mirror of
https://github.com/mozilla/gecko-dev.git
synced 2025-11-04 02:09:05 +02:00
4b2a32ee5c
Depends on D182644 Differential Revision: https://phabricator.services.mozilla.com/D182645
240 lines
8.6 KiB
C++
240 lines
8.6 KiB
C++
/* -*- 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/TextEncoderStream.h"
|
||
|
||
#include "js/ArrayBuffer.h"
|
||
#include "js/experimental/TypedData.h"
|
||
#include "nsIGlobalObject.h"
|
||
#include "mozilla/Encoding.h"
|
||
#include "mozilla/dom/BindingUtils.h"
|
||
#include "mozilla/dom/TextEncoderStreamBinding.h"
|
||
#include "mozilla/dom/TransformerCallbackHelpers.h"
|
||
#include "mozilla/dom/TransformStream.h"
|
||
|
||
namespace mozilla::dom {
|
||
|
||
NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(TextEncoderStream, mGlobal, mStream)
|
||
NS_IMPL_CYCLE_COLLECTING_ADDREF(TextEncoderStream)
|
||
NS_IMPL_CYCLE_COLLECTING_RELEASE(TextEncoderStream)
|
||
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TextEncoderStream)
|
||
NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
|
||
NS_INTERFACE_MAP_ENTRY(nsISupports)
|
||
NS_INTERFACE_MAP_END
|
||
|
||
TextEncoderStream::TextEncoderStream(nsISupports* aGlobal,
|
||
TransformStream& aStream)
|
||
: mGlobal(aGlobal), mStream(&aStream) {
|
||
// See the comment in EncodeNative() about why this uses a decoder instead of
|
||
// `UTF_8_ENCODING->NewEncoder()`.
|
||
// XXX: We have to consciously choose 16LE/BE because we ultimately have to read
|
||
// char16_t* as uint8_t*. See the same comment.
|
||
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
|
||
mDecoder = UTF_16LE_ENCODING->NewDecoder();
|
||
#else
|
||
mDecoder = UTF_16BE_ENCODING->NewDecoder();
|
||
#endif
|
||
}
|
||
|
||
TextEncoderStream::~TextEncoderStream() = default;
|
||
|
||
JSObject* TextEncoderStream::WrapObject(JSContext* aCx,
|
||
JS::Handle<JSObject*> aGivenProto) {
|
||
return TextEncoderStream_Binding::Wrap(aCx, this, aGivenProto);
|
||
}
|
||
|
||
// Note that the most of the encoding algorithm is implemented in
|
||
// mozilla::Decoder (see the comment in EncodeNative()), and this is mainly
|
||
// about calling it properly.
|
||
static void EncodeNative(JSContext* aCx, mozilla::Decoder* aDecoder,
|
||
Span<const char16_t> aInput, const bool aFlush,
|
||
JS::MutableHandle<JSObject*> aOutputArrayBufferView,
|
||
ErrorResult& aRv) {
|
||
// XXX: Adjust the length since Decoder always accepts uint8_t (whereas
|
||
// Encoder also accepts char16_t, see below).
|
||
if (aInput.Length() > SIZE_MAX / 2) {
|
||
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
|
||
return;
|
||
}
|
||
size_t lengthU8 = aInput.Length() * 2;
|
||
|
||
CheckedInt<nsAString::size_type> needed =
|
||
aDecoder->MaxUTF8BufferLength(lengthU8);
|
||
if (!needed.isValid()) {
|
||
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
|
||
return;
|
||
}
|
||
|
||
UniquePtr<uint8_t[], JS::FreePolicy> buffer(
|
||
static_cast<uint8_t*>(JS_malloc(aCx, needed.value())));
|
||
if (!buffer) {
|
||
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
|
||
return;
|
||
}
|
||
|
||
mozilla::Span<uint8_t> input((uint8_t*)aInput.data(), lengthU8);
|
||
mozilla::Span<uint8_t> output(buffer, needed.value());
|
||
|
||
// This originally wanted to use mozilla::Encoder::Encode() that accepts
|
||
// char16_t*, but it lacks the pending-high-surrogate feature to properly
|
||
// implement
|
||
// https://encoding.spec.whatwg.org/#convert-code-unit-to-scalar-value.
