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