tor-browser

WritableStream.cpp (31513B)

---

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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/. */

#include "mozilla/dom/WritableStream.h"

#include "StreamUtils.h"
#include "js/Array.h"
#include "js/PropertyAndElement.h"
#include "js/TypeDecls.h"
#include "js/Value.h"
#include "mozilla/AlreadyAddRefed.h"
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/CycleCollectedJSContext.h"
#include "mozilla/HoldDropJSObjects.h"
#include "mozilla/dom/AbortSignal.h"
#include "mozilla/dom/BindingCallContext.h"
#include "mozilla/dom/Promise-inl.h"
#include "mozilla/dom/QueueWithSizes.h"
#include "mozilla/dom/QueuingStrategyBinding.h"
#include "mozilla/dom/ReadRequest.h"
#include "mozilla/dom/RootedDictionary.h"
#include "mozilla/dom/UnderlyingSinkBinding.h"
#include "mozilla/dom/WritableStreamBinding.h"
#include "mozilla/dom/WritableStreamDefaultController.h"
#include "mozilla/dom/WritableStreamDefaultWriter.h"
#include "nsCOMPtr.h"
#include "nsIGlobalObject.h"
#include "nsISupports.h"

namespace mozilla::dom {

using namespace streams_abstract;

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_WITH_JS_MEMBERS(
   WritableStream,
   (mGlobal, mCloseRequest, mController, mInFlightWriteRequest,
    mInFlightCloseRequest, mPendingAbortRequestPromise, mWriter,
    mWriteRequests),
   (mPendingAbortRequestReason, mStoredError))

NS_IMPL_CYCLE_COLLECTING_ADDREF(WritableStream)
NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE(WritableStream,
                                                  LastRelease())
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(WritableStream)
 NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
 NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

WritableStream::WritableStream(nsIGlobalObject* aGlobal,
                              HoldDropJSObjectsCaller aHoldDropCaller)
   : mGlobal(aGlobal), mHoldDropCaller(aHoldDropCaller) {
 if (mHoldDropCaller == HoldDropJSObjectsCaller::Implicit) {
   mozilla::HoldJSObjects(this);
 }
}

WritableStream::WritableStream(const GlobalObject& aGlobal,
                              HoldDropJSObjectsCaller aHoldDropCaller)
   : mGlobal(do_QueryInterface(aGlobal.GetAsSupports())),
     mHoldDropCaller(aHoldDropCaller) {
 if (mHoldDropCaller == HoldDropJSObjectsCaller::Implicit) {
   mozilla::HoldJSObjects(this);
 }
}

WritableStream::~WritableStream() {
 if (mHoldDropCaller == HoldDropJSObjectsCaller::Implicit) {
   mozilla::DropJSObjects(this);
 }
}

JSObject* WritableStream::WrapObject(JSContext* aCx,
                                    JS::Handle<JSObject*> aGivenProto) {
 return WritableStream_Binding::Wrap(aCx, this, aGivenProto);
}

// https://streams.spec.whatwg.org/#writable-stream-deal-with-rejection
void WritableStream::DealWithRejection(JSContext* aCx,
                                      JS::Handle<JS::Value> aError,
                                      ErrorResult& aRv) {
 // Step 1. Let state be stream.[[state]].
 // Step 2. If state is "writable",
 if (mState == WriterState::Writable) {
   // Step 2.1. Perform ! WritableStreamStartErroring(stream, error).
   StartErroring(aCx, aError, aRv);

   // Step 2.2. Return.
   return;
 }

 // Step 3. Assert: state is "erroring".
 MOZ_ASSERT(mState == WriterState::Erroring);

 // Step 4. Perform ! WritableStreamFinishErroring(stream).
 FinishErroring(aCx, aRv);
}

// https://streams.spec.whatwg.org/#writable-stream-finish-erroring
void WritableStream::FinishErroring(JSContext* aCx, ErrorResult& aRv) {
 // Step 1. Assert: stream.[[state]] is "erroring".
 MOZ_ASSERT(mState == WriterState::Erroring);

 // Step 2. Assert: ! WritableStreamHasOperationMarkedInFlight(stream) is
 // false.
 MOZ_ASSERT(!HasOperationMarkedInFlight());

 // Step 3. Set stream.[[state]] to "errored".
 mState = WriterState::Errored;

 // Step 4. Perform ! stream.[[controller]].[[ErrorSteps]]().
 Controller()->ErrorSteps();

 // Step 5. Let storedError be stream.[[storedError]].
 JS::Rooted<JS::Value> storedError(aCx, mStoredError);

