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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
#include "mozilla/dom/ReadableStream.h"
#include "ReadIntoRequest.h"
#include "ReadableStreamPipeTo.h"
#include "ReadableStreamTee.h"
#include "StreamUtils.h"
#include "TeeState.h"
#include "js/Array.h"
#include "js/Exception.h"
#include "js/PropertyAndElement.h"
#include "js/TypeDecls.h"
#include "js/Value.h"
#include "js/Iterator.h"
#include "mozilla/AlreadyAddRefed.h"
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/CycleCollectedJSContext.h"
#include "mozilla/HoldDropJSObjects.h"
#include "mozilla/StaticPrefs_dom.h"
#include "mozilla/dom/BindingCallContext.h"
#include "mozilla/dom/ByteStreamHelpers.h"
#include "mozilla/dom/QueueWithSizes.h"
#include "mozilla/dom/QueuingStrategyBinding.h"
#include "mozilla/dom/ReadRequest.h"
#include "mozilla/dom/ReadableByteStreamController.h"
#include "mozilla/dom/ReadableStreamBYOBReader.h"
#include "mozilla/dom/ReadableStreamBYOBRequest.h"
#include "mozilla/dom/ReadableStreamBinding.h"
#include "mozilla/dom/ReadableStreamController.h"
#include "mozilla/dom/ReadableStreamDefaultController.h"
#include "mozilla/dom/ReadableStreamDefaultReader.h"
#include "mozilla/dom/RootedDictionary.h"
#include "mozilla/dom/ScriptSettings.h"
#include "mozilla/dom/UnderlyingSourceBinding.h"
#include "mozilla/dom/UnderlyingSourceCallbackHelpers.h"
#include "mozilla/dom/WritableStream.h"
#include "mozilla/dom/WritableStreamDefaultWriter.h"
#include "nsCOMPtr.h"
#include "mozilla/dom/Promise-inl.h"
#include "nsIGlobalObject.h"
#include "nsISupports.h"
inline void ImplCycleCollectionTraverse(
nsCycleCollectionTraversalCallback& aCallback,
mozilla::Variant<mozilla::Nothing,
RefPtr<mozilla::dom::ReadableStreamDefaultReader>>&
aReader,
const char* aName, uint32_t aFlags = 0) {
if (aReader.is<RefPtr<mozilla::dom::ReadableStreamDefaultReader>>()) {
ImplCycleCollectionTraverse(
aCallback,
aReader.as<RefPtr<mozilla::dom::ReadableStreamDefaultReader>>(), aName,
aFlags);
}
}
inline void ImplCycleCollectionUnlink(
mozilla::Variant<mozilla::Nothing,
RefPtr<mozilla::dom::ReadableStreamDefaultReader>>&
aReader) {
aReader = AsVariant(mozilla::Nothing());
}
namespace mozilla::dom {
using namespace streams_abstract;
// Only needed for refcounted objects.
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_WITH_JS_MEMBERS(
ReadableStream, (mGlobal, mController, mReader), (mStoredError))
NS_IMPL_CYCLE_COLLECTING_ADDREF(ReadableStream)
NS_IMPL_CYCLE_COLLECTING_RELEASE(ReadableStream)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ReadableStream)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
ReadableStream::ReadableStream(nsIGlobalObject* aGlobal,
HoldDropJSObjectsCaller aHoldDropCaller)
: mGlobal(aGlobal), mReader(nullptr), mHoldDropCaller(aHoldDropCaller) {
if (mHoldDropCaller == HoldDropJSObjectsCaller::Implicit) {
mozilla::HoldJSObjects(this);
}
}
ReadableStream::ReadableStream(const GlobalObject& aGlobal,
HoldDropJSObjectsCaller aHoldDropCaller)
: mGlobal(do_QueryInterface(aGlobal.GetAsSupports())),
mReader(nullptr),
mHoldDropCaller(aHoldDropCaller) {
if (mHoldDropCaller == HoldDropJSObjectsCaller::Implicit) {
mozilla::HoldJSObjects(this);
}
}
ReadableStream::~ReadableStream() {
if (mHoldDropCaller == HoldDropJSObjectsCaller::Implicit) {
mozilla::DropJSObjects(this);
}
}
JSObject* ReadableStream::WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return ReadableStream_Binding::Wrap(aCx, this, aGivenProto);
}
ReadableStreamDefaultReader* ReadableStream::GetDefaultReader() {
return mReader->AsDefault();
}
void ReadableStream::SetReader(ReadableStreamGenericReader* aReader) {
mReader = aReader;
}
namespace streams_abstract {
bool ReadableStreamHasBYOBReader(ReadableStream* aStream) {
// Step 1. Let reader be stream.[[reader]].
ReadableStreamGenericReader* reader = aStream->GetReader();
// Step 2. If reader is undefined, return false.
if (!reader) {
return false;
}
// Step 3. If reader implements ReadableStreamBYOBReader, return true.
// Step 4. Return false.
return reader->IsBYOB();
}
bool ReadableStreamHasDefaultReader(ReadableStream* aStream) {
// Step 1. Let reader be stream.[[reader]].
ReadableStreamGenericReader* reader = aStream->GetReader();
// Step 2. If reader is undefined, return false.
if (!reader) {
return false;
}
// Step 3. If reader implements ReadableStreamDefaultReader, return true.
// Step 4. Return false.
return reader->IsDefault();
}
} // namespace streams_abstract
/* static */
already_AddRefed<ReadableStream> ReadableStream::Constructor(
const GlobalObject& aGlobal,
const Optional<JS::Handle<JSObject*>>& aUnderlyingSource,
const QueuingStrategy& aStrategy, ErrorResult& aRv) {
// Step 1.
JS::Rooted<JSObject*> underlyingSourceObj(
aGlobal.Context(),
aUnderlyingSource.WasPassed() ? aUnderlyingSource.Value() : nullptr);
// Step 2.
RootedDictionary<UnderlyingSource> underlyingSourceDict(aGlobal.Context());
if (underlyingSourceObj) {
JS::Rooted<JS::Value> objValue(aGlobal.Context(),
JS::ObjectValue(*underlyingSourceObj));
dom::BindingCallContext callCx(aGlobal.Context(),
"ReadableStream.constructor");
aRv.MightThrowJSException();
if (!underlyingSourceDict.Init(callCx, objValue)) {
aRv.StealExceptionFromJSContext(aGlobal.Context());
return nullptr;
}
}
// Step 3.
RefPtr<ReadableStream> readableStream =
new ReadableStream(aGlobal, HoldDropJSObjectsCaller::Implicit);
// Step 4.
if (underlyingSourceDict.mType.WasPassed()) {
// Implicit assertion on above check.
