/* -*- 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/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