 // Step 6. For each writeRequest of stream.[[writeRequests]]:
 while (!mWriteRequests.IsEmpty()) {
   // Step 6.1. Reject writeRequest with storedError.
   mWriteRequests.Pop()->MaybeReject(storedError);
 }

 // Step 7. Set stream.[[writeRequests]] to an empty list.
 // (Popping should make it empty)

 // Step 8. If stream.[[pendingAbortRequest]] is undefined,
 if (!mPendingAbortRequestPromise) {
   // Step 8.1. Perform !
   // WritableStreamRejectCloseAndClosedPromiseIfNeeded(stream).
   RejectCloseAndClosedPromiseIfNeeded();

   // Step 8.2. Return.
   return;
 }

 // Step 9. Let abortRequest be stream.[[pendingAbortRequest]].
 RefPtr<Promise> abortPromise = mPendingAbortRequestPromise;
 JS::Rooted<JS::Value> abortReason(aCx, mPendingAbortRequestReason);
 bool abortWasAlreadyErroring = mPendingAbortRequestWasAlreadyErroring;

 // Step 10. Set stream.[[pendingAbortRequest]] to undefined.
 SetPendingAbortRequest(nullptr, JS::UndefinedHandleValue, false);

 // Step 11. If abortRequest’s was already erroring is true,
 if (abortWasAlreadyErroring) {
   // Step 11.1. Reject abortRequest’s promise with storedError.
   abortPromise->MaybeReject(storedError);

   // Step 11.2. Perform !
   // WritableStreamRejectCloseAndClosedPromiseIfNeeded(stream).
   RejectCloseAndClosedPromiseIfNeeded();

   // Step 11.3. Return.
   return;
 }

 // Step 12. Let promise be !
 // stream.[[controller]].[[AbortSteps]](abortRequest’s reason).
 RefPtr<WritableStreamDefaultController> controller = mController;
 RefPtr<Promise> promise = controller->AbortSteps(aCx, abortReason, aRv);
 if (aRv.Failed()) {
   return;
 }

 // Step 13 + 14.
 promise->AddCallbacksWithCycleCollectedArgs(
     [](JSContext* aCx, JS::Handle<JS::Value> aValue, ErrorResult& aRv,
        Promise* aAbortRequestPromise, WritableStream* aStream) {
       // Step 13. Upon fulfillment of promise,
       // Step 13.1. Resolve abortRequest’s promise with undefined.
       aAbortRequestPromise->MaybeResolveWithUndefined();

       // Step 13.2. Perform !
       // WritableStreamRejectCloseAndClosedPromiseIfNeeded(stream).
       aStream->RejectCloseAndClosedPromiseIfNeeded();
     },
     [](JSContext* aCx, JS::Handle<JS::Value> aValue, ErrorResult& aRv,
        Promise* aAbortRequestPromise, WritableStream* aStream) {
       // Step 14. Upon rejection of promise with reason reason,
       // Step 14.1. Reject abortRequest’s promise with reason.
       aAbortRequestPromise->MaybeReject(aValue);

       // Step 14.2. Perform !
       // WritableStreamRejectCloseAndClosedPromiseIfNeeded(stream).
       aStream->RejectCloseAndClosedPromiseIfNeeded();
     },
     RefPtr(abortPromise), RefPtr(this));
}

// https://streams.spec.whatwg.org/#writable-stream-finish-in-flight-close
void WritableStream::FinishInFlightClose() {
 // Step 1. Assert: stream.[[inFlightCloseRequest]] is not undefined.
 MOZ_ASSERT(mInFlightCloseRequest);

 // Step 2. Resolve stream.[[inFlightCloseRequest]] with undefined.
 mInFlightCloseRequest->MaybeResolveWithUndefined();

 // Step 3. Set stream.[[inFlightCloseRequest]] to undefined.
 mInFlightCloseRequest = nullptr;

 // Step 4. Let state be stream.[[state]].
 // Step 5. Assert: stream.[[state]] is "writable" or "erroring".
 MOZ_ASSERT(mState == WriterState::Writable ||
            mState == WriterState::Erroring);

 // Step 6. If state is "erroring",
 if (mState == WriterState::Erroring) {
   // Step 6.1. Set stream.[[storedError]] to undefined.
   mStoredError.setUndefined();

   // Step 6.2. If stream.[[pendingAbortRequest]] is not undefined,
   if (mPendingAbortRequestPromise) {
     // Step 6.2.1. Resolve stream.[[pendingAbortRequest]]'s promise with
     // undefined.
     mPendingAbortRequestPromise->MaybeResolveWithUndefined();