|
||
// See also https://github.com/hsivonen/encoding_rs/issues/82 about the
|
||
// reasoning.
|
||
// XXX: The code is more verbose here since we need to convert to
|
||
// uint8_t* which is the only type mozilla::Decoder accepts.
|
||
uint32_t result;
|
||
size_t read;
|
||
size_t written;
|
||
std::tie(result, read, written, std::ignore) =
|
||
aDecoder->DecodeToUTF8(input, output, aFlush);
|
||
MOZ_ASSERT(result == kInputEmpty);
|
||
MOZ_ASSERT(read == lengthU8);
|
||
MOZ_ASSERT(written <= needed.value());
|
||
|
||
// https://encoding.spec.whatwg.org/#encode-and-enqueue-a-chunk
|
||
// Step 4.2.2.1. Let chunk be a Uint8Array object wrapping an ArrayBuffer
|
||
// containing output.
|
||
JS::Rooted<JSObject*> arrayBuffer(
|
||
aCx, JS::NewArrayBufferWithContents(aCx, written, std::move(buffer)));
|
||
if (!arrayBuffer.get()) {
|
||
JS_ClearPendingException(aCx);
|
||
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
|
||
return;
|
||
}
|
||
aOutputArrayBufferView.set(JS_NewUint8ArrayWithBuffer(
|
||
aCx, arrayBuffer, 0, static_cast<int64_t>(written)));
|
||
if (!aOutputArrayBufferView.get()) {
|
||
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
|
||
return;
|
||
}
|
||
}
|
||
|
||
class TextEncoderStreamAlgorithms : public TransformerAlgorithmsWrapper {
|
||
NS_DECL_ISUPPORTS_INHERITED
|
||
NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(TextEncoderStreamAlgorithms,
|
||
TransformerAlgorithmsBase)
|
||
|
||
void SetEncoderStream(TextEncoderStream& aStream) {
|
||
mEncoderStream = &aStream;
|
||
}
|
||
|
||
// The common part of encode-and-enqueue and encode-and-flush.
|
||
// https://encoding.spec.whatwg.org/#decode-and-enqueue-a-chunk
|
||
MOZ_CAN_RUN_SCRIPT void EncodeAndEnqueue(
|
||
JSContext* aCx, const nsAString& aInput,
|
||
TransformStreamDefaultController& aController, bool aFlush,
|
||
ErrorResult& aRv) {
|
||
JS::Rooted<JSObject*> outView(aCx);
|
||
// Passing a Decoder for a reason, see the comments in the method.
|
||
EncodeNative(aCx, mEncoderStream->Decoder(), aInput, aFlush, &outView, aRv);
|
||
|
||
if (JS_GetTypedArrayLength(outView) > 0) {
|
||
// Step 4.2.2.2. Enqueue chunk into encoder’s transform.
|
||
JS::Rooted<JS::Value> value(aCx, JS::ObjectValue(*outView));
|
||
aController.Enqueue(aCx, value, aRv);
|
||
}
|
||
}
|
||
|
||
// https://encoding.spec.whatwg.org/#dom-textencoderstream
|
||
MOZ_CAN_RUN_SCRIPT void TransformCallbackImpl(
|
||
JS::Handle<JS::Value> aChunk,
|
||
TransformStreamDefaultController& aController,
|
||
ErrorResult& aRv) override {
|
||
// Step 2. Let transformAlgorithm be an algorithm which takes a chunk
|
||
// argument and runs the encode and enqueue a chunk algorithm with this and
|
||
// chunk.
|
||
|
||
AutoJSAPI jsapi;
|
||
if (!jsapi.Init(aController.GetParentObject())) {
|
||
aRv.ThrowUnknownError("Internal error");
|
||
return;
|
||
}
|
||
JSContext* cx = jsapi.cx();
|
||
|
||
// https://encoding.spec.whatwg.org/#encode-and-enqueue-a-chunk
|
||
|
||
// Step 1. Let input be the result of converting chunk to a DOMString.