MOZ_ASSERT(underlyingSourceDict.mType.Value() == ReadableStreamType::Bytes);
// Step 4.1
if (aStrategy.mSize.WasPassed()) {
aRv.ThrowRangeError("Implementation preserved member 'size'");
return nullptr;
}
// Step 4.2
double highWaterMark = ExtractHighWaterMark(aStrategy, 0, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 4.3
SetUpReadableByteStreamControllerFromUnderlyingSource(
aGlobal.Context(), readableStream, underlyingSourceObj,
underlyingSourceDict, highWaterMark, aRv);
if (aRv.Failed()) {
return nullptr;
}
return readableStream.forget();
}
// Step 5.1 (implicit in above check)
// Step 5.2. Extract callback.
//
// 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 5.3
double highWaterMark = ExtractHighWaterMark(aStrategy, 1, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 5.4.
SetupReadableStreamDefaultControllerFromUnderlyingSource(
aGlobal.Context(), readableStream, underlyingSourceObj,
underlyingSourceDict, highWaterMark, sizeAlgorithm, aRv);
if (aRv.Failed()) {
return nullptr;
}
return readableStream.forget();
}
class ReadableStreamFromAlgorithms final
: public UnderlyingSourceAlgorithmsWrapper {
public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(
ReadableStreamFromAlgorithms, UnderlyingSourceAlgorithmsWrapper)
ReadableStreamFromAlgorithms(nsIGlobalObject* aGlobal,
JS::Handle<JSObject*> aIteratorRecord)
: mGlobal(aGlobal), mIteratorRecordMaybeCrossRealm(aIteratorRecord) {
mozilla::HoldJSObjects(this);
};
// Step 3. Let startAlgorithm be an algorithm that returns undefined.
// Note: Provided by UnderlyingSourceAlgorithmsWrapper::StartCallback.
// Step 4. Let pullAlgorithm be the following steps:
MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> PullCallbackImpl(
JSContext* aCx, ReadableStreamController& aController,
ErrorResult& aRv) override {
aRv.MightThrowJSException();
JS::Rooted<JSObject*> iteratorRecord(aCx, mIteratorRecordMaybeCrossRealm);
JSAutoRealm ar(aCx, iteratorRecord);
// Step 1. Let nextResult be IteratorNext(iteratorRecord).
JS::Rooted<JS::Value> nextResult(aCx);
if (!JS::IteratorNext(aCx, iteratorRecord, &nextResult)) {
// Step 2. If nextResult is an abrupt completion, return a promise
// rejected with nextResult.[[Value]].
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
// Step 3. Let nextPromise be a promise resolved with nextResult.[[Value]].
RefPtr<Promise> nextPromise = Promise::CreateInfallible(mGlobal);
nextPromise->MaybeResolve(nextResult);
// Step 4. Return the result of reacting to nextPromise with the following
// fulfillment steps, given iterResult:
auto result = nextPromise->ThenWithCycleCollectedArgs(
[](JSContext* aCx, JS::Handle<JS::Value> aIterResult, ErrorResult& aRv,
const RefPtr<ReadableStreamDefaultController>& aController)
MOZ_CAN_RUN_SCRIPT_FOR_DEFINITION -> already_AddRefed<Promise> {
aRv.MightThrowJSException();
// Step 4.1. If Type(iterResult) is not Object, throw a TypeError.
if (!aIterResult.isObject()) {
aRv.ThrowTypeError("next() returned a non-object value");
return nullptr;
}
JS::Rooted<JSObject*> iterResult(aCx, &aIterResult.toObject());
// Step 4.2. Let done be ? IteratorComplete(iterResult).
bool done = false;
if (!JS::IteratorComplete(aCx, iterResult, &done)) {
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
// Step 4.3. If done is true:
if (done) {
// Step 4.3.1. Perform !
// ReadableStreamDefaultControllerClose(stream.[[controller]]).
ReadableStreamDefaultControllerClose(aCx, aController, aRv);
} else {
// Step 4.4. Otherwise:
// Step 4.4.1. Let value be ? IteratorValue(iterResult).
JS::Rooted<JS::Value> value(aCx);
if (!JS::IteratorValue(aCx, iterResult, &value)) {
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
// Step 4.4.2. Perform !
// ReadableStreamDefaultControllerEnqueue(stream.[[controller]],
// value).
ReadableStreamDefaultControllerEnqueue(aCx, aController, value,
aRv);
}
return nullptr;
},
RefPtr(aController.AsDefault()));
if (result.isErr()) {
aRv.Throw(result.unwrapErr());
return nullptr;
}
return result.unwrap().forget();
};
// Step 5. Let cancelAlgorithm be the following steps, given reason:
MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> CancelCallbackImpl(
JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
ErrorResult& aRv) override {
aRv.MightThrowJSException();
JS::Rooted<JSObject*> iteratorRecord(aCx, mIteratorRecordMaybeCrossRealm);
JSAutoRealm ar(aCx, iteratorRecord);
// Step 1. Let iterator be iteratorRecord.[[Iterator]].
JS::Rooted<JS::Value> iterator(aCx);
if (!JS::GetIteratorRecordIterator(aCx, iteratorRecord, &iterator)) {
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
// Step 2. Let returnMethod be GetMethod(iterator, "return").
JS::Rooted<JS::Value> returnMethod(aCx);
if (!JS::GetReturnMethod(aCx, iterator, &returnMethod)) {
// Step 3. If returnMethod is an abrupt completion, return a promise
// rejected with returnMethod.[[Value]].
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
// Step 4. If returnMethod.[[Value]] is undefined, return a promise resolved
// with undefined.
if (returnMethod.isUndefined()) {
return Promise::CreateResolvedWithUndefined(mGlobal, aRv);
}
// Step 5. Let returnResult be Call(returnMethod.[[Value]], iterator, «
// reason »).
JS::Rooted<JS::Value> reason(aCx, aReason.Value());
if (!JS_WrapValue(aCx, &reason)) {
JS_ClearPendingException(aCx);
aRv.Throw(NS_ERROR_UNEXPECTED);
return nullptr;
}
JS::Rooted<JS::Value> returnResult(aCx);
if (!JS::Call(aCx, iterator, returnMethod, JS::HandleValueArray(reason),
&returnResult)) {
// Step 6. If returnResult is an abrupt completion, return a promise
// rejected with returnResult.[[Value]].
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
// Step 7. Let returnPromise be a promise resolved with
// returnResult.[[Value]].