     // Step 6.2.2. Set stream.[[pendingAbortRequest]] to undefined.
     SetPendingAbortRequest(nullptr, JS::UndefinedHandleValue, false);
   }
 }

 // Step 7. Set stream.[[state]] to "closed".
 mState = WriterState::Closed;

 // Step 8. Let writer be stream.[[writer]].
 // Step 9. If writer is not undefined, resolve writer.[[closedPromise]] with
 // undefined.
 if (mWriter) {
   mWriter->ClosedPromise()->MaybeResolveWithUndefined();
 }

 // Step 10. Assert: stream.[[pendingAbortRequest]] is undefined.
 MOZ_ASSERT(!mPendingAbortRequestPromise);
 // Assert: stream.[[storedError]] is undefined.
 MOZ_ASSERT(mStoredError.isUndefined());
}

// https://streams.spec.whatwg.org/#writable-stream-finish-in-flight-close-with-error
void WritableStream::FinishInFlightCloseWithError(JSContext* aCx,
                                                 JS::Handle<JS::Value> aError,
                                                 ErrorResult& aRv) {
 // Step 1. Assert: stream.[[inFlightCloseRequest]] is not undefined.
 MOZ_ASSERT(mInFlightCloseRequest);

 // Step 2. Reject stream.[[inFlightCloseRequest]] with error.
 mInFlightCloseRequest->MaybeReject(aError);

 // Step 3. Set stream.[[inFlightCloseRequest]] to undefined.
 mInFlightCloseRequest = nullptr;

 // Step 4. Assert: stream.[[state]] is "writable" or "erroring".
 MOZ_ASSERT(mState == WriterState::Writable ||
            mState == WriterState::Erroring);

 // Step 5. If stream.[[pendingAbortRequest]] is not undefined,
 if (mPendingAbortRequestPromise) {
   // Step 5.1. Reject stream.[[pendingAbortRequest]]'s promise with error.
   mPendingAbortRequestPromise->MaybeReject(aError);

   // Step 5.2. Set stream.[[pendingAbortRequest]] to undefined.
   SetPendingAbortRequest(nullptr, JS::UndefinedHandleValue, false);
 }

 // Step 6. Perform ! WritableStreamDealWithRejection(stream, error).
 DealWithRejection(aCx, aError, aRv);
}

// https://streams.spec.whatwg.org/#writable-stream-finish-in-flight-write
void WritableStream::FinishInFlightWrite() {
 // Step 1. Assert: stream.[[inFlightWriteRequest]] is not undefined.
 MOZ_ASSERT(mInFlightWriteRequest);

 // Step 2. Resolve stream.[[inFlightWriteRequest]] with undefined.
 mInFlightWriteRequest->MaybeResolveWithUndefined();

 // Step 3. Set stream.[[inFlightWriteRequest]] to undefined.
 mInFlightWriteRequest = nullptr;
}

// https://streams.spec.whatwg.org/#writable-stream-finish-in-flight-write-with-error
void WritableStream::FinishInFlightWriteWithError(JSContext* aCx,
                                                 JS::Handle<JS::Value> aError,
                                                 ErrorResult& aRv) {
 // Step 1. Assert: stream.[[inFlightWriteRequest]] is not undefined.
 MOZ_ASSERT(mInFlightWriteRequest);

 // Step 2. Reject stream.[[inFlightWriteRequest]] with error.
 mInFlightWriteRequest->MaybeReject(aError);

 // Step 3. Set stream.[[inFlightWriteRequest]] to undefined.
 mInFlightWriteRequest = nullptr;

 // Step 4. Assert: stream.[[state]] is "writable" or "erroring".
 MOZ_ASSERT(mState == WriterState::Writable ||
            mState == WriterState::Erroring);

 // Step 5. Perform ! WritableStreamDealWithRejection(stream, error).
 DealWithRejection(aCx, aError, aRv);
}

// https://streams.spec.whatwg.org/#writable-stream-mark-close-request-in-flight
void WritableStream::MarkCloseRequestInFlight() {
 // Step 1. Assert: stream.[[inFlightCloseRequest]] is undefined.
 MOZ_ASSERT(!mInFlightCloseRequest);

 // Step 2. Assert: stream.[[closeRequest]] is not undefined.
 MOZ_ASSERT(mCloseRequest);

