dom/streams/TransformStream.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef DOM_STREAMS_TRANSFORMSTREAM_H_
   8 #define DOM_STREAMS_TRANSFORMSTREAM_H_
   9
  10 #include "TransformStreamDefaultController.h"
  11 #include "mozilla/dom/BindingDeclarations.h"
  12 #include "mozilla/dom/QueuingStrategyBinding.h"
  13
  14 #include "mozilla/dom/TransformerBinding.h"
  15 #include "nsCycleCollectionParticipant.h"
  16 #include "nsWrapperCache.h"
  17
  18 namespace mozilla::dom {
  19
  20 class WritableStream;
  21 class ReadableStream;
  22
  23 class TransformStream final : public nsISupports, public nsWrapperCache {
  24  public:
  25   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  26   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(TransformStream)
  27
  28   // Internal slot accessors
  29   bool Backpressure() const { return mBackpressure; }
  30   void SetBackpressure(bool aBackpressure) { mBackpressure = aBackpressure; }
  31   Promise* BackpressureChangePromise() { return mBackpressureChangePromise; }
  32   void SetBackpressureChangePromise(Promise* aPromise) {
  33     mBackpressureChangePromise = aPromise;
  34   }
  35   MOZ_KNOWN_LIVE TransformStreamDefaultController* Controller() {
  36     return mController;
  37   }
  38   void SetController(TransformStreamDefaultController& aController) {
  39     MOZ_ASSERT(!mController);
  40     mController = &aController;
  41   }
  42   MOZ_KNOWN_LIVE ReadableStream* Readable() { return mReadable; }
  43   MOZ_KNOWN_LIVE WritableStream* Writable() { return mWritable; }
  44
  45  protected:
  46   ~TransformStream();
  47   explicit TransformStream(nsIGlobalObject* aGlobal);
  48
  49   MOZ_CAN_RUN_SCRIPT void Initialize(
  50       JSContext* aCx, Promise* aStartPromise, double aWritableHighWaterMark,
  51       QueuingStrategySize* aWritableSizeAlgorithm,
  52       double aReadableHighWaterMark,
  53       QueuingStrategySize* aReadableSizeAlgorithm, ErrorResult& aRv);
  54
  55  public:
  56   nsIGlobalObject* GetParentObject() const { return mGlobal; }
  57   JSObject* WrapObject(JSContext* aCx,
  58                        JS::Handle<JSObject*> aGivenProto) override;
  59
  60   // WebIDL methods
  61   // TODO: Mark as MOZ_CAN_RUN_SCRIPT when IDL constructors can be (bug 1749042)
  62   MOZ_CAN_RUN_SCRIPT_BOUNDARY static already_AddRefed<TransformStream>
  63   Constructor(const GlobalObject& aGlobal,
  64               const Optional<JS::Handle<JSObject*>>& aTransformer,
  65               const QueuingStrategy& aWritableStrategy,
  66               const QueuingStrategy& aReadableStrategy, ErrorResult& aRv);
  67
  68   already_AddRefed<ReadableStream> GetReadable();
  69   already_AddRefed<WritableStream> GetWritable();
  70
  71  private:
  72   nsCOMPtr<nsIGlobalObject> mGlobal;
  73
  74   // Internal slots
  75   // MOZ_KNOWN_LIVE for slots that will never be reassigned
  76   bool mBackpressure = false;
  77   RefPtr<Promise> mBackpressureChangePromise;
  78   MOZ_KNOWN_LIVE RefPtr<TransformStreamDefaultController> mController;
  79   MOZ_KNOWN_LIVE RefPtr<ReadableStream> mReadable;
  80   MOZ_KNOWN_LIVE RefPtr<WritableStream> mWritable;
  81 };
  82
  83 MOZ_CAN_RUN_SCRIPT void TransformStreamErrorWritableAndUnblockWrite(
  84     JSContext* aCx, TransformStream* aStream, JS::Handle<JS::Value> aError,
  85     ErrorResult& aRv);
  86
  87 MOZ_CAN_RUN_SCRIPT void TransformStreamError(JSContext* aCx,
  88                                              TransformStream* aStream,
  89                                              JS::Handle<JS::Value> aError,
  90                                              ErrorResult& aRv);
  91
  92 void TransformStreamSetBackpressure(TransformStream* aStream,
  93                                     bool aBackpressure, ErrorResult& aRv);
  94
  95 }  // namespace mozilla::dom
  96
  97 #endif  // DOM_STREAMS_TRANSFORMSTREAM_H_