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/*
* Copyright (C) 2004, 2006, 2008, 2010 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif
#include "third_party/blink/renderer/platform/wtf/text/text_codec_utf16.h"
#include <unicode/utf16.h>
#include <memory>
#include "third_party/blink/renderer/platform/wtf/text/character_names.h"
#include "third_party/blink/renderer/platform/wtf/text/string_buffer.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
namespace WTF {
void TextCodecUTF16::RegisterEncodingNames(EncodingNameRegistrar registrar) {
registrar("UTF-16LE", "UTF-16LE");
registrar("UTF-16BE", "UTF-16BE");
registrar("ISO-10646-UCS-2", "UTF-16LE");
registrar("UCS-2", "UTF-16LE");
registrar("UTF-16", "UTF-16LE");
registrar("Unicode", "UTF-16LE");
registrar("csUnicode", "UTF-16LE");
registrar("unicodeFEFF", "UTF-16LE");
registrar("unicodeFFFE", "UTF-16BE");
}
static std::unique_ptr<TextCodec> NewStreamingTextDecoderUTF16LE(
const TextEncoding&,
const void*) {
return std::make_unique<TextCodecUTF16>(true);
}
static std::unique_ptr<TextCodec> NewStreamingTextDecoderUTF16BE(
const TextEncoding&,
const void*) {
return std::make_unique<TextCodecUTF16>(false);
}
void TextCodecUTF16::RegisterCodecs(TextCodecRegistrar registrar) {
registrar("UTF-16LE", NewStreamingTextDecoderUTF16LE, nullptr);
registrar("UTF-16BE", NewStreamingTextDecoderUTF16BE, nullptr);
}
String TextCodecUTF16::Decode(base::span<const uint8_t> bytes,
FlushBehavior flush,
bool,
bool& saw_error) {
// For compatibility reasons, ignore flush from fetch EOF.
const bool really_flush = flush != FlushBehavior::kDoNotFlush &&
flush != FlushBehavior::kFetchEOF;
if (bytes.empty()) {
if (really_flush && (have_lead_byte_ || have_lead_surrogate_)) {
have_lead_byte_ = have_lead_surrogate_ = false;
saw_error = true;
return String(base::span_from_ref(kReplacementCharacter));
}
return String();
}
const uint8_t* p = bytes.data();
const wtf_size_t num_bytes = bytes.size() + have_lead_byte_;
const bool will_have_extra_byte = num_bytes & 1;
const wtf_size_t num_chars_in = num_bytes / 2;
const wtf_size_t max_chars_out =
num_chars_in + (have_lead_surrogate_ ? 1 : 0) +
(really_flush && will_have_extra_byte ? 1 : 0);
StringBuffer<UChar> buffer(max_chars_out);
UChar* q = buffer.Characters();
for (wtf_size_t i = 0; i < num_chars_in; ++i) {
UChar c;
if (have_lead_byte_) {
c = little_endian_ ? (lead_byte_ | (p[0] << 8))
: ((lead_byte_ << 8) | p[0]);
have_lead_byte_ = false;
++p;
} else {
c = little_endian_ ? (p[0] | (p[1] << 8)) : ((p[0] << 8) | p[1]);
p += 2;
}
// TODO(jsbell): If necessary for performance, m_haveLeadByte handling
// can be pulled out and this loop split into distinct cases for
// big/little endian. The logic from here to the end of the loop is
// constant with respect to m_haveLeadByte and m_littleEndian.
if (have_lead_surrogate_ && U_IS_TRAIL(c)) {
*q++ = lead_surrogate_;
have_lead_surrogate_ = false;
*q++ = c;
} else {
if (have_lead_surrogate_) {
have_lead_surrogate_ = false;
saw_error = true;
*q++ = kReplacementCharacter;
}
if (U_IS_LEAD(c)) {
have_lead_surrogate_ = true;
lead_surrogate_ = c;
} else if (U_IS_TRAIL(c)) {
saw_error = true;
*q++ = kReplacementCharacter;
} else {
*q++ = c;
}
}
}
DCHECK(!have_lead_byte_);
if (will_have_extra_byte) {
have_lead_byte_ = true;
lead_byte_ = p[0];
}
if (really_flush && (have_lead_byte_ || have_lead_surrogate_)) {
have_lead_byte_ = have_lead_surrogate_ = false;
saw_error = true;
*q++ = kReplacementCharacter;
}
buffer.Shrink(static_cast<wtf_size_t>(q - buffer.Characters()));
return String::Adopt(buffer);
}
std::string TextCodecUTF16::Encode(base::span<const UChar> characters,
UnencodableHandling) {
// We need to be sure we can double the length without overflowing.
// Since the passed-in length is the length of an actual existing
// character buffer, each character is two bytes, and we know
// the buffer doesn't occupy the entire address space, we can
// assert here that doubling the length does not overflow wtf_size_t
// and there's no need for a runtime check.
DCHECK_LE(characters.size(), std::numeric_limits<wtf_size_t>::max() / 2);
std::string result(characters.size() * 2, '\0');
if (little_endian_) {
for (size_t i = 0; i < characters.size(); ++i) {
UChar c = characters[i];
result[i * 2] = static_cast<char>(c);
result[i * 2 + 1] = c >> 8;
}
} else {
for (size_t i = 0; i < characters.size(); ++i) {
UChar c = characters[i];
result[i * 2] = c >> 8;
result[i * 2 + 1] = static_cast<char>(c);
}
}
return result;
}
std::string TextCodecUTF16::Encode(base::span<const LChar> characters,
UnencodableHandling) {
// In the LChar case, we do actually need to perform this check in release. :)
CHECK_LE(characters.size(), std::numeric_limits<wtf_size_t>::max() / 2);
std::string result(characters.size() * 2, '\0');
if (little_endian_) {
for (size_t i = 0; i < characters.size(); ++i) {
result[i * 2] = characters[i];
result[i * 2 + 1] = 0;
}
} else {
for (size_t i = 0; i < characters.size(); ++i) {
result[i * 2] = 0;
result[i * 2 + 1] = characters[i];
}
}
return result;
}
} // namespace WTF
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