|
||
// Step 2. Convert input to an I/O queue of code units.
|
||
nsString str;
|
||
if (!ConvertJSValueToString(cx, aChunk, eStringify, eStringify, str)) {
|
||
aRv.MightThrowJSException();
|
||
aRv.StealExceptionFromJSContext(cx);
|
||
return;
|
||
}
|
||
|
||
EncodeAndEnqueue(cx, str, aController, false, aRv);
|
||
}
|
||
|
||
// https://encoding.spec.whatwg.org/#dom-textencoderstream
|
||
MOZ_CAN_RUN_SCRIPT void FlushCallbackImpl(
|
||
TransformStreamDefaultController& aController,
|
||
ErrorResult& aRv) override {
|
||
// Step 3. Let flushAlgorithm be an algorithm which runs the encode and
|
||
// flush algorithm with this.
|
||
|
||
AutoJSAPI jsapi;
|
||
if (!jsapi.Init(aController.GetParentObject())) {
|
||
aRv.ThrowUnknownError("Internal error");
|
||
return;
|
||
}
|
||
JSContext* cx = jsapi.cx();
|
||
|
||
// The spec manually manages pending high surrogate here, but let's call the
|
||
// encoder as it's managed there.
|
||
EncodeAndEnqueue(cx, u""_ns, aController, true, aRv);
|
||
}
|
||
|
||
private:
|
||
~TextEncoderStreamAlgorithms() override = default;
|
||
|
||
RefPtr<TextEncoderStream> mEncoderStream;
|
||
};
|
||
|
||
NS_IMPL_CYCLE_COLLECTION_INHERITED(TextEncoderStreamAlgorithms,
|
||
TransformerAlgorithmsBase, mEncoderStream)
|
||
NS_IMPL_ADDREF_INHERITED(TextEncoderStreamAlgorithms, TransformerAlgorithmsBase)
|
||
NS_IMPL_RELEASE_INHERITED(TextEncoderStreamAlgorithms,
|
||
TransformerAlgorithmsBase)
|
||
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TextEncoderStreamAlgorithms)
|
||
NS_INTERFACE_MAP_END_INHERITING(TransformerAlgorithmsBase)
|
||
|
||
// https://encoding.spec.whatwg.org/#dom-textencoderstream
|
||
already_AddRefed<TextEncoderStream> TextEncoderStream::Constructor(
|
||
const GlobalObject& aGlobal, ErrorResult& aRv) {
|
||
// Step 1. Set this’s encoder to an instance of the UTF-8 encoder.
|
||
|
||
// Step 2-3
|
||
auto algorithms = MakeRefPtr<TextEncoderStreamAlgorithms>();
|
||
|
||
// Step 4-5
|
||
RefPtr<TransformStream> transformStream =
|
||
TransformStream::CreateGeneric(aGlobal, *algorithms, aRv);
|
||
if (aRv.Failed()) {
|
||
return nullptr;
|
||
}
|
||
|
||
// Step 6. Set this’s transform to transformStream.
|
||
// (Done in the constructor)
|
||
auto encoderStream =
|
||
MakeRefPtr<TextEncoderStream>(aGlobal.GetAsSupports(), *transformStream);
|
||
algorithms->SetEncoderStream(*encoderStream);
|
||
return encoderStream.forget();
|
||
}
|
||
|
||
ReadableStream* TextEncoderStream::Readable() const {
|
||
return mStream->Readable();
|
||
}
|
||
|
||
WritableStream* TextEncoderStream::Writable() const {
|
||
return mStream->Writable();
|
||
}
|
||
|
||
void TextEncoderStream::GetEncoding(nsCString& aRetVal) const {
|
||
aRetVal.AssignLiteral("utf-8");
|
||
}
|
||
|
||
} // namespace mozilla::dom
|