RefPtr<Promise> returnPromise = Promise::CreateInfallible(mGlobal);
returnPromise->MaybeResolve(returnResult);
// Step 8. Return the result of reacting to returnPromise with the following
// fulfillment steps, given iterResult:
auto result = returnPromise->ThenWithCycleCollectedArgs(
[](JSContext* aCx, JS::Handle<JS::Value> aIterResult, ErrorResult& aRv)
MOZ_CAN_RUN_SCRIPT_FOR_DEFINITION -> already_AddRefed<Promise> {
// Step 8.1. If Type(iterResult) is not Object, throw a TypeError.
if (!aIterResult.isObject()) {
aRv.ThrowTypeError("return() returned a non-object value");
return nullptr;
}
// Step 8.2. Return undefined.
return nullptr;
});
if (result.isErr()) {
aRv.Throw(result.unwrapErr());
return nullptr;
}
return result.unwrap().forget();
};
protected:
~ReadableStreamFromAlgorithms() override { mozilla::DropJSObjects(this); };
private:
// Virtually const, but are cycle collected
nsCOMPtr<nsIGlobalObject> mGlobal;
JS::Heap<JSObject*> mIteratorRecordMaybeCrossRealm;
};
NS_IMPL_CYCLE_COLLECTION_INHERITED_WITH_JS_MEMBERS(
ReadableStreamFromAlgorithms, UnderlyingSourceAlgorithmsWrapper, (mGlobal),
(mIteratorRecordMaybeCrossRealm))
NS_IMPL_ADDREF_INHERITED(ReadableStreamFromAlgorithms,
UnderlyingSourceAlgorithmsWrapper)
NS_IMPL_RELEASE_INHERITED(ReadableStreamFromAlgorithms,
UnderlyingSourceAlgorithmsWrapper)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ReadableStreamFromAlgorithms)
NS_INTERFACE_MAP_END_INHERITING(UnderlyingSourceAlgorithmsWrapper)
static already_AddRefed<ReadableStream> MOZ_CAN_RUN_SCRIPT
ReadableStreamFromIterable(JSContext* aCx, nsIGlobalObject* aGlobal,
JS::Handle<JS::Value> aAsyncIterable,
ErrorResult& aRv) {
aRv.MightThrowJSException();
// Step 1. Let stream be undefined. (not required)
// Step 2. Let iteratorRecord be ? GetIterator(asyncIterable, async).
JS::Rooted<JSObject*> iteratorRecord(
aCx, JS::GetIteratorObject(aCx, aAsyncIterable, true));
if (!iteratorRecord) {
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
// Steps 3-5. are in ReadableStreamFromAlgorithms.
auto algorithms =
MakeRefPtr<ReadableStreamFromAlgorithms>(aGlobal, iteratorRecord);
// Step 6. Set stream to ! CreateReadableStream(startAlgorithm, pullAlgorithm,
// cancelAlgorithm, 0).
// Step 7. Return stream.
return ReadableStream::CreateAbstract(aCx, aGlobal, algorithms,
mozilla::Some(0.0), nullptr, aRv);
}
/* static */
already_AddRefed<ReadableStream> ReadableStream::From(
const GlobalObject& aGlobal, JS::Handle<JS::Value> aAsyncIterable,
ErrorResult& aRv) {
// Step 1. Return ? ReadableStreamFromIterable(asyncIterable).
nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
return ReadableStreamFromIterable(aGlobal.Context(), global, aAsyncIterable,
aRv);
}
// Dealing with const this ptr is a pain, so just re-implement.
bool ReadableStream::Locked() const {
// Step 1 + 2.
return mReader;
}
namespace streams_abstract {
static void InitializeReadableStream(ReadableStream* aStream) {
// Step 1.
aStream->SetState(ReadableStream::ReaderState::Readable);
// Step 2.
aStream->SetReader(nullptr);
aStream->SetStoredError(JS::UndefinedHandleValue);
// Step 3.
aStream->SetDisturbed(false);
}
} // namespace streams_abstract
MOZ_CAN_RUN_SCRIPT
already_AddRefed<ReadableStream> ReadableStream::CreateAbstract(
JSContext* aCx, nsIGlobalObject* aGlobal,
UnderlyingSourceAlgorithmsBase* aAlgorithms,
mozilla::Maybe<double> aHighWaterMark, QueuingStrategySize* aSizeAlgorithm,
ErrorResult& aRv) {
// Step 1. If highWaterMark was not passed, set it to 1.
double highWaterMark = aHighWaterMark.valueOr(1.0);
// Step 2. consumers of sizeAlgorithm
// handle null algorithms correctly.
// Step 3.
MOZ_ASSERT(IsNonNegativeNumber(highWaterMark));
// Step 4.
RefPtr<ReadableStream> stream =
new ReadableStream(aGlobal, HoldDropJSObjectsCaller::Implicit);
// Step 5.
InitializeReadableStream(stream);
// Step 6.
RefPtr<ReadableStreamDefaultController> controller =
new ReadableStreamDefaultController(aGlobal);
// Step 7.
SetUpReadableStreamDefaultController(aCx, stream, controller, aAlgorithms,
highWaterMark, aSizeAlgorithm, aRv);
// Step 8.
return stream.forget();
}
namespace streams_abstract {
void ReadableStreamClose(JSContext* aCx, ReadableStream* aStream,
ErrorResult& aRv) {
// Step 1.
MOZ_ASSERT(aStream->State() == ReadableStream::ReaderState::Readable);
// Step 2.
aStream->SetState(ReadableStream::ReaderState::Closed);
// Step 3.
ReadableStreamGenericReader* reader = aStream->GetReader();
// Step 4.
if (!reader) {
return;
}
// Step 5.
reader->ClosedPromise()->MaybeResolveWithUndefined();
// Step 6.
if (reader->IsDefault()) {
// Step 6.1. Let readRequests be reader.[[readRequests]].
// Move LinkedList out of DefaultReader onto stack to avoid the potential
// for concurrent modification, which could invalidate the iterator.
//
// example of the kind of issue that could occur.
LinkedList<RefPtr<ReadRequest>> readRequests =
std::move(reader->AsDefault()->ReadRequests());
// Step 6.2. Set reader.[[readRequests]] to an empty list.
// Note: The std::move already cleared this anyway.
reader->AsDefault()->ReadRequests().clear();
// Step 6.3. For each readRequest of readRequests,
// Drain the local list and destroy elements along the way.
while (RefPtr<ReadRequest> readRequest = readRequests.popFirst()) {
// Step 6.3.1. Perform readRequest’s close steps.
readRequest->CloseSteps(aCx, aRv);
if (aRv.Failed()) {
return;
}
}
}
}
already_AddRefed<Promise> ReadableStreamCancel(JSContext* aCx,
ReadableStream* aStream,
JS::Handle<JS::Value> aError,
ErrorResult& aRv) {
// Step 1.
aStream->SetDisturbed(true);
// Step 2.
if (aStream->State() == ReadableStream::ReaderState::Closed) {
RefPtr<Promise> promise =
Promise::CreateInfallible(aStream->GetParentObject());
promise->MaybeResolveWithUndefined();
return promise.forget();
}
// Step 3.
if (aStream->State() == ReadableStream::ReaderState::Errored) {
JS::Rooted<JS::Value> storedError(aCx, aStream->StoredError());
return Promise::CreateRejected(aStream->GetParentObject(), storedError,
aRv);
}
// Step 4.
