gecko-dev/dom/streams/ReadableByteStreamController.h

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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/. */
#ifndef mozilla_dom_ReadableByteStreamController_h
#define mozilla_dom_ReadableByteStreamController_h
#include <cstddef>
#include "js/RootingAPI.h"
#include "js/TypeDecls.h"
#include "mozilla/Attributes.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "mozilla/dom/QueuingStrategyBinding.h"
#include "mozilla/dom/QueueWithSizes.h"
#include "mozilla/dom/ReadableStream.h"
#include "mozilla/dom/ReadRequest.h"
#include "mozilla/dom/ReadableStreamBYOBRequest.h"
#include "mozilla/dom/ReadableStreamController.h"
#include "mozilla/dom/TypedArray.h"
#include "mozilla/dom/UnderlyingSourceCallbackHelpers.h"
#include "nsCycleCollectionParticipant.h"
#include "nsWrapperCache.h"
#include "mozilla/dom/Nullable.h"
#include "nsTArray.h"
#include "nsISupportsImpl.h"
namespace mozilla::dom {
enum ReaderType { Default, BYOB };
struct PullIntoDescriptor;
struct ReadableByteStreamQueueEntry;
struct ReadIntoRequest;
class ReadableByteStreamController final : public ReadableStreamController,
public nsWrapperCache {
public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(
ReadableByteStreamController, ReadableStreamController)
public:
explicit ReadableByteStreamController(nsIGlobalObject* aGlobal);
protected:
~ReadableByteStreamController();
public:
bool IsDefault() override { return false; }
bool IsByte() override { return true; }
ReadableStreamDefaultController* AsDefault() override { return nullptr; }
ReadableByteStreamController* AsByte() override { return this; }
JSObject* WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) override;
already_AddRefed<ReadableStreamBYOBRequest> GetByobRequest(JSContext* aCx);
Nullable<double> GetDesiredSize() const;
void Close(JSContext* aCx, ErrorResult& aRv);
void Enqueue(JSContext* aCx, const ArrayBufferView& aChunk, ErrorResult& aRv);
void Error(JSContext* aCx, JS::Handle<JS::Value> aErrorValue,
ErrorResult& aRv);
virtual already_AddRefed<Promise> CancelSteps(JSContext* aCx,
JS::Handle<JS::Value> aReason,
ErrorResult& aRv) override;
virtual void PullSteps(JSContext* aCx, ReadRequest* aReadRequest,
ErrorResult& aRv) override;
// Internal Slot Accessors
Maybe<uint64_t> AutoAllocateChunkSize() { return mAutoAllocateChunkSize; }
void SetAutoAllocateChunkSize(Maybe<uint64_t>& aSize) {
mAutoAllocateChunkSize = aSize;
}
ReadableStreamBYOBRequest* GetByobRequest() const { return mByobRequest; }
void SetByobRequest(ReadableStreamBYOBRequest* aByobRequest) {
mByobRequest = aByobRequest;
}
LinkedList<RefPtr<PullIntoDescriptor>>& PendingPullIntos() {
return mPendingPullIntos;
}
void ClearPendingPullIntos();
ReadableStream* Stream() const { return mStream; }
double QueueTotalSize() const { return mQueueTotalSize; }
void SetQueueTotalSize(double aQueueTotalSize) {
mQueueTotalSize = aQueueTotalSize;
}
void AddToQueueTotalSize(double aLength) { mQueueTotalSize += aLength; }
double StrategyHWM() const { return mStrategyHWM; }
void SetStrategyHWM(double aStrategyHWM) { mStrategyHWM = aStrategyHWM; }
bool CloseRequested() const { return mCloseRequested; }
void SetCloseRequested(bool aCloseRequested) {
mCloseRequested = aCloseRequested;
}
UnderlyingSourceCancelCallbackHelper* GetCancelAlgorithm() const {
return mCancelAlgorithm;
}
void SetCancelAlgorithm(
UnderlyingSourceCancelCallbackHelper* aCancelAlgorithm) {
mCancelAlgorithm = aCancelAlgorithm;
}
UnderlyingSourcePullCallbackHelper* GetPullAlgorithm() const {
return mPullAlgorithm;
}
void SetPullAlgorithm(UnderlyingSourcePullCallbackHelper* aPullAlgorithm) {
mPullAlgorithm = aPullAlgorithm;
}
LinkedList<RefPtr<ReadableByteStreamQueueEntry>>& Queue() { return mQueue; }
void ClearQueue();
bool Started() const { return mStarted; }
void SetStarted(bool aStarted) { mStarted = aStarted; }
bool Pulling() const { return mPulling; }
void SetPulling(bool aPulling) { mPulling = aPulling; }
bool PullAgain() const { return mPullAgain; }
void SetPullAgain(bool aPullAgain) { mPullAgain = aPullAgain; }
private:
// A boolean flag indicating whether the stream has been closed by its
// underlying byte source, but still has chunks in its internal queue that
// have not yet been read
bool mCloseRequested = false;
// A boolean flag set to true if the streams mechanisms requested a call
// to the underlying byte source's pull algorithm to pull more data, but the
// pull could not yet be done since a previous call is still executing
bool mPullAgain = false;
// A boolean flag indicating whether the underlying byte source has finished
// starting
bool mStarted = false;
// A boolean flag set to true while the underlying byte source's pull
// algorithm is executing and the returned promise has not yet fulfilled,
// used to prevent reentrant calls
bool mPulling = false;
// A positive integer, when the automatic buffer allocation feature is
// enabled. In that case, this value specifies the size of buffer to allocate.