 // Step 3. Set stream.[[inFlightCloseRequest]] to stream.[[closeRequest]].
 mInFlightCloseRequest = mCloseRequest;

 // Step 4. Set stream.[[closeRequest]] to undefined.
 mCloseRequest = nullptr;
}

// https://streams.spec.whatwg.org/#writable-stream-mark-first-write-request-in-flight
void WritableStream::MarkFirstWriteRequestInFlight() {
 // Step 1. Assert: stream.[[inFlightWriteRequest]] is undefined.
 MOZ_ASSERT(!mInFlightWriteRequest);

 // Step 2. Assert: stream.[[writeRequests]] is not empty.
 MOZ_ASSERT(!mWriteRequests.IsEmpty());

 // Step 3. Let writeRequest be stream.[[writeRequests]][0].
 // Step 4. Remove writeRequest from stream.[[writeRequests]].
 RefPtr<Promise> writeRequest = mWriteRequests.Pop();

 // Step 5. Set stream.[[inFlightWriteRequest]] to writeRequest.
 mInFlightWriteRequest = writeRequest;
}

// https://streams.spec.whatwg.org/#writable-stream-reject-close-and-closed-promise-if-needed
void WritableStream::RejectCloseAndClosedPromiseIfNeeded() {
 // Step 1. Assert: stream.[[state]] is "errored".
 MOZ_ASSERT(mState == WriterState::Errored);

 JS::Rooted<JS::Value> storedError(RootingCx(), mStoredError);
 // Step 2. If stream.[[closeRequest]] is not undefined,
 if (mCloseRequest) {
   // Step 2.1. Assert: stream.[[inFlightCloseRequest]] is undefined.
   MOZ_ASSERT(!mInFlightCloseRequest);

   // Step 2.2. Reject stream.[[closeRequest]] with stream.[[storedError]].
   mCloseRequest->MaybeReject(storedError);

   // Step 2.3. Set stream.[[closeRequest]] to undefined.
   mCloseRequest = nullptr;
 }

 // Step 3. Let writer be stream.[[writer]].
 RefPtr<WritableStreamDefaultWriter> writer = mWriter;

 // Step 4. If writer is not undefined,
 if (writer) {
   // Step 4.1. Reject writer.[[closedPromise]] with stream.[[storedError]].
   RefPtr<Promise> closedPromise = writer->ClosedPromise();
   closedPromise->MaybeReject(storedError);

   // Step 4.2. Set writer.[[closedPromise]].[[PromiseIsHandled]] to true.
   closedPromise->SetSettledPromiseIsHandled();
 }
}

// https://streams.spec.whatwg.org/#writable-stream-start-erroring
void WritableStream::StartErroring(JSContext* aCx,
                                  JS::Handle<JS::Value> aReason,
                                  ErrorResult& aRv) {
 // Step 1. Assert: stream.[[storedError]] is undefined.
 MOZ_ASSERT(mStoredError.isUndefined());

 // Step 2. Assert: stream.[[state]] is "writable".
 MOZ_ASSERT(mState == WriterState::Writable);

 // Step 3. Let controller be stream.[[controller]].
 RefPtr<WritableStreamDefaultController> controller = mController;
 // Step 4. Assert: controller is not undefined.
 MOZ_ASSERT(controller);

 // Step 5. Set stream.[[state]] to "erroring".
 mState = WriterState::Erroring;

 // Step 6. Set stream.[[storedError]] to reason.
 mStoredError = aReason;

 // Step 7. Let writer be stream.[[writer]].
 RefPtr<WritableStreamDefaultWriter> writer = mWriter;
 // Step 8. If writer is not undefined, perform !
 // WritableStreamDefaultWriterEnsureReadyPromiseRejected(writer, reason).
 if (writer) {
   WritableStreamDefaultWriterEnsureReadyPromiseRejected(writer, aReason);
 }

 // Step 9. If ! WritableStreamHasOperationMarkedInFlight(stream) is false
 // and controller.[[started]] is true,
 // perform !WritableStreamFinishErroring(stream).
 if (!HasOperationMarkedInFlight() && controller->Started()) {
   FinishErroring(aCx, aRv);
 }
}

// https://streams.spec.whatwg.org/#writable-stream-update-backpressure
void WritableStream::UpdateBackpressure(bool aBackpressure) {
 // Step 1. Assert: stream.[[state]] is "writable".
 MOZ_ASSERT(mState == WriterState::Writable);
 // Step 2. Assert: ! WritableStreamCloseQueuedOrInFlight(stream) is false.
 MOZ_ASSERT(!CloseQueuedOrInFlight());