ReadableStreamClose(aCx, aStream, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 5.
ReadableStreamGenericReader* reader = aStream->GetReader();
// Step 6.
if (reader && reader->IsBYOB()) {
// Step 6.1. Let readIntoRequests be reader.[[readIntoRequests]].
LinkedList<RefPtr<ReadIntoRequest>> readIntoRequests =
std::move(reader->AsBYOB()->ReadIntoRequests());
// Step 6.2. Set reader.[[readIntoRequests]] to an empty list.
// Note: The std::move already cleared this anyway.
reader->AsBYOB()->ReadIntoRequests().clear();
// Step 6.3. For each readIntoRequest of readIntoRequests,
while (RefPtr<ReadIntoRequest> readIntoRequest =
readIntoRequests.popFirst()) {
// Step 6.3.1.Perform readIntoRequest’s close steps, given undefined.
readIntoRequest->CloseSteps(aCx, JS::UndefinedHandleValue, aRv);
if (aRv.Failed()) {
return nullptr;
}
}
}
// Step 7.
RefPtr<ReadableStreamController> controller(aStream->Controller());
RefPtr<Promise> sourceCancelPromise =
controller->CancelSteps(aCx, aError, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 8.
RefPtr<Promise> promise =
Promise::CreateInfallible(sourceCancelPromise->GetParentObject());
// ThenWithCycleCollectedArgs will carry promise, keeping it alive until the
// callback executes.
Result<RefPtr<Promise>, nsresult> returnResult =
sourceCancelPromise->ThenWithCycleCollectedArgs(
[](JSContext*, JS::Handle<JS::Value>, ErrorResult&,
RefPtr<Promise> newPromise) {
newPromise->MaybeResolveWithUndefined();
return newPromise.forget();
},
promise);
if (returnResult.isErr()) {
aRv.Throw(returnResult.unwrapErr());
return nullptr;
}
return returnResult.unwrap().forget();
}
} // namespace streams_abstract
already_AddRefed<Promise> ReadableStream::Cancel(JSContext* aCx,
JS::Handle<JS::Value> aReason,
ErrorResult& aRv) {
// Step 1. If ! IsReadableStreamLocked(this) is true,
// return a promise rejected with a TypeError exception.
if (Locked()) {
aRv.ThrowTypeError("Cannot cancel a stream locked by a reader.");
return nullptr;
}
// Step 2. Return ! ReadableStreamCancel(this, reason).
RefPtr<ReadableStream> thisRefPtr = this;
return ReadableStreamCancel(aCx, thisRefPtr, aReason, aRv);
}
namespace streams_abstract {
already_AddRefed<ReadableStreamDefaultReader>
AcquireReadableStreamDefaultReader(ReadableStream* aStream, ErrorResult& aRv) {
// Step 1.
RefPtr<ReadableStreamDefaultReader> reader =
new ReadableStreamDefaultReader(aStream->GetParentObject());
// Step 2.
SetUpReadableStreamDefaultReader(reader, aStream, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 3.
return reader.forget();
}
} // namespace streams_abstract
void ReadableStream::GetReader(const ReadableStreamGetReaderOptions& aOptions,
OwningReadableStreamReader& resultReader,
ErrorResult& aRv) {
// Step 1. If options["mode"] does not exist,
// return ? AcquireReadableStreamDefaultReader(this).
if (!aOptions.mMode.WasPassed()) {
RefPtr<ReadableStreamDefaultReader> defaultReader =
AcquireReadableStreamDefaultReader(this, aRv);
if (aRv.Failed()) {
return;
}
resultReader.SetAsReadableStreamDefaultReader() = defaultReader;
return;
}
// Step 2. Assert: options["mode"] is "byob".
MOZ_ASSERT(aOptions.mMode.Value() == ReadableStreamReaderMode::Byob);
// Step 3. Return ? AcquireReadableStreamBYOBReader(this).
RefPtr<ReadableStreamBYOBReader> byobReader =
AcquireReadableStreamBYOBReader(this, aRv);
if (aRv.Failed()) {
return;
}
resultReader.SetAsReadableStreamBYOBReader() = byobReader;
}
namespace streams_abstract {
bool IsReadableStreamLocked(ReadableStream* aStream) {
// Step 1 + 2.
return aStream->Locked();
}
} // namespace streams_abstract
MOZ_CAN_RUN_SCRIPT already_AddRefed<ReadableStream> ReadableStream::PipeThrough(
const ReadableWritablePair& aTransform, const StreamPipeOptions& aOptions,
ErrorResult& aRv) {
// Step 1: If ! IsReadableStreamLocked(this) is true, throw a TypeError
// exception.
if (IsReadableStreamLocked(this)) {
aRv.ThrowTypeError("Cannot pipe from a locked stream.");
return nullptr;
}
// Step 2: If ! IsWritableStreamLocked(transform["writable"]) is true, throw a
// TypeError exception.
if (IsWritableStreamLocked(aTransform.mWritable)) {
aRv.ThrowTypeError("Cannot pipe to a locked stream.");
return nullptr;
}
// Step 3: Let signal be options["signal"] if it exists, or undefined
// otherwise.
RefPtr<AbortSignal> signal =
aOptions.mSignal.WasPassed() ? &aOptions.mSignal.Value() : nullptr;
// Step 4: Let promise be ! ReadableStreamPipeTo(this, transform["writable"],
// options["preventClose"], options["preventAbort"], options["preventCancel"],
// signal).
RefPtr<WritableStream> writable = aTransform.mWritable;
RefPtr<Promise> promise = ReadableStreamPipeTo(
this, writable, aOptions.mPreventClose, aOptions.mPreventAbort,
aOptions.mPreventCancel, signal, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 5: Set promise.[[PromiseIsHandled]] to true.
MOZ_ALWAYS_TRUE(promise->SetAnyPromiseIsHandled());
// Step 6: Return transform["readable"].
return do_AddRef(aTransform.mReadable.get());
};
namespace streams_abstract {
double ReadableStreamGetNumReadRequests(ReadableStream* aStream) {
// Step 1.
MOZ_ASSERT(ReadableStreamHasDefaultReader(aStream));
// Step 2.
return double(aStream->GetDefaultReader()->ReadRequests().length());
}
void ReadableStreamError(JSContext* aCx, ReadableStream* aStream,
JS::Handle<JS::Value> aValue, ErrorResult& aRv) {
// Step 1.
MOZ_ASSERT(aStream->State() == ReadableStream::ReaderState::Readable);
// Step 2.
aStream->SetState(ReadableStream::ReaderState::Errored);
// Step 3.
aStream->SetStoredError(aValue);
// Step 4.