// It is undefined otherwise.
Maybe<uint64_t> mAutoAllocateChunkSize;
// A ReadableStreamBYOBRequest instance representing the current BYOB pull
// request, or null if there are no pending requests
RefPtr<ReadableStreamBYOBRequest> mByobRequest;
// A promise-returning algorithm, taking one argument (the cancel reason),
// which communicates a requested cancelation to the underlying byte source
RefPtr<UnderlyingSourceCancelCallbackHelper> mCancelAlgorithm;
// A promise-returning algorithm that pulls data from the underlying byte
// source
RefPtr<UnderlyingSourcePullCallbackHelper> mPullAlgorithm;
// A list of pull-into descriptors
LinkedList<RefPtr<PullIntoDescriptor>> mPendingPullIntos;
// A list of readable byte stream queue entries representing the streams
// internal queue of chunks
//
// This is theoretically supposed to be a QueueWithSizes, but it is
// mostly not actually manipulated or used like QueueWithSizes, so instead we
// use a LinkedList.
LinkedList<RefPtr<ReadableByteStreamQueueEntry>> mQueue;
// The total size, in bytes, of all the chunks stored in [[queue]] (see §8.1
// Queue-with-sizes)
double mQueueTotalSize = 0.0;
// A number supplied to the constructor as part of the streams queuing
// strategy, indicating the point at which the stream will apply backpressure
// to its underlying byte source
double mStrategyHWM = 0.0;
RefPtr<ReadableStream> mStream;
};
// https://streams.spec.whatwg.org/#readable-byte-stream-queue-entry
// Important: These list elements need to be traced by the owning structure.
struct ReadableByteStreamQueueEntry
: LinkedListElement<RefPtr<ReadableByteStreamQueueEntry>> {
NS_INLINE_DECL_REFCOUNTING(mozilla::dom::ReadableByteStreamQueueEntry)
friend class ReadableByteStreamController::cycleCollection;
ReadableByteStreamQueueEntry(JS::Handle<JSObject*> aBuffer,
size_t aByteOffset, size_t aByteLength)
: LinkedListElement<RefPtr<ReadableByteStreamQueueEntry>>(),
mBuffer(aBuffer),
mByteOffset(aByteOffset),
mByteLength(aByteLength) {}
JSObject* Buffer() const { return mBuffer; }
void SetBuffer(JS::Handle<JSObject*> aBuffer) { mBuffer = aBuffer; }
size_t ByteOffset() const { return mByteOffset; }
void SetByteOffset(size_t aByteOffset) { mByteOffset = aByteOffset; }
size_t ByteLength() const { return mByteLength; }
void SetByteLength(size_t aByteLength) { mByteLength = aByteLength; }
void ClearBuffer() { mBuffer = nullptr; }
private:
// An ArrayBuffer, which will be a transferred version of the one originally
// supplied by the underlying byte source.
//
// This is traced by the list owner (see ReadableByteStreamController's
// tracing code).
