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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/TextDecoder.h"
#include "mozilla/dom/UnionTypes.h"
#include "mozilla/Encoding.h"
#include "mozilla/UniquePtrExtensions.h"
#include "nsContentUtils.h"
#include <stdint.h>
namespace mozilla::dom {
void TextDecoder::Init(const nsAString& aLabel,
const TextDecoderOptions& aOptions, ErrorResult& aRv) {
// Let encoding be the result of getting an encoding from label.
// If encoding is failure or replacement, throw a RangeError
// (https://encoding.spec.whatwg.org/#dom-textdecoder).
const Encoding* encoding = Encoding::ForLabelNoReplacement(aLabel);
if (!encoding) {
NS_ConvertUTF16toUTF8 label(aLabel);
label.Trim(" \t\n\f\r");
aRv.ThrowRangeError<MSG_ENCODING_NOT_SUPPORTED>(label);
return;
}
InitWithEncoding(WrapNotNull(encoding), aOptions);
}
void TextDecoder::InitWithEncoding(NotNull<const Encoding*> aEncoding,
const TextDecoderOptions& aOptions) {
aEncoding->Name(mEncoding);
// Store the flags passed via our options dictionary.
mFatal = aOptions.mFatal;
mIgnoreBOM = aOptions.mIgnoreBOM;
// Create a decoder object for mEncoding.
if (mIgnoreBOM) {
mDecoder = aEncoding->NewDecoderWithoutBOMHandling();
} else {
mDecoder = aEncoding->NewDecoderWithBOMRemoval();
}
}
void TextDecoderCommon::DecodeNative(Span<const uint8_t> aInput,
const bool aStream,
nsAString& aOutDecodedString,
ErrorResult& aRv) {
aOutDecodedString.Truncate();
CheckedInt<nsAString::size_type> needed =
mDecoder->MaxUTF16BufferLength(aInput.Length());
if (!needed.isValid()) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
auto output = aOutDecodedString.GetMutableData(needed.value(), fallible);
if (!output) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
uint32_t result;
size_t read;
size_t written;
if (mFatal) {
std::tie(result, read, written) =
mDecoder->DecodeToUTF16WithoutReplacement(aInput, *output, !aStream);
if (result != kInputEmpty) {
aRv.ThrowTypeError<MSG_DOM_DECODING_FAILED>();
return;
}
} else {
std::tie(result, read, written, std::ignore) =
mDecoder->DecodeToUTF16(aInput, *output, !aStream);
}
MOZ_ASSERT(result == kInputEmpty);
MOZ_ASSERT(read == aInput.Length());
MOZ_ASSERT(written <= aOutDecodedString.Length());
if (!aOutDecodedString.SetLength(written, fallible)) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
// If the internal streaming flag of the decoder object is not set,
// then reset the encoding algorithm state to the default values
if (!aStream) {
if (mIgnoreBOM) {
mDecoder->Encoding()->NewDecoderWithoutBOMHandlingInto(*mDecoder);
} else {
mDecoder->Encoding()->NewDecoderWithBOMRemovalInto(*mDecoder);
}
}
}
void TextDecoder::Decode(const Optional<ArrayBufferViewOrArrayBuffer>& aBuffer,
const TextDecodeOptions& aOptions,
nsAString& aOutDecodedString, ErrorResult& aRv) {
if (!aBuffer.WasPassed()) {
DecodeNative(nullptr, aOptions.mStream, aOutDecodedString, aRv);
return;
}
ProcessTypedArrays(aBuffer.Value(), [&](const Span<uint8_t>& aData,
JS::AutoCheckCannotGC&&) {
DecodeNative(aData, aOptions.mStream, aOutDecodedString, aRv);
});
}
void TextDecoderCommon::GetEncoding(nsAString& aEncoding) {
CopyASCIItoUTF16(mEncoding, aEncoding);
nsContentUtils::ASCIIToLower(aEncoding);
}
} // namespace mozilla::dom
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