ReadableStreamGenericReader* reader = aStream->GetReader();
// Step 5.
if (!reader) {
return;
}
// Step 6.
reader->ClosedPromise()->MaybeReject(aValue);
// Step 7.
reader->ClosedPromise()->SetSettledPromiseIsHandled();
// Step 8.
if (reader->IsDefault()) {
// Step 8.1. Perform ! ReadableStreamDefaultReaderErrorReadRequests(reader,
// e).
RefPtr<ReadableStreamDefaultReader> defaultReader = reader->AsDefault();
ReadableStreamDefaultReaderErrorReadRequests(aCx, defaultReader, aValue,
aRv);
if (aRv.Failed()) {
return;
}
} else {
// Step 9. Otherwise,
// Step 9.1. Assert: reader implements ReadableStreamBYOBReader.
MOZ_ASSERT(reader->IsBYOB());
// Step 9.2. Perform ! ReadableStreamBYOBReaderErrorReadIntoRequests(reader,
// e).
RefPtr<ReadableStreamBYOBReader> byobReader = reader->AsBYOB();
ReadableStreamBYOBReaderErrorReadIntoRequests(aCx, byobReader, aValue, aRv);
if (aRv.Failed()) {
return;
}
}
}
void ReadableStreamFulfillReadRequest(JSContext* aCx, ReadableStream* aStream,
JS::Handle<JS::Value> aChunk, bool aDone,
ErrorResult& aRv) {
// Step 1.
MOZ_ASSERT(ReadableStreamHasDefaultReader(aStream));
// Step 2.
ReadableStreamDefaultReader* reader = aStream->GetDefaultReader();
// Step 3.
MOZ_ASSERT(!reader->ReadRequests().isEmpty());
// Step 4+5.
RefPtr<ReadRequest> readRequest = reader->ReadRequests().popFirst();
// Step 6.
if (aDone) {
readRequest->CloseSteps(aCx, aRv);
if (aRv.Failed()) {
return;
}
}
// Step 7.
readRequest->ChunkSteps(aCx, aChunk, aRv);
}
void ReadableStreamAddReadRequest(ReadableStream* aStream,
ReadRequest* aReadRequest) {
// Step 1.
MOZ_ASSERT(aStream->GetReader()->IsDefault());
// Step 2.
MOZ_ASSERT(aStream->State() == ReadableStream::ReaderState::Readable);
// Step 3.
aStream->GetDefaultReader()->ReadRequests().insertBack(aReadRequest);
}
} // namespace streams_abstract
// Step 14, 15
MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise>
ReadableStreamDefaultTeeSourceAlgorithms::CancelCallback(
JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
ErrorResult& aRv) {
// Step 1.
mTeeState->SetCanceled(mBranch, true);
// Step 2.
mTeeState->SetReason(mBranch, aReason.Value());
// Step 3.
if (mTeeState->Canceled(OtherTeeBranch(mBranch))) {
// Step 3.1
JS::Rooted<JSObject*> compositeReason(aCx, JS::NewArrayObject(aCx, 2));
if (!compositeReason) {
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
JS::Rooted<JS::Value> reason1(aCx, mTeeState->Reason1());
if (!JS_SetElement(aCx, compositeReason, 0, reason1)) {
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
JS::Rooted<JS::Value> reason2(aCx, mTeeState->Reason2());
if (!JS_SetElement(aCx, compositeReason, 1, reason2)) {
aRv.StealExceptionFromJSContext(aCx);
return nullptr;
}
// Step 3.2
JS::Rooted<JS::Value> compositeReasonValue(
aCx, JS::ObjectValue(*compositeReason));
RefPtr<ReadableStream> stream(mTeeState->GetStream());
RefPtr<Promise> cancelResult =
ReadableStreamCancel(aCx, stream, compositeReasonValue, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 3.3
mTeeState->CancelPromise()->MaybeResolve(cancelResult);
}
// Step 4.
return do_AddRef(mTeeState->CancelPromise());
}
MOZ_CAN_RUN_SCRIPT
static void ReadableStreamDefaultTee(JSContext* aCx, ReadableStream* aStream,
bool aCloneForBranch2,
nsTArray<RefPtr<ReadableStream>>& aResult,
ErrorResult& aRv) {
// Step 1. Implicit.
// Step 2. Implicit.
// Steps 3-12 are contained in the construction of Tee State.
RefPtr<TeeState> teeState = TeeState::Create(aStream, aCloneForBranch2, aRv);
if (aRv.Failed()) {
return;
}
// Step 13 - 16
auto branch1Algorithms = MakeRefPtr<ReadableStreamDefaultTeeSourceAlgorithms>(
teeState, TeeBranch::Branch1);
auto branch2Algorithms = MakeRefPtr<ReadableStreamDefaultTeeSourceAlgorithms>(
teeState, TeeBranch::Branch2);
// Step 17.
nsCOMPtr<nsIGlobalObject> global(
do_AddRef(teeState->GetStream()->GetParentObject()));
teeState->SetBranch1(ReadableStream::CreateAbstract(
aCx, global, branch1Algorithms, mozilla::Nothing(), nullptr, aRv));
if (aRv.Failed()) {
return;
}
// Step 18.
teeState->SetBranch2(ReadableStream::CreateAbstract(
aCx, global, branch2Algorithms, mozilla::Nothing(), nullptr, aRv));
if (aRv.Failed()) {
return;
}
// Step 19.
teeState->GetReader()->ClosedPromise()->AddCallbacksWithCycleCollectedArgs(
[](JSContext* aCx, JS::Handle<JS::Value> aValue, ErrorResult& aRv,
TeeState* aTeeState) {},
[](JSContext* aCx, JS::Handle<JS::Value> aReason, ErrorResult& aRv,
TeeState* aTeeState) {
// Step 19.1.
ReadableStreamDefaultControllerError(
aCx, aTeeState->Branch1()->DefaultController(), aReason, aRv);
if (aRv.Failed()) {
return;
}
// Step 19.2
ReadableStreamDefaultControllerError(
aCx, aTeeState->Branch2()->DefaultController(), aReason, aRv);
if (aRv.Failed()) {
return;
}
// Step 19.3
if (!aTeeState->Canceled1() || !aTeeState->Canceled2()) {
aTeeState->CancelPromise()->MaybeResolveWithUndefined();
}
},
RefPtr(teeState));
// Step 20.
aResult.AppendElement(teeState->Branch1());
aResult.AppendElement(teeState->Branch2());
}
already_AddRefed<Promise> ReadableStream::PipeTo(
WritableStream& aDestination, const StreamPipeOptions& aOptions,
ErrorResult& aRv) {
// Step 1. If !IsReadableStreamLocked(this) is true, return a promise rejected
// with a TypeError exception.
if (IsReadableStreamLocked(this)) {
aRv.ThrowTypeError("Cannot pipe from a locked stream.");
return nullptr;
}
// Step 2. If !IsWritableStreamLocked(destination) is true, return a promise
// rejected with a TypeError exception.
if (IsWritableStreamLocked(&aDestination)) {
aRv.ThrowTypeError("Cannot pipe to a locked stream.");
return nullptr;
}
// Step 3. Let signal be options["signal"] if it exists, or undefined
// otherwise.