 // Step 3. Let writer be stream.[[writer]].
 RefPtr<WritableStreamDefaultWriter> writer = mWriter;

 // Step 4. If writer is not undefined and backpressure is not
 // stream.[[backpressure]],
 if (writer && aBackpressure != mBackpressure) {
   // Step 4.1. If backpressure is true, set writer.[[readyPromise]] to a new
   // promise.
   if (aBackpressure) {
     RefPtr<Promise> promise =
         Promise::CreateInfallible(writer->GetParentObject());
     writer->SetReadyPromise(promise);
   } else {
     // Step 4.2. Otherwise,
     // Step 4.2.1. Assert: backpressure is false.
     // Step 4.2.2. Resolve writer.[[readyPromise]] with undefined.
     writer->ReadyPromise()->MaybeResolveWithUndefined();
   }
 }

 // Step 5. Set stream.[[backpressure]] to backpressure.
 mBackpressure = aBackpressure;
}

// https://streams.spec.whatwg.org/#ws-constructor
already_AddRefed<WritableStream> WritableStream::Constructor(
   const GlobalObject& aGlobal,
   const Optional<JS::Handle<JSObject*>>& aUnderlyingSink,
   const QueuingStrategy& aStrategy, ErrorResult& aRv) {
 // Step 1. If underlyingSink is missing, set it to null.
 JS::Rooted<JSObject*> underlyingSinkObj(
     aGlobal.Context(),
     aUnderlyingSink.WasPassed() ? aUnderlyingSink.Value() : nullptr);

 // Step 2. Let underlyingSinkDict be underlyingSink, converted to
 //         an IDL value of type UnderlyingSink.
 RootedDictionary<UnderlyingSink> underlyingSinkDict(aGlobal.Context());
 if (underlyingSinkObj) {
   JS::Rooted<JS::Value> objValue(aGlobal.Context(),
                                  JS::ObjectValue(*underlyingSinkObj));
   dom::BindingCallContext callCx(aGlobal.Context(),
                                  "WritableStream.constructor");
   aRv.MightThrowJSException();
   if (!underlyingSinkDict.Init(callCx, objValue)) {
     aRv.StealExceptionFromJSContext(aGlobal.Context());
     return nullptr;
   }
 }

 // Step 3. If underlyingSinkDict["type"] exists, throw a RangeError exception.
 if (!underlyingSinkDict.mType.isUndefined()) {
   aRv.ThrowRangeError("Implementation preserved member 'type'");
   return nullptr;
 }

 // Step 4. Perform ! InitializeWritableStream(this).
 RefPtr<WritableStream> writableStream =
     new WritableStream(aGlobal, HoldDropJSObjectsCaller::Implicit);

 // Step 5. Let sizeAlgorithm be ! ExtractSizeAlgorithm(strategy).
 //
 // Implementation Note: The specification demands that if the size doesn't
 // exist, we instead would provide an algorithm that returns 1. Instead, we
 // will teach callers that a missing callback should simply return 1, rather
 // than gin up a fake callback here.
 //
 // This decision may need to be revisited if the default action ever diverges
 // within the specification.
 RefPtr<QueuingStrategySize> sizeAlgorithm =
     aStrategy.mSize.WasPassed() ? &aStrategy.mSize.Value() : nullptr;

 // Step 6. Let highWaterMark be ? ExtractHighWaterMark(strategy, 1).
 double highWaterMark = ExtractHighWaterMark(aStrategy, 1, aRv);
 if (aRv.Failed()) {
   return nullptr;
 }

 // Step 7. Perform ? SetUpWritableStreamDefaultControllerFromUnderlyingSink(
 // this, underlyingSink, underlyingSinkDict, highWaterMark, sizeAlgorithm).
 SetUpWritableStreamDefaultControllerFromUnderlyingSink(
     aGlobal.Context(), writableStream, underlyingSinkObj, underlyingSinkDict,
     highWaterMark, sizeAlgorithm, aRv);
 if (aRv.Failed()) {
   return nullptr;
 }

 return writableStream.forget();
}

namespace streams_abstract {
// https://streams.spec.whatwg.org/#writable-stream-abort
already_AddRefed<Promise> WritableStreamAbort(JSContext* aCx,
                                             WritableStream* aStream,
                                             JS::Handle<JS::Value> aReason,
                                             ErrorResult& aRv) {
 // Step 1. If stream.[[state]] is "closed" or "errored", return a promise
 // resolved with undefined.
 if (aStream->State() == WritableStream::WriterState::Closed ||
     aStream->State() == WritableStream::WriterState::Errored) {
   RefPtr<Promise> promise =
       Promise::CreateInfallible(aStream->GetParentObject());
   promise->MaybeResolveWithUndefined();
   return promise.forget();
 }

