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/* -*- 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/TransformStreamDefaultController.h"
#include "TransformerCallbackHelpers.h"
#include "mozilla/Attributes.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/ReadableStream.h"
#include "mozilla/dom/ReadableStreamDefaultController.h"
#include "mozilla/dom/TransformStream.h"
#include "mozilla/dom/TransformStreamDefaultControllerBinding.h"
#include "nsWrapperCache.h"
namespace mozilla::dom {
using namespace streams_abstract;
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(TransformStreamDefaultController, mGlobal,
mStream, mTransformerAlgorithms)
NS_IMPL_CYCLE_COLLECTING_ADDREF(TransformStreamDefaultController)
NS_IMPL_CYCLE_COLLECTING_RELEASE(TransformStreamDefaultController)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TransformStreamDefaultController)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
TransformStream* TransformStreamDefaultController::Stream() { return mStream; }
void TransformStreamDefaultController::SetStream(TransformStream& aStream) {
MOZ_ASSERT(!mStream);
mStream = &aStream;
}
TransformerAlgorithmsBase* TransformStreamDefaultController::Algorithms() {
return mTransformerAlgorithms;
}
void TransformStreamDefaultController::SetAlgorithms(
TransformerAlgorithmsBase* aTransformerAlgorithms) {
mTransformerAlgorithms = aTransformerAlgorithms;
}
TransformStreamDefaultController::TransformStreamDefaultController(
nsIGlobalObject* aGlobal)
: mGlobal(aGlobal) {
mozilla::HoldJSObjects(this);
}
TransformStreamDefaultController::~TransformStreamDefaultController() {
mozilla::DropJSObjects(this);
}
JSObject* TransformStreamDefaultController::WrapObject(
JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
return TransformStreamDefaultController_Binding::Wrap(aCx, this, aGivenProto);
}
// https://streams.spec.whatwg.org/#ts-default-controller-desired-size
Nullable<double> TransformStreamDefaultController::GetDesiredSize() const {
// Step 1. Let readableController be
// this.[[stream]].[[readable]].[[controller]].
RefPtr<ReadableStreamDefaultController> readableController =
mStream->Readable()->Controller()->AsDefault();
// Step 2. Return !
// ReadableStreamDefaultControllerGetDesiredSize(readableController).
return ReadableStreamDefaultControllerGetDesiredSize(readableController);
}
// https://streams.spec.whatwg.org/#rs-default-controller-has-backpressure
// Looks like a readable stream thing but the spec explicitly says this is for
// TransformStream.
static bool ReadableStreamDefaultControllerHasBackpressure(
ReadableStreamDefaultController* aController) {
// Step 1: If ! ReadableStreamDefaultControllerShouldCallPull(controller) is
// true, return false.
// Step 2: Otherwise, return true.
return !ReadableStreamDefaultControllerShouldCallPull(aController);
}
void TransformStreamDefaultController::Enqueue(JSContext* aCx,
JS::Handle<JS::Value> aChunk,
ErrorResult& aRv) {
// Step 1: Perform ? TransformStreamDefaultControllerEnqueue(this, chunk).
// Inlining TransformStreamDefaultControllerEnqueue here.
// https://streams.spec.whatwg.org/#transform-stream-default-controller-enqueue
// Step 1: Let stream be controller.[[stream]].
RefPtr<TransformStream> stream = mStream;
// Step 2: Let readableController be stream.[[readable]].[[controller]].
RefPtr<ReadableStreamDefaultController> readableController =
stream->Readable()->Controller()->AsDefault();
// Step 3: If !
// ReadableStreamDefaultControllerCanCloseOrEnqueue(readableController) is
// false, throw a TypeError exception.
if (!ReadableStreamDefaultControllerCanCloseOrEnqueueAndThrow(
readableController, CloseOrEnqueue::Enqueue, aRv)) {
return;
}
// Step 4: Let enqueueResult be
// ReadableStreamDefaultControllerEnqueue(readableController, chunk).
ErrorResult rv;
ReadableStreamDefaultControllerEnqueue(aCx, readableController, aChunk, rv);
// Step 5: If enqueueResult is an abrupt completion,
if (rv.MaybeSetPendingException(aCx)) {
JS::Rooted<JS::Value> error(aCx);
if (!JS_GetPendingException(aCx, &error)) {
// Uncatchable exception; we should mark aRv and return.
aRv.StealExceptionFromJSContext(aCx);
return;
}
JS_ClearPendingException(aCx);
// Step 5.1: Perform ! TransformStreamErrorWritableAndUnblockWrite(stream,
// enqueueResult.[[Value]]).
TransformStreamErrorWritableAndUnblockWrite(aCx, stream, error, aRv);
// Step 5.2: Throw stream.[[readable]].[[storedError]].