RefPtr<AbortSignal> signal =
aOptions.mSignal.WasPassed() ? &aOptions.mSignal.Value() : nullptr;
// Step 4. Return ! ReadableStreamPipeTo(this, destination,
// options["preventClose"], options["preventAbort"], options["preventCancel"],
// signal).
return ReadableStreamPipeTo(this, &aDestination, aOptions.mPreventClose,
aOptions.mPreventAbort, aOptions.mPreventCancel,
signal, aRv);
}
MOZ_CAN_RUN_SCRIPT
static void ReadableStreamTee(JSContext* aCx, ReadableStream* aStream,
bool aCloneForBranch2,
nsTArray<RefPtr<ReadableStream>>& aResult,
ErrorResult& aRv) {
// Step 1. Implicit.
// Step 2. Implicit.
// Step 3.
if (aStream->Controller()->IsByte()) {
ReadableByteStreamTee(aCx, aStream, aResult, aRv);
return;
}
// Step 4.
ReadableStreamDefaultTee(aCx, aStream, aCloneForBranch2, aResult, aRv);
}
void ReadableStream::Tee(JSContext* aCx,
nsTArray<RefPtr<ReadableStream>>& aResult,
ErrorResult& aRv) {
ReadableStreamTee(aCx, this, false, aResult, aRv);
}
void ReadableStream::IteratorData::Traverse(
nsCycleCollectionTraversalCallback& cb) {
ReadableStream::IteratorData* tmp = this;
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mReader);
}
void ReadableStream::IteratorData::Unlink() {
ReadableStream::IteratorData* tmp = this;
NS_IMPL_CYCLE_COLLECTION_UNLINK(mReader);
}
void ReadableStream::InitAsyncIteratorData(
IteratorData& aData, Iterator::IteratorType aType,
const ReadableStreamIteratorOptions& aOptions, ErrorResult& aRv) {
// Step 1. Let reader be ? AcquireReadableStreamDefaultReader(stream).
RefPtr<ReadableStreamDefaultReader> reader =
AcquireReadableStreamDefaultReader(this, aRv);
if (aRv.Failed()) {
return;
}
// Step 2. Set iterator’s reader to reader.
aData.mReader = reader;
// Step 3. Let preventCancel be args[0]["preventCancel"].
// Step 4. Set iterator’s prevent cancel to preventCancel.
aData.mPreventCancel = aOptions.mPreventCancel;
}
// Step 4.
struct IteratorReadRequest : public ReadRequest {
public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(IteratorReadRequest, ReadRequest)
RefPtr<Promise> mPromise;
RefPtr<ReadableStreamDefaultReader> mReader;
explicit IteratorReadRequest(Promise* aPromise,
ReadableStreamDefaultReader* aReader)
: mPromise(aPromise), mReader(aReader) {}
// chunk steps, given chunk
void ChunkSteps(JSContext* aCx, JS::Handle<JS::Value> aChunk,
ErrorResult& aRv) override {
// Step 1. Resolve promise with chunk.
mPromise->MaybeResolve(aChunk);
}
// close steps
void CloseSteps(JSContext* aCx, ErrorResult& aRv) override {
// Step 1. Perform ! ReadableStreamDefaultReaderRelease(reader).
ReadableStreamDefaultReaderRelease(aCx, mReader, aRv);
if (aRv.Failed()) {
mPromise->MaybeRejectWithUndefined();
return;
}
// Step 2. Resolve promise with end of iteration.
iterator_utils::ResolvePromiseForFinished(mPromise);
}
// error steps, given e
void ErrorSteps(JSContext* aCx, JS::Handle<JS::Value> aError,
ErrorResult& aRv) override {
// Step 1. Perform ! ReadableStreamDefaultReaderRelease(reader).
ReadableStreamDefaultReaderRelease(aCx, mReader, aRv);
if (aRv.Failed()) {
mPromise->MaybeRejectWithUndefined();
return;
}
// Step 2. Reject promise with e.
mPromise->MaybeReject(aError);
}
protected:
virtual ~IteratorReadRequest() = default;
};
NS_IMPL_CYCLE_COLLECTION_INHERITED(IteratorReadRequest, ReadRequest, mPromise,
mReader)
NS_IMPL_ADDREF_INHERITED(IteratorReadRequest, ReadRequest)
NS_IMPL_RELEASE_INHERITED(IteratorReadRequest, ReadRequest)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(IteratorReadRequest)
NS_INTERFACE_MAP_END_INHERITING(ReadRequest)
already_AddRefed<Promise> ReadableStream::GetNextIterationResult(
Iterator* aIterator, ErrorResult& aRv) {
// Step 1. Let reader be iterator’s reader.
RefPtr<ReadableStreamDefaultReader> reader = aIterator->Data().mReader;
// Step 2. Assert: reader.[[stream]] is not undefined.
MOZ_ASSERT(reader->GetStream());
// Step 3. Let promise be a new promise.
RefPtr<Promise> promise = Promise::CreateInfallible(GetParentObject());
// Step 4. Let readRequest be a new read request with the following items:
RefPtr<ReadRequest> request = new IteratorReadRequest(promise, reader);
// Step 5. Perform ! ReadableStreamDefaultReaderRead(this, readRequest).
AutoJSAPI jsapi;
if (!jsapi.Init(mGlobal)) {
aRv.ThrowUnknownError("Internal error");
return nullptr;
}
ReadableStreamDefaultReaderRead(jsapi.cx(), reader, request, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 6. Return promise.
return promise.forget();
}
already_AddRefed<Promise> ReadableStream::IteratorReturn(
JSContext* aCx, Iterator* aIterator, JS::Handle<JS::Value> aValue,
ErrorResult& aRv) {
// Step 1. Let reader be iterator’s reader.
RefPtr<ReadableStreamDefaultReader> reader = aIterator->Data().mReader;
// Step 2. Assert: reader.[[stream]] is not undefined.
MOZ_ASSERT(reader->GetStream());
// Step 3. Assert: reader.[[readRequests]] is empty, as the async iterator
// machinery guarantees that any previous calls to next() have settled before
// this is called.
MOZ_ASSERT(reader->ReadRequests().isEmpty());
// Step 4. If iterator’s prevent cancel is false:
if (!aIterator->Data().mPreventCancel) {
// Step 4.1. Let result be ! ReadableStreamReaderGenericCancel(reader, arg).
