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			245 lines
		
	
	
	
		
			8.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			245 lines
		
	
	
	
		
			8.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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| /* vim:set ts=2 sw=2 sts=2 et cindent: */
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| /* This Source Code Form is subject to the terms of the Mozilla Public
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|  * License, v. 2.0. If a copy of the MPL was not distributed with this
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|  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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| 
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| #include "mozilla/dom/TextDecoderStream.h"
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| 
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| #include "nsContentUtils.h"
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| #include "nsIGlobalObject.h"
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| #include "mozilla/Encoding.h"
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| #include "mozilla/dom/Promise.h"
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| #include "mozilla/dom/TextDecoderStreamBinding.h"
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| #include "mozilla/dom/TransformerCallbackHelpers.h"
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| #include "mozilla/dom/TransformStream.h"
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| #include "mozilla/dom/UnionTypes.h"
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| 
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| namespace mozilla::dom {
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| 
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| NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(TextDecoderStream, mGlobal, mStream)
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| NS_IMPL_CYCLE_COLLECTING_ADDREF(TextDecoderStream)
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| NS_IMPL_CYCLE_COLLECTING_RELEASE(TextDecoderStream)
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| NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TextDecoderStream)
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|   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
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|   NS_INTERFACE_MAP_ENTRY(nsISupports)
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| NS_INTERFACE_MAP_END
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| 
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| TextDecoderStream::TextDecoderStream(nsISupports* aGlobal,
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|                                      const Encoding& aEncoding, bool aFatal,
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|                                      bool aIgnoreBOM, TransformStream& aStream)
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|     : mGlobal(aGlobal), mStream(&aStream) {
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|   mFatal = aFatal;
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|   mIgnoreBOM = aIgnoreBOM;
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|   aEncoding.Name(mEncoding);
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|   if (aIgnoreBOM) {
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|     mDecoder = aEncoding.NewDecoderWithoutBOMHandling();
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|   } else {
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|     mDecoder = aEncoding.NewDecoderWithBOMRemoval();
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|   }
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| }
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| 
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| TextDecoderStream::~TextDecoderStream() = default;
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| 
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| JSObject* TextDecoderStream::WrapObject(JSContext* aCx,
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|                                         JS::Handle<JSObject*> aGivenProto) {
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|   return TextDecoderStream_Binding::Wrap(aCx, this, aGivenProto);
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| }
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| 
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| // TODO: This function should probably be generated by bindings layer. (Bug
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| // 1784266)
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| // TODO: This does not allow shared array buffers, just as the non-stream
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| // TextDecoder/Encoder don't. (Bug 1561594)
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| static Span<const uint8_t> ExtractSpanFromBufferSource(
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|     JSContext* aCx, JS::Handle<JS::Value> aBufferSource, ErrorResult& aRv) {
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|   if (!aBufferSource.isObject()) {
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|     aRv.ThrowTypeError("Input is not an ArrayBuffer nor an ArrayBufferView");
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|     return Span<const uint8_t>();
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|   }
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| 
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|   bool tryNext;
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|   RootedUnion<OwningArrayBufferViewOrArrayBuffer> bufferSource(aCx);
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|   if (bufferSource.TrySetToArrayBufferView(aCx, aBufferSource, tryNext,
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|                                            false) &&
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|       !tryNext) {
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|     ArrayBufferView& view = bufferSource.GetAsArrayBufferView();
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|     view.ComputeState();
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|     return Span(view.Data(), view.Length());
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|   }
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|   if (!tryNext) {
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|     aRv.MightThrowJSException();
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|     aRv.StealExceptionFromJSContext(aCx);
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|     return Span<const uint8_t>();
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|   }
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| 
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|   if (bufferSource.TrySetToArrayBuffer(aCx, aBufferSource, tryNext, false) &&
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|       !tryNext) {
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|     ArrayBuffer& buffer = bufferSource.GetAsArrayBuffer();
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|     buffer.ComputeState();
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|     return Span(buffer.Data(), buffer.Length());
