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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/TextDecoderStream.h"
#include "mozilla/Encoding.h"
#include "mozilla/dom/BufferSourceBinding.h"
#include "mozilla/dom/Promise.h"
#include "mozilla/dom/TextDecoderStreamBinding.h"
#include "mozilla/dom/TransformStream.h"
#include "mozilla/dom/TransformerCallbackHelpers.h"
#include "mozilla/dom/UnionTypes.h"
#include "nsContentUtils.h"
#include "nsIGlobalObject.h"
namespace mozilla::dom {
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(TextDecoderStream, mGlobal, mStream)
NS_IMPL_CYCLE_COLLECTING_ADDREF(TextDecoderStream)
NS_IMPL_CYCLE_COLLECTING_RELEASE(TextDecoderStream)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TextDecoderStream)
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
TextDecoderStream::TextDecoderStream(nsISupports* aGlobal,
const Encoding& aEncoding, bool aFatal,
bool aIgnoreBOM, TransformStream& aStream)
: mGlobal(aGlobal), mStream(&aStream) {
mFatal = aFatal;
mIgnoreBOM = aIgnoreBOM;
aEncoding.Name(mEncoding);
if (aIgnoreBOM) {
mDecoder = aEncoding.NewDecoderWithoutBOMHandling();
} else {
mDecoder = aEncoding.NewDecoderWithBOMRemoval();
}
}
TextDecoderStream::~TextDecoderStream() = default;
JSObject* TextDecoderStream::WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return TextDecoderStream_Binding::Wrap(aCx, this, aGivenProto);
}
class TextDecoderStreamAlgorithms : public TransformerAlgorithmsWrapper {
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(TextDecoderStreamAlgorithms,
TransformerAlgorithmsBase)
void SetDecoderStream(TextDecoderStream& aStream) {
mDecoderStream = &aStream;
}
// The common part of decode-and-enqueue and flush-and-enqueue.
// Note that the most of the decoding algorithm is implemented in
// mozilla::Decoder, and this is mainly about calling it properly.
// https://encoding.spec.whatwg.org/#decode-and-enqueue-a-chunk
// TODO: This does not allow shared array buffers, just as the non-stream
// TextDecoder/Encoder don't. (Bug 1561594)
MOZ_CAN_RUN_SCRIPT void DecodeBufferSourceAndEnqueue(
JSContext* aCx, OwningBufferSource* aInput, bool aFlush,
TransformStreamDefaultController& aController, ErrorResult& aRv) {
nsString outDecodedString;
if (aInput) {
ProcessTypedArrays(*aInput, [&](const Span<const uint8_t>& aData,
JS::AutoCheckCannotGC&&) {
mDecoderStream->DecodeNative(aData, !aFlush, outDecodedString, aRv);
});
} else {
mDecoderStream->DecodeNative(Span<const uint8_t>(), !aFlush,
outDecodedString, aRv);
}
if (aRv.Failed()) {
return;
}
if (outDecodedString.Length()) {
// Step 4.2. If outputChunk is non-empty, then enqueue outputChunk in
// decoder’s transform.
JS::Rooted<JS::Value> outputChunk(aCx);
if (!ToJSValue(aCx, outDecodedString, &outputChunk)) {
JS_ClearPendingException(aCx);
aRv.Throw(NS_ERROR_UNEXPECTED);
return;
}
aController.Enqueue(aCx, outputChunk, aRv);
}
}
// https://encoding.spec.whatwg.org/#dom-textdecoderstream
MOZ_CAN_RUN_SCRIPT void TransformCallbackImpl(
JS::Handle<JS::Value> aChunk,
TransformStreamDefaultController& aController,
ErrorResult& aRv) override {
// Step 7. Let transformAlgorithm be an algorithm which takes a chunk
// argument and runs the decode and enqueue a chunk algorithm with this and
// chunk.
// https://encoding.spec.whatwg.org/#decode-and-enqueue-a-chunk
AutoJSAPI jsapi;
if (!jsapi.Init(aController.GetParentObject())) {
aRv.ThrowUnknownError("Internal error");
return;
}
JSContext* cx = jsapi.cx();
// Step 1. Let bufferSource be the result of converting chunk to an
// [AllowShared] BufferSource.
RootedUnion<OwningBufferSource> bufferSource(cx);
if (!bufferSource.Init(cx, aChunk)) {
aRv.MightThrowJSException();
aRv.StealExceptionFromJSContext(cx);
return;
}
DecodeBufferSourceAndEnqueue(cx, &bufferSource, false, aController, aRv);
}
// https://encoding.spec.whatwg.org/#dom-textdecoderstream
MOZ_CAN_RUN_SCRIPT void FlushCallbackImpl(
TransformStreamDefaultController& aController,
ErrorResult& aRv) override {
// Step 8. Let flushAlgorithm be an algorithm which takes no arguments and
// runs the flush and enqueue algorithm with this.
AutoJSAPI jsapi;
if (!jsapi.Init(aController.GetParentObject())) {
aRv.ThrowUnknownError("Internal error");
return;
}
JSContext* cx = jsapi.cx();
// https://encoding.spec.whatwg.org/#flush-and-enqueue
// (The flush and enqueue algorithm is basically a subset of decode and
// enqueue one, so let's reuse it)
DecodeBufferSourceAndEnqueue(cx, nullptr, true, aController, aRv);
}
private:
~TextDecoderStreamAlgorithms() override = default;
RefPtr<TextDecoderStream> mDecoderStream;
};
NS_IMPL_CYCLE_COLLECTION_INHERITED(TextDecoderStreamAlgorithms,
TransformerAlgorithmsBase, mDecoderStream)
NS_IMPL_ADDREF_INHERITED(TextDecoderStreamAlgorithms, TransformerAlgorithmsBase)
NS_IMPL_RELEASE_INHERITED(TextDecoderStreamAlgorithms,
TransformerAlgorithmsBase)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TextDecoderStreamAlgorithms)
NS_INTERFACE_MAP_END_INHERITING(TransformerAlgorithmsBase)
// https://encoding.spec.whatwg.org/#dom-textdecoderstream
already_AddRefed<TextDecoderStream> TextDecoderStream::Constructor(
const GlobalObject& aGlobal, const nsAString& aLabel,
const TextDecoderOptions& aOptions, ErrorResult& aRv) {
// Step 1. Let encoding be the result of getting an encoding from label.
const Encoding* encoding = Encoding::ForLabelNoReplacement(aLabel);
// Step 2. If encoding is failure or replacement, then throw a RangeError
if (!encoding) {
NS_ConvertUTF16toUTF8 label(aLabel);
label.Trim(" \t\n\f\r");
aRv.ThrowRangeError<MSG_ENCODING_NOT_SUPPORTED>(label);
return nullptr;
}
// Step 3-6. (Done in the constructor)
// Step 7-8.
auto algorithms = MakeRefPtr<TextDecoderStreamAlgorithms>();
// Step 9-10.
RefPtr<TransformStream> transformStream =
TransformStream::CreateGeneric(aGlobal, *algorithms, aRv);
if (aRv.Failed()) {
return nullptr;
}
// Step 11. (Done in the constructor)
auto decoderStream = MakeRefPtr<TextDecoderStream>(
aGlobal.GetAsSupports(), *encoding, aOptions.mFatal, aOptions.mIgnoreBOM,
*transformStream);
algorithms->SetDecoderStream(*decoderStream);
return decoderStream.forget();
}
ReadableStream* TextDecoderStream::Readable() const {
return mStream->Readable();
}
WritableStream* TextDecoderStream::Writable() const {
return mStream->Writable();
}
} // namespace mozilla::dom
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