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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_UnderlyingSinkCallbackHelpers_h
#define mozilla_dom_UnderlyingSinkCallbackHelpers_h
#include "mozilla/Maybe.h"
#include "mozilla/Buffer.h"
#include "mozilla/HoldDropJSObjects.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/UnderlyingSinkBinding.h"
#include "nsCycleCollectionParticipant.h"
#include "nsISupports.h"
#include "nsISupportsImpl.h"
#include "nsIAsyncOutputStream.h"
/*
* See the comment in UnderlyingSourceCallbackHelpers.h!
*
* A native implementation of these callbacks is however currently not required.
*/
namespace mozilla::dom {
class WritableStreamDefaultController;
class UnderlyingSinkAlgorithmsBase : public nsISupports {
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_CLASS(UnderlyingSinkAlgorithmsBase)
MOZ_CAN_RUN_SCRIPT virtual void StartCallback(
JSContext* aCx, WritableStreamDefaultController& aController,
JS::MutableHandle<JS::Value> aRetVal, ErrorResult& aRv) = 0;
MOZ_CAN_RUN_SCRIPT virtual already_AddRefed<Promise> WriteCallback(
JSContext* aCx, JS::Handle<JS::Value> aChunk,
WritableStreamDefaultController& aController, ErrorResult& aRv) = 0;
MOZ_CAN_RUN_SCRIPT virtual already_AddRefed<Promise> CloseCallback(
JSContext* aCx, ErrorResult& aRv) = 0;
MOZ_CAN_RUN_SCRIPT virtual already_AddRefed<Promise> AbortCallback(
JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
ErrorResult& aRv) = 0;
// Implement this when you need to release underlying resources immediately
// from closed/errored(aborted) streams, without waiting for GC.
virtual void ReleaseObjects() {}
protected:
virtual ~UnderlyingSinkAlgorithmsBase() = default;
};
// https://streams.spec.whatwg.org/#set-up-writable-stream-default-controller-from-underlying-sink
class UnderlyingSinkAlgorithms final : public UnderlyingSinkAlgorithmsBase {
public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(
UnderlyingSinkAlgorithms, UnderlyingSinkAlgorithmsBase)
UnderlyingSinkAlgorithms(nsIGlobalObject* aGlobal,
JS::Handle<JSObject*> aUnderlyingSink,
UnderlyingSink& aUnderlyingSinkDict)
: mGlobal(aGlobal), mUnderlyingSink(aUnderlyingSink) {
// Step 6. (implicit Step 2.)
if (aUnderlyingSinkDict.mStart.WasPassed()) {
mStartCallback = aUnderlyingSinkDict.mStart.Value();
}
// Step 7. (implicit Step 3.)
if (aUnderlyingSinkDict.mWrite.WasPassed()) {
mWriteCallback = aUnderlyingSinkDict.mWrite.Value();
}
// Step 8. (implicit Step 4.)
if (aUnderlyingSinkDict.mClose.WasPassed()) {
mCloseCallback = aUnderlyingSinkDict.mClose.Value();
}
// Step 9. (implicit Step 5.)
if (aUnderlyingSinkDict.mAbort.WasPassed()) {
mAbortCallback = aUnderlyingSinkDict.mAbort.Value();
}
mozilla::HoldJSObjects(this);
};
MOZ_CAN_RUN_SCRIPT void StartCallback(
JSContext* aCx, WritableStreamDefaultController& aController,
JS::MutableHandle<JS::Value> aRetVal, ErrorResult& aRv) override;
MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> WriteCallback(
JSContext* aCx, JS::Handle<JS::Value> aChunk,
WritableStreamDefaultController& aController, ErrorResult& aRv) override;
MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> CloseCallback(
JSContext* aCx, ErrorResult& aRv) override;
MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> AbortCallback(
JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
ErrorResult& aRv) override;
protected:
~UnderlyingSinkAlgorithms() override { mozilla::DropJSObjects(this); }
private:
// Virtually const, but are cycle collected
nsCOMPtr<nsIGlobalObject> mGlobal;
JS::Heap<JSObject*> mUnderlyingSink;
MOZ_KNOWN_LIVE RefPtr<UnderlyingSinkStartCallback> mStartCallback;
MOZ_KNOWN_LIVE RefPtr<UnderlyingSinkWriteCallback> mWriteCallback;
MOZ_KNOWN_LIVE RefPtr<UnderlyingSinkCloseCallback> mCloseCallback;
MOZ_KNOWN_LIVE RefPtr<UnderlyingSinkAbortCallback> mAbortCallback;
};
// https://streams.spec.whatwg.org/#writablestream-set-up
// Wrappers defined by the "Set up" methods in the spec.
// (closeAlgorithmWrapper, abortAlgorithmWrapper)
// This helps you just return nullptr when 1) the algorithm is synchronous, or
// 2) an error occurred, as this wrapper will return a resolved or rejected
// promise respectively.
// Note that StartCallback is only for JS consumers to access the
// controller, and thus is no-op here since native consumers can call
// `ErrorNative()` etc. without direct controller access.
class UnderlyingSinkAlgorithmsWrapper : public UnderlyingSinkAlgorithmsBase {
public:
void StartCallback(JSContext* aCx,
WritableStreamDefaultController& aController,
JS::MutableHandle<JS::Value> aRetVal,
ErrorResult& aRv) final {
// Step 1: Let startAlgorithm be an algorithm that returns undefined.
aRetVal.setUndefined();
}
MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> CloseCallback(
JSContext* aCx, ErrorResult& aRv) final;
MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> AbortCallback(
JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
ErrorResult& aRv) final;
virtual already_AddRefed<Promise> CloseCallbackImpl(JSContext* aCx,
ErrorResult& aRv) {
// (closeAlgorithm is optional, give null by default)
return nullptr;
}
virtual already_AddRefed<Promise> AbortCallbackImpl(
JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
ErrorResult& aRv) {
// (abortAlgorithm is optional, give null by default)
return nullptr;
}
};
class WritableStreamToOutput final : public UnderlyingSinkAlgorithmsWrapper,
public nsIOutputStreamCallback {
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_NSIOUTPUTSTREAMCALLBACK
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(WritableStreamToOutput,
UnderlyingSinkAlgorithmsBase)
WritableStreamToOutput(nsIGlobalObject* aParent,
nsIAsyncOutputStream* aOutput)
: mWritten(0), mParent(aParent), mOutput(aOutput) {}
// Streams algorithms
already_AddRefed<Promise> WriteCallback(
JSContext* aCx, JS::Handle<JS::Value> aChunk,
WritableStreamDefaultController& aController, ErrorResult& aRv) override;
// No CloseCallbackImpl() since ReleaseObjects() will call Close()
already_AddRefed<Promise> AbortCallbackImpl(
JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
ErrorResult& aRv) override;
void ReleaseObjects() override;
private:
~WritableStreamToOutput() override = default;
void ClearData() {
mData = Nothing();
mPromise = nullptr;
mWritten = 0;
}
uint32_t mWritten;
nsCOMPtr<nsIGlobalObject> mParent;
nsCOMPtr<nsIAsyncOutputStream> mOutput;
RefPtr<Promise> mPromise; // Resolved when entirely written
Maybe<Buffer<uint8_t>> mData;
};
} // namespace mozilla::dom
#endif
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