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|   }
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|   if (!tryNext) {
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|     aRv.MightThrowJSException();
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|     aRv.StealExceptionFromJSContext(aCx);
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|     return Span<const uint8_t>();
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|   }
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| 
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|   aRv.ThrowTypeError("Input is not an ArrayBuffer nor an ArrayBufferView");
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|   return Span<const uint8_t>();
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| }
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| 
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| class TextDecoderStreamAlgorithms : public TransformerAlgorithmsWrapper {
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|   NS_DECL_ISUPPORTS_INHERITED
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|   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(TextDecoderStreamAlgorithms,
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|                                            TransformerAlgorithmsBase)
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| 
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|   void SetDecoderStream(TextDecoderStream& aStream) {
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|     mDecoderStream = &aStream;
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|   }
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| 
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|   // The common part of decode-and-enqueue and flush-and-enqueue.
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|   // Note that the most of the decoding algorithm is implemented in
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|   // mozilla::Decoder, and this is mainly about calling it properly.
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|   // https://encoding.spec.whatwg.org/#decode-and-enqueue-a-chunk
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|   MOZ_CAN_RUN_SCRIPT void DecodeSpanAndEnqueue(
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|       JSContext* aCx, Span<const uint8_t> aInput, bool aFlush,
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|       TransformStreamDefaultController& aController, ErrorResult& aRv) {
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|     CheckedInt<nsAString::size_type> needed =
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|         mDecoderStream->Decoder()->MaxUTF16BufferLength(aInput.Length());
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|     if (!needed.isValid()) {
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|       aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
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|       return;
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|     }
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| 
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|     nsString outDecodedString;
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|     auto output = outDecodedString.GetMutableData(needed.value(), fallible);
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|     if (!output) {
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|       aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
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|       return;
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|     }
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| 
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|     mDecoderStream->DecodeNative(aInput, !aFlush, outDecodedString, aRv);
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|     if (aRv.Failed()) {
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|       return;
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|     }
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| 
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|     if (outDecodedString.Length()) {
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|       // Step 4.2. If outputChunk is non-empty, then enqueue outputChunk in
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|       // decoder’s transform.
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|       JS::Rooted<JS::Value> outputChunk(aCx);
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|       if (!xpc::NonVoidStringToJsval(aCx, outDecodedString, &outputChunk)) {
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|         JS_ClearPendingException(aCx);
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|         aRv.Throw(NS_ERROR_UNEXPECTED);
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|         return;
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|       }
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|       aController.Enqueue(aCx, outputChunk, aRv);
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|     }
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|   }
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| 
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|   // https://encoding.spec.whatwg.org/#dom-textdecoderstream
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|   MOZ_CAN_RUN_SCRIPT void TransformCallbackImpl(
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|       JS::Handle<JS::Value> aChunk,
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|       TransformStreamDefaultController& aController,
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|       ErrorResult& aRv) override {
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|     // Step 7. Let transformAlgorithm be an algorithm which takes a chunk
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|     // argument and runs the decode and enqueue a chunk algorithm with this and
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|     // chunk.
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| 
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|     // https://encoding.spec.whatwg.org/#decode-and-enqueue-a-chunk
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| 
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|     AutoJSAPI jsapi;
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|     if (!jsapi.Init(aController.GetParentObject())) {
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|       aRv.ThrowUnknownError("Internal error");
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|       return;
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|     }
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|     JSContext* cx = jsapi.cx();
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| 
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|     // Step 1. Let bufferSource be the result of converting chunk to an
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|     // [AllowShared] BufferSource.
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|     // (But here we get a mozilla::Span instead)
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|     Span<const uint8_t> input = ExtractSpanFromBufferSource(cx, aChunk, aRv);
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|     if (aRv.Failed()) {
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|       return;
