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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/EncodingUtils.h"
#include "mozilla/dom/UnionTypes.h"
#include "mozilla/UniquePtrExtensions.h"
#include "nsContentUtils.h"
#include <stdint.h>
namespace mozilla {
namespace dom {
static const char16_t kReplacementChar = static_cast<char16_t>(0xFFFD);
void
TextDecoder::Init(const nsAString& aLabel, const bool aFatal,
ErrorResult& aRv)
{
nsAutoCString encoding;
// 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).
if (!EncodingUtils::FindEncodingForLabelNoReplacement(aLabel, encoding)) {
nsAutoString label(aLabel);
EncodingUtils::TrimSpaceCharacters(label);
aRv.ThrowRangeError<MSG_ENCODING_NOT_SUPPORTED>(label);
return;
}
InitWithEncoding(encoding, aFatal);
}
void
TextDecoder::InitWithEncoding(const nsACString& aEncoding, const bool aFatal)
{
mEncoding = aEncoding;
// If the constructor is called with an options argument,
// and the fatal property of the dictionary is set,
// set the internal fatal flag of the decoder object.
mFatal = aFatal;
// Create a decoder object for mEncoding.
mDecoder = EncodingUtils::DecoderForEncoding(mEncoding);
if (mFatal) {
mDecoder->SetInputErrorBehavior(nsIUnicodeDecoder::kOnError_Signal);
}
}
void
TextDecoder::Decode(const char* aInput, const int32_t aLength,
const bool aStream, nsAString& aOutDecodedString,
ErrorResult& aRv)
{
aOutDecodedString.Truncate();
// Run or resume the decoder algorithm of the decoder object's encoder.
int32_t outLen;
nsresult rv = mDecoder->GetMaxLength(aInput, aLength, &outLen);
if (NS_FAILED(rv)) {
aRv.Throw(rv);
return;
}
// Need a fallible allocator because the caller may be a content
// and the content can specify the length of the string.
auto buf = MakeUniqueFallible<char16_t[]>(outLen + 1);
if (!buf) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
int32_t length = aLength;
rv = mDecoder->Convert(aInput, &length, buf.get(), &outLen);
MOZ_ASSERT(mFatal || rv != NS_ERROR_ILLEGAL_INPUT);
buf[outLen] = 0;
if (!aOutDecodedString.Append(buf.get(), outLen, 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) {
mDecoder->Reset();
if (rv == NS_OK_UDEC_MOREINPUT) {
if (mFatal) {
aRv.ThrowTypeError<MSG_DOM_DECODING_FAILED>();
} else {
// Need to emit a decode error manually
// to simulate the EOF handling of the Encoding spec.
aOutDecodedString.Append(kReplacementChar);
}
}
}
if (NS_FAILED(rv)) {
aRv.ThrowTypeError<MSG_DOM_DECODING_FAILED>();
}
}
void
TextDecoder::Decode(const Optional<ArrayBufferViewOrArrayBuffer>& aBuffer,
const TextDecodeOptions& aOptions,
nsAString& aOutDecodedString,
ErrorResult& aRv)
{
if (!aBuffer.WasPassed()) {
Decode(nullptr, 0, aOptions.mStream, aOutDecodedString, aRv);
return;
}
const ArrayBufferViewOrArrayBuffer& buf = aBuffer.Value();
uint8_t* data;
uint32_t length;
if (buf.IsArrayBufferView()) {
buf.GetAsArrayBufferView().ComputeLengthAndData();
data = buf.GetAsArrayBufferView().Data();
length = buf.GetAsArrayBufferView().Length();
} else {
MOZ_ASSERT(buf.IsArrayBuffer());
buf.GetAsArrayBuffer().ComputeLengthAndData();
data = buf.GetAsArrayBuffer().Data();
length = buf.GetAsArrayBuffer().Length();
}
// The other Decode signature takes a signed int, because that's
// what nsIUnicodeDecoder::Convert takes as the length. Throw if
// our length is too big.
if (length > INT32_MAX) {
aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
return;
}
Decode(reinterpret_cast<char*>(data), length, aOptions.mStream,
aOutDecodedString, aRv);
}
void
TextDecoder::GetEncoding(nsAString& aEncoding)
{
CopyASCIItoUTF16(mEncoding, aEncoding);
nsContentUtils::ASCIIToLower(aEncoding);
}
} // namespace dom
} // namespace mozilla
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