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 class UniqueMessagePortId;
  23 class MessagePort;
  24 class TransformerAlgorithmsWrapper;
  25
  26 class TransformStream final : public nsISupports, public nsWrapperCache {
  27  public:
  28   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  29   NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(TransformStream)
  30
  31   // https://streams.spec.whatwg.org/#transformstream-set-up
  32   // Intended to be used by interfaces using GenericTransformStream mixin.
  33   MOZ_CAN_RUN_SCRIPT static already_AddRefed<TransformStream> CreateGeneric(
  34       const GlobalObject& aGlobal, TransformerAlgorithmsWrapper& aAlgorithms,
  35       ErrorResult& aRv);
  36
  37   // Internal slot accessors
  38   bool Backpressure() const { return mBackpressure; }
  39   Promise* BackpressureChangePromise() { return mBackpressureChangePromise; }
  40   void SetBackpressure(bool aBackpressure);
  41   MOZ_KNOWN_LIVE TransformStreamDefaultController* Controller() {
  42     return mController;
  43   }
  44   void SetController(TransformStreamDefaultController& aController) {
  45     MOZ_ASSERT(!mController);
  46     mController = &aController;
  47   }
  48
  49   // [Transferable]
  50   // https://html.spec.whatwg.org/multipage/structured-data.html#transfer-steps
  51   MOZ_CAN_RUN_SCRIPT bool Transfer(JSContext* aCx,
  52                                    UniqueMessagePortId& aPortId1,
  53                                    UniqueMessagePortId& aPortId2);
  54   // https://html.spec.whatwg.org/multipage/structured-data.html#transfer-receiving-steps
  55   static MOZ_CAN_RUN_SCRIPT bool ReceiveTransfer(
  56       JSContext* aCx, nsIGlobalObject* aGlobal, MessagePort& aPort1,
  57       MessagePort& aPort2, JS::MutableHandle<JSObject*> aReturnObject);
  58
  59  protected:
  60   TransformStream(nsIGlobalObject* aGlobal, ReadableStream* aReadable,
  61                   WritableStream* aWritable);
  62   explicit TransformStream(nsIGlobalObject* aGlobal);
  63
  64   ~TransformStream();
  65
  66   MOZ_CAN_RUN_SCRIPT void Initialize(
  67       JSContext* aCx, Promise* aStartPromise, double aWritableHighWaterMark,
  68       QueuingStrategySize* aWritableSizeAlgorithm,
  69       double aReadableHighWaterMark,
  70       QueuingStrategySize* aReadableSizeAlgorithm, ErrorResult& aRv);
  71
  72  public:
  73   nsIGlobalObject* GetParentObject() const { return mGlobal; }
  74   JSObject* WrapObject(JSContext* aCx,
  75                        JS::Handle<JSObject*> aGivenProto) override;
  76
  77   // WebIDL methods
  78   // TODO: Mark as MOZ_CAN_RUN_SCRIPT when IDL constructors can be (bug 1749042)
  79   MOZ_CAN_RUN_SCRIPT_BOUNDARY static already_AddRefed<TransformStream>
  80   Constructor(const GlobalObject& aGlobal,
  81               const Optional<JS::Handle<JSObject*>>& aTransformer,
  82               const QueuingStrategy& aWritableStrategy,
  83               const QueuingStrategy& aReadableStrategy, ErrorResult& aRv);
  84
  85   ReadableStream* Readable() const { return mReadable; }
  86   WritableStream* Writable() const { return mWritable; }
  87
  88  private:
  89   nsCOMPtr<nsIGlobalObject> mGlobal;
  90
  91   // Internal slots
  92   // MOZ_KNOWN_LIVE for slots that will never be reassigned
  93   bool mBackpressure = false;
  94   RefPtr<Promise> mBackpressureChangePromise;
  95   RefPtr<TransformStreamDefaultController> mController;
  96   RefPtr<ReadableStream> mReadable;
  97   RefPtr<WritableStream> mWritable;
  98 };
  99
 100 namespace streams_abstract {
 101
 102 MOZ_CAN_RUN_SCRIPT void TransformStreamErrorWritableAndUnblockWrite(
 103     JSContext* aCx, TransformStream* aStream, JS::Handle<JS::Value> aError,
 104     ErrorResult& aRv);
 105
 106 MOZ_CAN_RUN_SCRIPT void TransformStreamError(JSContext* aCx,
 107                                              TransformStream* aStream,
 108                                              JS::Handle<JS::Value> aError,
 109                                              ErrorResult& aRv);
 110
 111 }  // namespace streams_abstract
 112
 113 }  // namespace mozilla::dom
 114
 115 #endif  // DOM_STREAMS_TRANSFORMSTREAM_H_