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|     }
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| 
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|     DecodeSpanAndEnqueue(cx, input, false, aController, aRv);
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|   }
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| 
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|   // https://encoding.spec.whatwg.org/#dom-textdecoderstream
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|   MOZ_CAN_RUN_SCRIPT void FlushCallbackImpl(
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|       TransformStreamDefaultController& aController,
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|       ErrorResult& aRv) override {
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|     // Step 8. Let flushAlgorithm be an algorithm which takes no arguments and
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|     // runs the flush and enqueue algorithm with this.
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| 
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|     AutoJSAPI jsapi;
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|     if (!jsapi.Init(aController.GetParentObject())) {
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|       aRv.ThrowUnknownError("Internal error");
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|       return;
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|     }
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|     JSContext* cx = jsapi.cx();
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| 
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|     // https://encoding.spec.whatwg.org/#flush-and-enqueue
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|     // (The flush and enqueue algorithm is basically a subset of decode and
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|     // enqueue one, so let's reuse it)
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|     DecodeSpanAndEnqueue(cx, Span<const uint8_t>(), true, aController, aRv);
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|   }
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| 
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|  private:
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|   ~TextDecoderStreamAlgorithms() override = default;
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| 
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|   RefPtr<TextDecoderStream> mDecoderStream;
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| };
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| 
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| NS_IMPL_CYCLE_COLLECTION_INHERITED(TextDecoderStreamAlgorithms,
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|                                    TransformerAlgorithmsBase, mDecoderStream)
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| NS_IMPL_ADDREF_INHERITED(TextDecoderStreamAlgorithms, TransformerAlgorithmsBase)
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| NS_IMPL_RELEASE_INHERITED(TextDecoderStreamAlgorithms,
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|                           TransformerAlgorithmsBase)
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| NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TextDecoderStreamAlgorithms)
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| NS_INTERFACE_MAP_END_INHERITING(TransformerAlgorithmsBase)
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| 
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| // https://encoding.spec.whatwg.org/#dom-textdecoderstream
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| already_AddRefed<TextDecoderStream> TextDecoderStream::Constructor(
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|     const GlobalObject& aGlobal, const nsAString& aLabel,
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|     const TextDecoderOptions& aOptions, ErrorResult& aRv) {
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|   // Step 1. Let encoding be the result of getting an encoding from label.
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|   const Encoding* encoding = Encoding::ForLabelNoReplacement(aLabel);
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| 
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|   // Step 2. If encoding is failure or replacement, then throw a RangeError
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|   if (!encoding) {
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|     NS_ConvertUTF16toUTF8 label(aLabel);
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|     label.Trim(" \t\n\f\r");
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|     aRv.ThrowRangeError<MSG_ENCODING_NOT_SUPPORTED>(label);
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|     return nullptr;
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|   }
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| 
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|   // Step 3-6. (Done in the constructor)
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| 
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|   // Step 7-8.
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|   auto algorithms = MakeRefPtr<TextDecoderStreamAlgorithms>();
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| 
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|   // Step 9-10.
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|   RefPtr<TransformStream> transformStream =
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|       TransformStream::CreateGeneric(aGlobal, *algorithms, aRv);
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|   if (aRv.Failed()) {
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|     return nullptr;
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|   }
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| 
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|   // Step 11. (Done in the constructor)
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|   auto decoderStream = MakeRefPtr<TextDecoderStream>(
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|       aGlobal.GetAsSupports(), *encoding, aOptions.mFatal, aOptions.mIgnoreBOM,
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|       *transformStream);
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|   algorithms->SetDecoderStream(*decoderStream);
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|   return decoderStream.forget();
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| }
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| 
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| ReadableStream* TextDecoderStream::Readable() const {
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|   return mStream->Readable();
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| }
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| 
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| WritableStream* TextDecoderStream::Writable() const {
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|   return mStream->Writable();
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| }
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| 
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| }  // namespace mozilla::dom
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