 // Step 2. Signal abort on stream.[[controller]].[[signal]] with reason.
 RefPtr<WritableStreamDefaultController> controller = aStream->Controller();
 controller->Signal()->SignalAbort(aReason);

 // Step 3. Let state be stream.[[state]].
 WritableStream::WriterState state = aStream->State();

 // Step 4. If state is "closed" or "errored", return a promise resolved with
 // undefined. Note: We re-check the state because signaling abort runs author
 // code and that might have changed the state.
 if (aStream->State() == WritableStream::WriterState::Closed ||
     aStream->State() == WritableStream::WriterState::Errored) {
   RefPtr<Promise> promise =
       Promise::CreateInfallible(aStream->GetParentObject());
   promise->MaybeResolveWithUndefined();
   return promise.forget();
 }

 // Step 5. If stream.[[pendingAbortRequest]] is not undefined, return
 // stream.[[pendingAbortRequest]]'s promise.
 if (aStream->GetPendingAbortRequestPromise()) {
   RefPtr<Promise> promise = aStream->GetPendingAbortRequestPromise();
   return promise.forget();
 }

 // Step 6. Assert: state is "writable" or "erroring".
 MOZ_ASSERT(state == WritableStream::WriterState::Writable ||
            state == WritableStream::WriterState::Erroring);

 // Step 7. Let wasAlreadyErroring be false.
 bool wasAlreadyErroring = false;

 // Step 8. If state is "erroring",
 JS::Rooted<JS::Value> reason(aCx, aReason);
 if (state == WritableStream::WriterState::Erroring) {
   // Step 8.1. Set wasAlreadyErroring to true.
   wasAlreadyErroring = true;
   // Step 8.2. Set reason to undefined.
   reason.setUndefined();
 }

 // Step 9. Let promise be a new promise.
 RefPtr<Promise> promise =
     Promise::CreateInfallible(aStream->GetParentObject());

 // Step 10. Set stream.[[pendingAbortRequest]] to a new pending abort request
 // whose promise is promise, reason is reason, and was already erroring is
 // wasAlreadyErroring.
 aStream->SetPendingAbortRequest(promise, reason, wasAlreadyErroring);

 // Step 11. If wasAlreadyErroring is false, perform !
 // WritableStreamStartErroring(stream, reason).
 if (!wasAlreadyErroring) {
   aStream->StartErroring(aCx, reason, aRv);
   if (aRv.Failed()) {
     return nullptr;
   }
 }

 // Step 12. Return promise.
 return promise.forget();
}
}  // namespace streams_abstract

// https://streams.spec.whatwg.org/#ws-abort
already_AddRefed<Promise> WritableStream::Abort(JSContext* aCx,
                                               JS::Handle<JS::Value> aReason,
                                               ErrorResult& aRv) {
 // Step 1. If ! IsWritableStreamLocked(this) is true, return a promise
 // rejected with a TypeError exception.
 if (Locked()) {
   return Promise::CreateRejectedWithTypeError(
       GetParentObject(), "Canceled Locked Stream"_ns, aRv);
 }

 // Step 2. Return ! WritableStreamAbort(this, reason).
 RefPtr<WritableStream> thisRefPtr = this;
 return WritableStreamAbort(aCx, thisRefPtr, aReason, aRv);
}

namespace streams_abstract {
// https://streams.spec.whatwg.org/#writable-stream-close
already_AddRefed<Promise> WritableStreamClose(JSContext* aCx,
                                             WritableStream* aStream,
                                             ErrorResult& aRv) {
 // Step 1. Let state be stream.[[state]].
 WritableStream::WriterState state = aStream->State();

 // Step 2. If state is "closed" or "errored", return a promise rejected with a
 // TypeError exception.
 if (state == WritableStream::WriterState::Closed ||
     state == WritableStream::WriterState::Errored) {
   return Promise::CreateRejectedWithTypeError(
       aStream->GetParentObject(),
       "Can not close stream after closing or error"_ns, aRv);
 }

 // Step 3. Assert: state is "writable" or "erroring".
 MOZ_ASSERT(state == WritableStream::WriterState::Writable ||
            state == WritableStream::WriterState::Erroring);