RefPtr<ReadableStream> stream(reader->GetStream());
RefPtr<Promise> result = ReadableStreamCancel(aCx, stream, aValue, aRv);
if (NS_WARN_IF(aRv.Failed())) {
return nullptr;
}
MOZ_DIAGNOSTIC_ASSERT(
reader->GetStream(),
if (!reader->GetStream()) {
aRv.Throw(NS_ERROR_FAILURE);
return nullptr;
}
// Step 4.2. Perform ! ReadableStreamDefaultReaderRelease(reader).
ReadableStreamDefaultReaderRelease(aCx, reader, aRv);
if (NS_WARN_IF(aRv.Failed())) {
return nullptr;
}
// Step 4.3. Return result.
return result.forget();
}
// Step 5. Perform ! ReadableStreamDefaultReaderRelease(reader).
ReadableStreamDefaultReaderRelease(aCx, reader, aRv);
if (NS_WARN_IF(aRv.Failed())) {
return nullptr;
}
// Step 6. Return a promise resolved with undefined.
return Promise::CreateResolvedWithUndefined(GetParentObject(), aRv);
}
namespace streams_abstract {
void ReadableStreamAddReadIntoRequest(ReadableStream* aStream,
ReadIntoRequest* aReadIntoRequest) {
// Step 1. Assert: stream.[[reader]] implements ReadableStreamBYOBReader.
MOZ_ASSERT(aStream->GetReader()->IsBYOB());
// Step 2. Assert: stream.[[state]] is "readable" or "closed".
MOZ_ASSERT(aStream->State() == ReadableStream::ReaderState::Readable ||
aStream->State() == ReadableStream::ReaderState::Closed);
// Step 3. Append readRequest to stream.[[reader]].[[readIntoRequests]].
aStream->GetReader()->AsBYOB()->ReadIntoRequests().insertBack(
aReadIntoRequest);
}
} // namespace streams_abstract
already_AddRefed<ReadableStream> ReadableStream::CreateByteAbstract(
JSContext* aCx, nsIGlobalObject* aGlobal,
UnderlyingSourceAlgorithmsBase* aAlgorithms, ErrorResult& aRv) {
// Step 1. Let stream be a new ReadableStream.
RefPtr<ReadableStream> stream =
new ReadableStream(aGlobal, HoldDropJSObjectsCaller::Implicit);
// Step 2. Perform ! InitializeReadableStream(stream).
InitializeReadableStream(stream);
// Step 3. Let controller be a new ReadableByteStreamController.
RefPtr<ReadableByteStreamController> controller =
new ReadableByteStreamController(aGlobal);
// Step 4. Perform ? SetUpReadableByteStreamController(stream, controller,
// startAlgorithm, pullAlgorithm, cancelAlgorithm, 0, undefined).
SetUpReadableByteStreamController(aCx, stream, controller, aAlgorithms, 0,
mozilla::Nothing(), aRv);
if (aRv.Failed()) {
return nullptr;
}
// Return stream.
return stream.forget();
}
// (except this instead creates a new ReadableStream rather than accepting an
// existing instance)
// _BOUNDARY because `aAlgorithms->StartCallback` (called by
// SetUpReadableStreamDefaultController below) should not be able to run script
// in this case.
MOZ_CAN_RUN_SCRIPT_BOUNDARY already_AddRefed<ReadableStream>
ReadableStream::CreateNative(JSContext* aCx, nsIGlobalObject* aGlobal,
UnderlyingSourceAlgorithmsWrapper& aAlgorithms,
mozilla::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 pullAlgorithmWrapper be an algorithm that runs these steps:
// Step 3: Let cancelAlgorithmWrapper be an algorithm that runs these steps:
// (Done by UnderlyingSourceAlgorithmsWrapper)
// Step 4: If sizeAlgorithm was not given, then set it to an algorithm that
// returns 1. (Callers will treat nullptr as such, see
// ReadableStream::Constructor for details)
// Step 5: Perform ! InitializeReadableStream(stream).
RefPtr<ReadableStream> stream =
new ReadableStream(aGlobal, HoldDropJSObjectsCaller::Implicit);
// Step 6: Let controller be a new ReadableStreamDefaultController.
auto controller = MakeRefPtr<ReadableStreamDefaultController>(aGlobal);
// Step 7: Perform ! SetUpReadableStreamDefaultController(stream, controller,
// startAlgorithm, pullAlgorithmWrapper, cancelAlgorithmWrapper,
// highWaterMark, sizeAlgorithm).
SetUpReadableStreamDefaultController(aCx, stream, controller, &aAlgorithms,
highWaterMark, aSizeAlgorithm, aRv);
if (aRv.Failed()) {
return nullptr;
}
return stream.forget();
}
// _BOUNDARY because `aAlgorithms->StartCallback` (called by
// SetUpReadableByteStreamController below) should not be able to run script in
// this case.
MOZ_CAN_RUN_SCRIPT_BOUNDARY void ReadableStream::SetUpByteNative(
JSContext* aCx, UnderlyingSourceAlgorithmsWrapper& aAlgorithms,
mozilla::Maybe<double> aHighWaterMark, ErrorResult& aRv) {
// an optional number highWaterMark (default 0)
double highWaterMark = aHighWaterMark.valueOr(0);
// 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 pullAlgorithmWrapper be an algorithm that runs these steps:
// Step 3: Let cancelAlgorithmWrapper be an algorithm that runs these steps:
// (Done by UnderlyingSourceAlgorithmsWrapper)
// Step 4: Perform ! InitializeReadableStream(stream).
// (Covered by constructor)
// Step 5: Let controller be a new ReadableByteStreamController.
auto controller = MakeRefPtr<ReadableByteStreamController>(GetParentObject());
// Step 6: Perform ! SetUpReadableByteStreamController(stream, controller,
// startAlgorithm, pullAlgorithmWrapper, cancelAlgorithmWrapper,
// highWaterMark, undefined).
SetUpReadableByteStreamController(aCx, this, controller, &aAlgorithms,
highWaterMark, Nothing(), aRv);
}
already_AddRefed<ReadableStream> ReadableStream::CreateByteNative(
JSContext* aCx, nsIGlobalObject* aGlobal,
UnderlyingSourceAlgorithmsWrapper& aAlgorithms,
mozilla::Maybe<double> aHighWaterMark, ErrorResult& aRv) {
RefPtr<ReadableStream> stream =
new ReadableStream(aGlobal, HoldDropJSObjectsCaller::Implicit);
stream->SetUpByteNative(aCx, aAlgorithms, aHighWaterMark, aRv);
if (aRv.Failed()) {
return nullptr;
}
return stream.forget();
}
void ReadableStream::CloseNative(JSContext* aCx, ErrorResult& aRv) {
MOZ_ASSERT_IF(mController->GetAlgorithms(),
mController->GetAlgorithms()->IsNative());
// Step 1: If stream.[[controller]] implements ReadableByteStreamController,
if (mController->IsByte()) {
RefPtr<ReadableByteStreamController> controller = mController->AsByte();
// Step 1.1: Perform !
