
  using ReadStreamList = nsTObserverArray<SafeRefPtr<ReadStream::Controllable>>;
  ReadStreamList mReadStreamList;
};

}  // namespace mozilla::dom::cache

#endif  // mozilla_dom_cache_StreamControl_h