Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim: set ts=8 sts=2 et sw=2 tw=80: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #include "mozilla/dom/TextDecoder.h"
       8             : #include "mozilla/dom/UnionTypes.h"
       9             : #include "mozilla/Encoding.h"
      10             : #include "mozilla/UniquePtrExtensions.h"
      11             : #include "nsContentUtils.h"
      12             : #include <stdint.h>
      13             : 
      14             : namespace mozilla {
      15             : namespace dom {
      16             : 
      17             : static const char16_t kReplacementChar = static_cast<char16_t>(0xFFFD);
      18             : 
      19             : void
      20           0 : TextDecoder::Init(const nsAString& aLabel, const bool aFatal,
      21             :                   ErrorResult& aRv)
      22             : {
      23             :   // Let encoding be the result of getting an encoding from label.
      24             :   // If encoding is failure or replacement, throw a RangeError
      25             :   // (https://encoding.spec.whatwg.org/#dom-textdecoder).
      26           0 :   const Encoding* encoding = Encoding::ForLabelNoReplacement(aLabel);
      27           0 :   if (!encoding) {
      28           0 :     nsAutoString label(aLabel);
      29           0 :     label.Trim(" \t\n\f\r");
      30           0 :     aRv.ThrowRangeError<MSG_ENCODING_NOT_SUPPORTED>(label);
      31           0 :     return;
      32             :   }
      33           0 :   InitWithEncoding(WrapNotNull(encoding), aFatal);
      34             : }
      35             : 
      36             : void
      37           0 : TextDecoder::InitWithEncoding(NotNull<const Encoding*> aEncoding,
      38             :                               const bool aFatal)
      39             : {
      40           0 :   aEncoding->Name(mEncoding);
      41             :   // If the constructor is called with an options argument,
      42             :   // and the fatal property of the dictionary is set,
      43             :   // set the internal fatal flag of the decoder object.
      44           0 :   mFatal = aFatal;
      45             : 
      46             :   // Create a decoder object for mEncoding.
      47           0 :   mDecoder = aEncoding->NewDecoderWithBOMRemoval();
      48           0 : }
      49             : 
      50             : void
      51           0 : TextDecoder::Decode(Span<const uint8_t> aInput,
      52             :                     const bool aStream,
      53             :                     nsAString& aOutDecodedString,
      54             :                     ErrorResult& aRv)
      55             : {
      56           0 :   aOutDecodedString.Truncate();
      57             : 
      58           0 :   CheckedInt<size_t> needed = mDecoder->MaxUTF16BufferLength(aInput.Length());
      59           0 :   if (!needed.isValid() ||
      60           0 :       needed.value() > MaxValue<nsAString::size_type>::value) {
      61           0 :     aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
      62           0 :     return;
      63             :   }
      64             : 
      65           0 :   if (!aOutDecodedString.SetLength(needed.value(), fallible)) {
      66           0 :     aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
      67           0 :     return;
      68             :   }
      69             : 
      70             :   uint32_t result;
      71             :   size_t read;
      72             :   size_t written;
      73             :   bool hadErrors;
      74           0 :   if (mFatal) {
      75           0 :     Tie(result, read, written) = mDecoder->DecodeToUTF16WithoutReplacement(
      76           0 :       aInput, aOutDecodedString, !aStream);
      77           0 :     if (result != kInputEmpty) {
      78           0 :       aRv.ThrowTypeError<MSG_DOM_DECODING_FAILED>();
      79           0 :       return;
      80             :     }
      81             :   } else {
      82           0 :     Tie(result, read, written, hadErrors) =
      83           0 :       mDecoder->DecodeToUTF16(aInput, aOutDecodedString, !aStream);
      84             :   }
      85           0 :   MOZ_ASSERT(result == kInputEmpty);
      86           0 :   MOZ_ASSERT(read == aInput.Length());
      87           0 :   MOZ_ASSERT(written <= aOutDecodedString.Length());
      88             :   Unused << hadErrors;
      89             : 
      90           0 :   if (!aOutDecodedString.SetLength(written, fallible)) {
      91           0 :     aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
      92           0 :     return;
      93             :   }
      94             : 
      95             :   // If the internal streaming flag of the decoder object is not set,
      96             :   // then reset the encoding algorithm state to the default values
      97           0 :   if (!aStream) {
      98           0 :     mDecoder->Encoding()->NewDecoderWithBOMRemovalInto(*mDecoder);
      99             :   }
     100             : }
     101             : 
     102             : void
     103           0 : TextDecoder::Decode(const Optional<ArrayBufferViewOrArrayBuffer>& aBuffer,
     104             :                     const TextDecodeOptions& aOptions,
     105             :                     nsAString& aOutDecodedString,
     106             :                     ErrorResult& aRv)
     107             : {
     108           0 :   if (!aBuffer.WasPassed()) {
     109           0 :     Decode(nullptr, aOptions.mStream, aOutDecodedString, aRv);
     110           0 :     return;
     111             :   }
     112           0 :   const ArrayBufferViewOrArrayBuffer& buf = aBuffer.Value();
     113             :   uint8_t* data;
     114             :   uint32_t length;
     115           0 :   if (buf.IsArrayBufferView()) {
     116           0 :     buf.GetAsArrayBufferView().ComputeLengthAndData();
     117           0 :     data = buf.GetAsArrayBufferView().Data();
     118           0 :     length = buf.GetAsArrayBufferView().Length();
     119             :   } else {
     120           0 :     MOZ_ASSERT(buf.IsArrayBuffer());
     121           0 :     buf.GetAsArrayBuffer().ComputeLengthAndData();
     122           0 :     data = buf.GetAsArrayBuffer().Data();
     123           0 :     length = buf.GetAsArrayBuffer().Length();
     124             :   }
     125           0 :   Decode(MakeSpan(data, length), aOptions.mStream, aOutDecodedString, aRv);
     126             : }
     127             : 
     128             : void
     129           0 : TextDecoder::GetEncoding(nsAString& aEncoding)
     130             : {
     131           0 :   CopyASCIItoUTF16(mEncoding, aEncoding);
     132           0 :   nsContentUtils::ASCIIToLower(aEncoding);
     133           0 : }
     134             : 
     135             : } // namespace dom
     136             : } // namespace mozilla