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-rw-r--r--dom/encoding/TextDecoderStream.cpp225
1 files changed, 225 insertions, 0 deletions
diff --git a/dom/encoding/TextDecoderStream.cpp b/dom/encoding/TextDecoderStream.cpp
new file mode 100644
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--- /dev/null
+++ b/dom/encoding/TextDecoderStream.cpp
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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 "nsContentUtils.h"
+#include "nsIGlobalObject.h"
+#include "mozilla/Encoding.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/TextDecoderStreamBinding.h"
+#include "mozilla/dom/TransformerCallbackHelpers.h"
+#include "mozilla/dom/TransformStream.h"
+#include "mozilla/dom/UnionTypes.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);
+}
+
+// TODO: This does not allow shared array buffers, just as the non-stream
+// TextDecoder/Encoder don't. (Bug 1561594)
+Span<const uint8_t> ExtractSpanFromBufferSource(
+ JSContext* aCx, JS::Handle<JS::Value> aBufferSource, ErrorResult& aRv) {
+ RootedUnion<OwningArrayBufferViewOrArrayBuffer> bufferSource(aCx);
+ if (!bufferSource.Init(aCx, aBufferSource)) {
+ aRv.MightThrowJSException();
+ aRv.StealExceptionFromJSContext(aCx);
+ return Span<const uint8_t>();
+ }
+
+ if (bufferSource.IsArrayBufferView()) {
+ ArrayBufferView& view = bufferSource.GetAsArrayBufferView();
+ view.ComputeState();
+ return Span(view.Data(), view.Length());
+ }
+
+ ArrayBuffer& buffer = bufferSource.GetAsArrayBuffer();
+ buffer.ComputeState();
+ return Span(buffer.Data(), buffer.Length());
+}
+
+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
+ MOZ_CAN_RUN_SCRIPT void DecodeSpanAndEnqueue(
+ JSContext* aCx, Span<const uint8_t> aInput, bool aFlush,
+ TransformStreamDefaultController& aController, ErrorResult& aRv) {
+ CheckedInt<nsAString::size_type> needed =
+ mDecoderStream->Decoder()->MaxUTF16BufferLength(aInput.Length());
+ if (!needed.isValid()) {
+ aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+ return;
+ }
+
+ nsString outDecodedString;
+ auto output = outDecodedString.GetMutableData(needed.value(), fallible);
+ if (!output) {
+ aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+ return;
+ }
+
+ mDecoderStream->DecodeNative(aInput, !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 (!xpc::NonVoidStringToJsval(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.
+ // (But here we get a mozilla::Span instead)
+ Span<const uint8_t> input = ExtractSpanFromBufferSource(cx, aChunk, aRv);
+ if (aRv.Failed()) {
+ return;
+ }
+
+ DecodeSpanAndEnqueue(cx, input, 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)
+ DecodeSpanAndEnqueue(cx, Span<const uint8_t>(), 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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