 // Step 4. Assert: ! WritableStreamCloseQueuedOrInFlight(stream) is false.
 MOZ_ASSERT(!aStream->CloseQueuedOrInFlight());

 // Step 5. Let promise be a new promise.
 RefPtr<Promise> promise =
     Promise::CreateInfallible(aStream->GetParentObject());

 // Step 6. Set stream.[[closeRequest]] to promise.
 aStream->SetCloseRequest(promise);

 // Step 7. Let writer be stream.[[writer]].
 RefPtr<WritableStreamDefaultWriter> writer = aStream->GetWriter();

 // Step 8. If writer is not undefined, and stream.[[backpressure]] is true,
 // and state is "writable", resolve writer.[[readyPromise]] with undefined.
 if (writer && aStream->Backpressure() &&
     state == WritableStream::WriterState::Writable) {
   writer->ReadyPromise()->MaybeResolveWithUndefined();
 }

 // Step 9.
 // Perform ! WritableStreamDefaultControllerClose(stream.[[controller]]).
 RefPtr<WritableStreamDefaultController> controller = aStream->Controller();
 WritableStreamDefaultControllerClose(aCx, controller, aRv);
 if (aRv.Failed()) {
   return nullptr;
 }

 // Step 10. Return promise.
 return promise.forget();
}
}  // namespace streams_abstract

// https://streams.spec.whatwg.org/#ws-close
already_AddRefed<Promise> WritableStream::Close(JSContext* aCx,
                                               ErrorResult& aRv) {
 // Step 1. If ! IsWritableStreamLocked(this) is true, return a promise
 // rejected with a TypeError exception.
 if (Locked()) {
   return Promise::CreateRejectedWithTypeError(
       GetParentObject(), "Can not close locked stream"_ns, aRv);
 }

 // Step 2. If ! WritableStreamCloseQueuedOrInFlight(this) is true, return a
 // promise rejected with a TypeError exception.
 if (CloseQueuedOrInFlight()) {
   return Promise::CreateRejectedWithTypeError(
       GetParentObject(), "Stream is already closing"_ns, aRv);
 }

 // Step 3. Return ! WritableStreamClose(this).
 RefPtr<WritableStream> thisRefPtr = this;
 return WritableStreamClose(aCx, thisRefPtr, aRv);
}

namespace streams_abstract {
// https://streams.spec.whatwg.org/#acquire-writable-stream-default-writer
already_AddRefed<WritableStreamDefaultWriter>
AcquireWritableStreamDefaultWriter(WritableStream* aStream, ErrorResult& aRv) {
 // Step 1. Let writer be a new WritableStreamDefaultWriter.
 RefPtr<WritableStreamDefaultWriter> writer =
     new WritableStreamDefaultWriter(aStream->GetParentObject());

 // Step 2. Perform ? SetUpWritableStreamDefaultWriter(writer, stream).
 SetUpWritableStreamDefaultWriter(writer, aStream, aRv);
 if (aRv.Failed()) {
   return nullptr;
 }

 // Step 3. Return writer.
 return writer.forget();
}
}  // namespace streams_abstract

// https://streams.spec.whatwg.org/#create-writable-stream
already_AddRefed<WritableStream> WritableStream::CreateAbstract(
   JSContext* aCx, nsIGlobalObject* aGlobal,
   UnderlyingSinkAlgorithmsBase* aAlgorithms, double aHighWaterMark,
   QueuingStrategySize* aSizeAlgorithm, ErrorResult& aRv) {
 // Step 1: Assert: ! IsNonNegativeNumber(highWaterMark) is true.
 MOZ_ASSERT(IsNonNegativeNumber(aHighWaterMark));

 // Step 2: Let stream be a new WritableStream.
 // Step 3: Perform ! InitializeWritableStream(stream).
 RefPtr<WritableStream> stream = new WritableStream(
     aGlobal, WritableStream::HoldDropJSObjectsCaller::Implicit);

 // Step 4: Let controller be a new WritableStreamDefaultController.
 auto controller =
     MakeRefPtr<WritableStreamDefaultController>(aGlobal, *stream);

 // Step 5: Perform ? SetUpWritableStreamDefaultController(stream, controller,
 // startAlgorithm, writeAlgorithm, closeAlgorithm, abortAlgorithm,
 // highWaterMark, sizeAlgorithm).
 SetUpWritableStreamDefaultController(aCx, stream, controller, aAlgorithms,
                                      aHighWaterMark, aSizeAlgorithm, aRv);
 if (aRv.Failed()) {
   return nullptr;
 }