JS::Heap<JSObject*> mBuffer;
// A nonnegative integer number giving the byte offset derived from the view
// originally supplied by the underlying byte source
size_t mByteOffset = 0;
// A nonnegative integer number giving the byte length derived from the view
// originally supplied by the underlying byte source
size_t mByteLength = 0;
~ReadableByteStreamQueueEntry() = default;
};
// Important: These list elments need to be traced by the owning structure.
struct PullIntoDescriptor final
: LinkedListElement<RefPtr<PullIntoDescriptor>> {
NS_INLINE_DECL_REFCOUNTING(mozilla::dom::PullIntoDescriptor)
enum Constructor {
DataView,
#define DEFINE_TYPED_CONSTRUCTOR_ENUM_NAMES(ExternalT, NativeT, Name) Name,
JS_FOR_EACH_TYPED_ARRAY(DEFINE_TYPED_CONSTRUCTOR_ENUM_NAMES)
#undef DEFINE_TYPED_CONSTRUCTOR_ENUM_NAMES
};
static Constructor constructorFromScalar(JS::Scalar::Type type) {
switch (type) {
#define REMAP_PULL_INTO_DESCRIPTOR_TYPE(ExternalT, NativeT, Name) \
case JS::Scalar::Name: \
return Constructor::Name;
JS_FOR_EACH_TYPED_ARRAY(REMAP_PULL_INTO_DESCRIPTOR_TYPE)
#undef REMAP
case JS::Scalar::Int64:
case JS::Scalar::Simd128:
case JS::Scalar::MaxTypedArrayViewType:
break;
}
MOZ_CRASH("Unexpected Scalar::Type");
}
friend class ReadableByteStreamController::cycleCollection;
PullIntoDescriptor(JS::Handle<JSObject*> aBuffer, uint64_t aBufferByteLength,
uint64_t aByteOffset, uint64_t aByteLength,
uint64_t aBytesFilled, uint64_t aElementSize,
Constructor aViewConstructor, ReaderType aReaderType)
: LinkedListElement<RefPtr<PullIntoDescriptor>>(),
mBuffer(aBuffer),
mBufferByteLength(aBufferByteLength),
mByteOffset(aByteOffset),
mByteLength(aByteLength),
mBytesFilled(aBytesFilled),
mElementSize(aElementSize),
mViewConstructor(aViewConstructor),
mReaderType(aReaderType) {}
JSObject* Buffer() const { return mBuffer; }
void SetBuffer(JS::Handle<JSObject*> aBuffer) { mBuffer = aBuffer; }
uint64_t BufferByteLength() const { return mBufferByteLength; }
void SetBufferByteLength(const uint64_t aBufferByteLength) {
mBufferByteLength = aBufferByteLength;
}
uint64_t ByteOffset() const { return mByteOffset; }
void SetByteOffset(const uint64_t aByteOffset) { mByteOffset = aByteOffset; }
uint64_t ByteLength() const { return mByteLength; }
void SetByteLength(const uint64_t aByteLength) { mByteLength = aByteLength; }
uint64_t BytesFilled() const { return mBytesFilled; }
void SetBytesFilled(const uint64_t aBytesFilled) {
mBytesFilled = aBytesFilled;
}
uint64_t ElementSize() const { return mElementSize; }
void SetElementSize(const uint64_t aElementSize) {
mElementSize = aElementSize;
}
Constructor ViewConstructor() const { return mViewConstructor; }
// Note: Named GetReaderType to avoid name conflict with type.
ReaderType GetReaderType() const { return mReaderType; }
void SetReaderType(const ReaderType aReaderType) {
mReaderType = aReaderType;
}
void ClearBuffer() { mBuffer = nullptr; }
private:
// This is traced by the list owner (see ReadableByteStreamController's
// tracing code).
JS::Heap<JSObject*> mBuffer;
uint64_t mBufferByteLength = 0;
uint64_t mByteOffset = 0;
uint64_t mByteLength = 0;
uint64_t mBytesFilled = 0;
uint64_t mElementSize = 0;
Constructor mViewConstructor;
ReaderType mReaderType;
~PullIntoDescriptor() = default;
};
extern void ReadableByteStreamControllerRespond(
JSContext* aCx, ReadableByteStreamController* aController,
uint64_t aBytesWritten, ErrorResult& aRv);
extern void ReadableByteStreamControllerRespondInternal(
JSContext* aCx, ReadableByteStreamController* aController,
uint64_t aBytesWritten, ErrorResult& aRv);
extern void ReadableByteStreamControllerRespondWithNewView(
JSContext* aCx, ReadableByteStreamController* aController,
JS::Handle<JSObject*> aView, ErrorResult& aRv);
extern void ReadableByteStreamControllerPullInto(
JSContext* aCx, ReadableByteStreamController* aController,
JS::HandleObject aView, ReadIntoRequest* aReadIntoRequest,
ErrorResult& aRv);
} // namespace mozilla::dom
#endif