michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "mozilla/dom/TextDecoder.h"
michael@0: #include "mozilla/dom/EncodingUtils.h"
michael@0: #include "nsContentUtils.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: 
michael@0: static const char16_t kReplacementChar = static_cast<char16_t>(0xFFFD);
michael@0: 
michael@0: void
michael@0: TextDecoder::Init(const nsAString& aLabel, const bool aFatal,
michael@0:                   ErrorResult& aRv)
michael@0: {
michael@0:   nsAutoString label(aLabel);
michael@0:   EncodingUtils::TrimSpaceCharacters(label);
michael@0: 
michael@0:   nsAutoCString encoding;
michael@0:   // Let encoding be the result of getting an encoding from label.
michael@0:   // If encoding is failure or replacement, throw a TypeError.
michael@0:   if (!EncodingUtils::FindEncodingForLabel(label, encoding) ||
michael@0:       encoding.EqualsLiteral("replacement")) {
michael@0:     aRv.ThrowTypeError(MSG_ENCODING_NOT_SUPPORTED, &label);
michael@0:     return;
michael@0:   }
michael@0:   InitWithEncoding(encoding, aFatal);
michael@0: }
michael@0: 
michael@0: void
michael@0: TextDecoder::InitWithEncoding(const nsACString& aEncoding, const bool aFatal)
michael@0: {
michael@0:   mEncoding = aEncoding;
michael@0:   // If the constructor is called with an options argument,
michael@0:   // and the fatal property of the dictionary is set,
michael@0:   // set the internal fatal flag of the decoder object.
michael@0:   mFatal = aFatal;
michael@0: 
michael@0:   // Create a decoder object for mEncoding.
michael@0:   mDecoder = EncodingUtils::DecoderForEncoding(mEncoding);
michael@0: 
michael@0:   if (mFatal) {
michael@0:     mDecoder->SetInputErrorBehavior(nsIUnicodeDecoder::kOnError_Signal);
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: TextDecoder::Decode(const char* aInput, const int32_t aLength,
michael@0:                     const bool aStream, nsAString& aOutDecodedString,
michael@0:                     ErrorResult& aRv)
michael@0: {
michael@0:   aOutDecodedString.Truncate();
michael@0: 
michael@0:   // Run or resume the decoder algorithm of the decoder object's encoder.
michael@0:   int32_t outLen;
michael@0:   nsresult rv = mDecoder->GetMaxLength(aInput, aLength, &outLen);
michael@0:   if (NS_FAILED(rv)) {
michael@0:     aRv.Throw(rv);
michael@0:     return;
michael@0:   }
michael@0:   // Need a fallible allocator because the caller may be a content
michael@0:   // and the content can specify the length of the string.
michael@0:   static const fallible_t fallible = fallible_t();
michael@0:   nsAutoArrayPtr<char16_t> buf(new (fallible) char16_t[outLen + 1]);
michael@0:   if (!buf) {
michael@0:     aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   int32_t length = aLength;
michael@0:   rv = mDecoder->Convert(aInput, &length, buf, &outLen);
michael@0:   MOZ_ASSERT(mFatal || rv != NS_ERROR_ILLEGAL_INPUT);
michael@0:   buf[outLen] = 0;
michael@0:   aOutDecodedString.Append(buf, outLen);
michael@0: 
michael@0:   // If the internal streaming flag of the decoder object is not set,
michael@0:   // then reset the encoding algorithm state to the default values
michael@0:   if (!aStream) {
michael@0:     mDecoder->Reset();
michael@0:     if (rv == NS_OK_UDEC_MOREINPUT) {
michael@0:       if (mFatal) {
michael@0:         aRv.Throw(NS_ERROR_DOM_ENCODING_DECODE_ERR);
michael@0:       } else {
michael@0:         // Need to emit a decode error manually
michael@0:         // to simulate the EOF handling of the Encoding spec.
michael@0:         aOutDecodedString.Append(kReplacementChar);
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   if (NS_FAILED(rv)) {
michael@0:     aRv.Throw(NS_ERROR_DOM_ENCODING_DECODE_ERR);
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: TextDecoder::GetEncoding(nsAString& aEncoding)
michael@0: {
michael@0:   CopyASCIItoUTF16(mEncoding, aEncoding);
michael@0:   nsContentUtils::ASCIIToLower(aEncoding);
michael@0: }
michael@0: 
michael@0: } // dom
michael@0: } // mozilla