 // Step 6: Return stream.
 return stream.forget();
}

already_AddRefed<WritableStreamDefaultWriter> WritableStream::GetWriter(
   ErrorResult& aRv) {
 return AcquireWritableStreamDefaultWriter(this, aRv);
}

namespace streams_abstract {
// https://streams.spec.whatwg.org/#writable-stream-add-write-request
already_AddRefed<Promise> WritableStreamAddWriteRequest(
   WritableStream* aStream) {
 // Step 1. Assert: ! IsWritableStreamLocked(stream) is true.
 MOZ_ASSERT(IsWritableStreamLocked(aStream));

 // Step 2. Assert: stream.[[state]] is "writable".
 MOZ_ASSERT(aStream->State() == WritableStream::WriterState::Writable);

 // Step 3. Let promise be a new promise.
 RefPtr<Promise> promise =
     Promise::CreateInfallible(aStream->GetParentObject());

 // Step 4. Append promise to stream.[[writeRequests]].
 aStream->AppendWriteRequest(promise);

 // Step 5. Return promise.
 return promise.forget();
}
}  // namespace streams_abstract

// https://streams.spec.whatwg.org/#writablestream-set-up
// _BOUNDARY because `aAlgorithms->StartCallback` (called by
// SetUpWritableStreamDefaultController below) should not be able to run script
// in this case.
MOZ_CAN_RUN_SCRIPT_BOUNDARY void WritableStream::SetUpNative(
   JSContext* aCx, UnderlyingSinkAlgorithmsWrapper& aAlgorithms,
   Maybe<double> aHighWaterMark, QueuingStrategySize* aSizeAlgorithm,
   ErrorResult& aRv) {
 // an optional number highWaterMark (default 1)
 double highWaterMark = aHighWaterMark.valueOr(1);
 // and if given, highWaterMark must be a non-negative, non-NaN number.
 MOZ_ASSERT(IsNonNegativeNumber(highWaterMark));

 // Step 1: Let startAlgorithm be an algorithm that returns undefined.
 // Step 2: Let closeAlgorithmWrapper be an algorithm that runs these steps:
 // Step 3: Let abortAlgorithmWrapper be an algorithm that runs these steps:
 // (Covered by UnderlyingSinkAlgorithmsWrapper)

 // Step 4: If sizeAlgorithm was not given, then set it to an algorithm that
 // returns 1. (Callers will treat nullptr as such, see
 // WritableStream::Constructor for details)

 // Step 5: Perform ! InitializeWritableStream(stream).
 // (Covered by the constructor)

 // Step 6: Let controller be a new WritableStreamDefaultController.
 auto controller =
     MakeRefPtr<WritableStreamDefaultController>(GetParentObject(), *this);

 // Step 7: Perform ! SetUpWritableStreamDefaultController(stream, controller,
 // startAlgorithm, writeAlgorithm, closeAlgorithmWrapper,
 // abortAlgorithmWrapper, highWaterMark, sizeAlgorithm).
 SetUpWritableStreamDefaultController(aCx, this, controller, &aAlgorithms,
                                      highWaterMark, aSizeAlgorithm, aRv);
}

already_AddRefed<WritableStream> WritableStream::CreateNative(
   JSContext* aCx, nsIGlobalObject& aGlobal,
   UnderlyingSinkAlgorithmsWrapper& aAlgorithms, Maybe<double> aHighWaterMark,
   QueuingStrategySize* aSizeAlgorithm, ErrorResult& aRv) {
 RefPtr<WritableStream> stream = new WritableStream(
     &aGlobal, WritableStream::HoldDropJSObjectsCaller::Implicit);
 stream->SetUpNative(aCx, aAlgorithms, aHighWaterMark, aSizeAlgorithm, aRv);
 if (aRv.Failed()) {
   return nullptr;
 }
 return stream.forget();
}

// https://streams.spec.whatwg.org/#writablestream-error
// To error a WritableStream stream given a JavaScript value e, perform !
// WritableStreamDefaultControllerErrorIfNeeded(stream.[[controller]], e).
void WritableStream::ErrorNative(JSContext* aCx, JS::Handle<JS::Value> aError,
                                ErrorResult& aRv) {
 // MOZ_KnownLive here instead of MOZ_KNOWN_LIVE at the field, because
 // mController is set outside of the constructor
 WritableStreamDefaultControllerErrorIfNeeded(aCx, MOZ_KnownLive(mController),
                                              aError, aRv);
}

}  // namespace mozilla::dom