// ReadableByteStreamControllerClose(stream.[[controller]]).
ReadableByteStreamControllerClose(aCx, controller, aRv);
if (aRv.Failed()) {
return;
}
// Step 1.2: If stream.[[controller]].[[pendingPullIntos]] is not empty,
// perform ! ReadableByteStreamControllerRespond(stream.[[controller]], 0).
if (!controller->PendingPullIntos().isEmpty()) {
ReadableByteStreamControllerRespond(aCx, controller, 0, aRv);
}
return;
}
// Step 2: Otherwise, perform !
// ReadableStreamDefaultControllerClose(stream.[[controller]]).
RefPtr<ReadableStreamDefaultController> controller = mController->AsDefault();
ReadableStreamDefaultControllerClose(aCx, controller, aRv);
}
void ReadableStream::ErrorNative(JSContext* aCx, JS::Handle<JS::Value> aError,
ErrorResult& aRv) {
// Step 1: If stream.[[controller]] implements ReadableByteStreamController,
// then perform ! ReadableByteStreamControllerError(stream.[[controller]], e).
if (mController->IsByte()) {
ReadableByteStreamControllerError(mController->AsByte(), aError, aRv);
return;
}
// Step 2: Otherwise, perform !
// ReadableStreamDefaultControllerError(stream.[[controller]], e).
ReadableStreamDefaultControllerError(aCx, mController->AsDefault(), aError,
aRv);
}
static void CurrentBYOBRequestView(JSContext* aCx,
ReadableByteStreamController& aController,
JS::MutableHandle<JSObject*> aRetVal,
ErrorResult& aRv) {
// Step 1. Assert: stream.[[controller]] implements
// ReadableByteStreamController. (implicit)
// Step 2: Let byobRequest be !
// ReadableByteStreamControllerGetBYOBRequest(stream.[[controller]]).
RefPtr<ReadableStreamBYOBRequest> byobRequest =
ReadableByteStreamControllerGetBYOBRequest(aCx, &aController, aRv);
// Step 3: If byobRequest is null, then return null.
if (!byobRequest) {
aRetVal.set(nullptr);
return;
}
// Step 4: Return byobRequest.[[view]].
byobRequest->GetView(aCx, aRetVal);
}
static bool HasSameBufferView(JSContext* aCx, JS::Handle<JSObject*> aX,
JS::Handle<JSObject*> aY, ErrorResult& aRv) {
bool isShared;
JS::Rooted<JSObject*> viewedBufferX(
aCx, JS_GetArrayBufferViewBuffer(aCx, aX, &isShared));
if (!viewedBufferX) {
aRv.StealExceptionFromJSContext(aCx);
return false;
}
JS::Rooted<JSObject*> viewedBufferY(
aCx, JS_GetArrayBufferViewBuffer(aCx, aY, &isShared));
if (!viewedBufferY) {
aRv.StealExceptionFromJSContext(aCx);
return false;
}
return viewedBufferX == viewedBufferY;
}
void ReadableStream::EnqueueNative(JSContext* aCx, JS::Handle<JS::Value> aChunk,
ErrorResult& aRv) {
MOZ_ASSERT(mController->GetAlgorithms()->IsNative());
// Step 1: If stream.[[controller]] implements
// ReadableStreamDefaultController,
if (mController->IsDefault()) {
// Step 1.1: Perform !
// ReadableStreamDefaultControllerEnqueue(stream.[[controller]], chunk).
RefPtr<ReadableStreamDefaultController> controller =
mController->AsDefault();
ReadableStreamDefaultControllerEnqueue(aCx, controller, aChunk, aRv);
return;
}
// Step 2.1: Assert: stream.[[controller]] implements
// ReadableByteStreamController.
MOZ_ASSERT(mController->IsByte());
RefPtr<ReadableByteStreamController> controller = mController->AsByte();
// Step 2.2: Assert: chunk is an ArrayBufferView.
MOZ_ASSERT(aChunk.isObject() &&
JS_IsArrayBufferViewObject(&aChunk.toObject()));
JS::Rooted<JSObject*> chunk(aCx, &aChunk.toObject());
// Step 3: Let byobView be the current BYOB request view for stream.
JS::Rooted<JSObject*> byobView(aCx);
CurrentBYOBRequestView(aCx, *controller, &byobView, aRv);
if (aRv.Failed()) {
return;
}
// Step 4: If byobView is non-null, and chunk.[[ViewedArrayBuffer]] is
// byobView.[[ViewedArrayBuffer]], then:
if (byobView && HasSameBufferView(aCx, chunk, byobView, aRv)) {
// Step 4.1: Assert: chunk.[[ByteOffset]] is byobView.[[ByteOffset]].
MOZ_ASSERT(JS_GetArrayBufferViewByteOffset(chunk) ==
JS_GetArrayBufferViewByteOffset(byobView));
// Step 4.2: Assert: chunk.[[ByteLength]] ≤ byobView.[[ByteLength]].
MOZ_ASSERT(JS_GetArrayBufferViewByteLength(chunk) <=
JS_GetArrayBufferViewByteLength(byobView));
// Step 4.3: Perform ?
// ReadableByteStreamControllerRespond(stream.[[controller]],
// chunk.[[ByteLength]]).
ReadableByteStreamControllerRespond(
aCx, controller, JS_GetArrayBufferViewByteLength(chunk), aRv);
return;
}
if (aRv.Failed()) {
return;
}
// Step 5: Otherwise, perform ?
// ReadableByteStreamControllerEnqueue(stream.[[controller]], chunk).
ReadableByteStreamControllerEnqueue(aCx, controller, chunk, aRv);
}
void ReadableStream::GetCurrentBYOBRequestView(
JSContext* aCx, JS::MutableHandle<JSObject*> aView, ErrorResult& aRv) {
aView.set(nullptr);
// Step 1: Assert: stream.[[controller]] implements
// ReadableByteStreamController.
MOZ_ASSERT(mController->IsByte());
// Step 2: Let byobRequest be !
// ReadableByteStreamControllerGetBYOBRequest(stream.[[controller]]).
RefPtr<ReadableStreamBYOBRequest> byobRequest =
mController->AsByte()->GetByobRequest(aCx, aRv);
// Step 3: If byobRequest is null, then return null.
if (!byobRequest || aRv.Failed()) {
return;
}
// Step 4: Return byobRequest.[[view]].
byobRequest->GetView(aCx, aView);
}
// To get a reader for a ReadableStream stream, return ?
// AcquireReadableStreamDefaultReader(stream). The result will be a
// ReadableStreamDefaultReader.
already_AddRefed<mozilla::dom::ReadableStreamDefaultReader>
ReadableStream::GetReader(ErrorResult& aRv) {
return AcquireReadableStreamDefaultReader(this, aRv);
}
} // namespace mozilla::dom