ByteArray Compress(const ByteArrayView view, const int32 compressionLevel)
{
const size_t bufferSize = ZSTD_compressBound(view.size());
Array<Byte> buffer(bufferSize);
const size_t result = ZSTD_compress(buffer.data(), buffer.size(), view.data(), view.size(), compressionLevel);
if (ZSTD_isError(result))
{
return ByteArray();
}
buffer.resize(result);
buffer.shrink_to_fit();
return ByteArray(std::move(buffer));
}
ByteArray Decompress(const ByteArrayView view)
{
const uint64 originalSize = ZSTD_getDecompressedSize(view.data(), view.size());
if (originalSize == 0)
{
return ByteArray();
}
Array<Byte> outputBuffer(static_cast<size_t>(originalSize));
const size_t decompressedSize = ZSTD_decompress(outputBuffer.data(), outputBuffer.size(), view.data(), view.size());
if (originalSize != decompressedSize)
{
return ByteArray();
}
return ByteArray(std::move(outputBuffer));
}
bool DecompressToFile(const ByteArrayView view, const FilePath& outputPath)
{
const size_t inputBufferSize = ZSTD_DStreamInSize();
const auto pInputBuffer = std::make_unique<Byte[]>(inputBufferSize);
const size_t outputBufferSize = ZSTD_DStreamOutSize();
const auto pOutputBuffer = std::make_unique<Byte[]>(outputBufferSize);
ZSTD_DStream* const dStream = ZSTD_createDStream();
if (!dStream)
{
return false;
}
const size_t initResult = ZSTD_initDStream(dStream);
if (ZSTD_isError(initResult))
{
ZSTD_freeDStream(dStream);
return false;
}
size_t toRead = initResult;
BinaryWriter writer(outputPath);
if (!writer)
{
ZSTD_freeDStream(dStream);
return false;
}
ReaderView reader(view.data(), view.size());
for (;;)
{
const size_t read = std::min<size_t>(toRead, view.size() - static_cast<size_t>(reader.getPos()));
if (read == 0)
{
break;
}
reader.read(pInputBuffer.get(), read);
ZSTD_inBuffer input = { pInputBuffer.get(), read, 0 };
while (input.pos < input.size)
{
ZSTD_outBuffer output = { pOutputBuffer.get(), outputBufferSize, 0 };
toRead = ZSTD_decompressStream(dStream, &output, &input);
if (ZSTD_isError(toRead))
{
writer.clear();
ZSTD_freeDStream(dStream);
return false;
}
writer.write(pOutputBuffer.get(), output.pos);
}
}
ZSTD_freeDStream(dStream);
return true;
}
/// <summary>
/// データを Base64 エンコードします。
/// </summary>
/// <param name="view">
/// エンコードするデータ
/// </param>
/// <returns>
/// エンコードされたテキストデータ、エンコードに失敗した場合空の文字列
/// </returns>
inline String Encode(const ByteArrayView view)
{
return Encode(view.data(), view.size());
}
/// <summary>
/// ファイルにデータを書き込みます。
/// </summary>
/// <param name="view">
/// 書き込むデータ
/// </param>
/// <returns>
/// 実際に書き込んだサイズ（バイト）
/// </returns>
int64 write(ByteArrayView view)
{
return write(view.data(), view.size());
}