JS::Rooted<JS::Value> storedError(aCx, stream->Readable()->StoredError());
aRv.MightThrowJSException();
aRv.ThrowJSException(aCx, storedError);
return;
}
// Step 6: Let backpressure be !
// ReadableStreamDefaultControllerHasBackpressure(readableController).
bool backpressure =
ReadableStreamDefaultControllerHasBackpressure(readableController);
// Step 7: If backpressure is not stream.[[backpressure]],
if (backpressure != stream->Backpressure()) {
// Step 7.1: Assert: backpressure is true.
MOZ_ASSERT(backpressure);
// Step 7.2: Perform ! TransformStreamSetBackpressure(true).
stream->SetBackpressure(true);
}
}
// https://streams.spec.whatwg.org/#ts-default-controller-error
void TransformStreamDefaultController::Error(JSContext* aCx,
JS::Handle<JS::Value> aError,
ErrorResult& aRv) {
// Step 1: Perform ? TransformStreamDefaultControllerError(this, e).
// Inlining TransformStreamDefaultControllerError here.
// https://streams.spec.whatwg.org/#transform-stream-default-controller-error
// Perform ! TransformStreamError(controller.[[stream]], e).
// mStream is set in initialization step and only modified in cycle
// collection.
// TODO: Move mStream initialization to a method/constructor and make it
// MOZ_KNOWN_LIVE again. (See bug 1769854)
TransformStreamError(aCx, MOZ_KnownLive(mStream), aError, aRv);
}
// https://streams.spec.whatwg.org/#ts-default-controller-terminate
void TransformStreamDefaultController::Terminate(JSContext* aCx,
ErrorResult& aRv) {
// Step 1: Perform ? TransformStreamDefaultControllerTerminate(this).
// Inlining TransformStreamDefaultControllerTerminate here.
// https://streams.spec.whatwg.org/#transform-stream-default-controller-terminate
// Step 1: Let stream be controller.[[stream]].
RefPtr<TransformStream> stream = mStream;
// Step 2: Let readableController be stream.[[readable]].[[controller]].
RefPtr<ReadableStreamDefaultController> readableController =
stream->Readable()->Controller()->AsDefault();
// Step 3: Perform ! ReadableStreamDefaultControllerClose(readableController).
ReadableStreamDefaultControllerClose(aCx, readableController, aRv);
// Step 4: Let error be a TypeError exception indicating that the stream has
// been terminated.
ErrorResult rv;
rv.ThrowTypeError("Terminating the stream");
JS::Rooted<JS::Value> error(aCx);
MOZ_ALWAYS_TRUE(ToJSValue(aCx, std::move(rv), &error));
// Step 5: Perform ! TransformStreamErrorWritableAndUnblockWrite(stream,
// error).
TransformStreamErrorWritableAndUnblockWrite(aCx, stream, error, aRv);
}
namespace streams_abstract {
// https://streams.spec.whatwg.org/#set-up-transform-stream-default-controller
void SetUpTransformStreamDefaultController(
JSContext* aCx, TransformStream& aStream,
TransformStreamDefaultController& aController,
TransformerAlgorithmsBase& aTransformerAlgorithms) {
// Step 1. Assert: stream implements TransformStream.
// Step 2. Assert: stream.[[controller]] is undefined.
MOZ_ASSERT(!aStream.Controller());
// Step 3. Set controller.[[stream]] to stream.
aController.SetStream(aStream);
// Step 4. Set stream.[[controller]] to controller.
aStream.SetController(aController);
// Step 5. Set controller.[[transformAlgorithm]] to transformAlgorithm.
// Step 6. Set controller.[[flushAlgorithm]] to flushAlgorithm.
aController.SetAlgorithms(&aTransformerAlgorithms);
}
// https://streams.spec.whatwg.org/#set-up-transform-stream-default-controller-from-transformer
void SetUpTransformStreamDefaultControllerFromTransformer(
JSContext* aCx, TransformStream& aStream,
JS::Handle<JSObject*> aTransformer, Transformer& aTransformerDict) {
// Step 1. Let controller be a new TransformStreamDefaultController.
auto controller =
MakeRefPtr<TransformStreamDefaultController>(aStream.GetParentObject());
// Step 2 - 5:
auto algorithms = MakeRefPtr<TransformerAlgorithms>(
aStream.GetParentObject(), aTransformer, aTransformerDict);
// Step 6: Perform ! SetUpTransformStreamDefaultController(stream, controller,
// transformAlgorithm, flushAlgorithm).
SetUpTransformStreamDefaultController(aCx, aStream, *controller, *algorithms);
}
} // namespace streams_abstract
} // namespace mozilla::dom
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