public unsafe int Wrap(ReadOnlySpan <byte> src, Span <byte> dst, int compressionLevel = 3)
{
if (src.Length == 0)
{
return(0);
}
UIntPtr dstSize;
fixed(byte *dstPtr = dst)
fixed(byte *srcPtr = src)
{
if (Options.Cdict == IntPtr.Zero)
{
dstSize = ExternMethods.ZSTD_compressCCtx(cctx, dstPtr, (UIntPtr)dst.Length, srcPtr, (UIntPtr)src.Length,
compressionLevel);
}
else
{
dstSize = ExternMethods.ZSTD_compress_usingCDict(cctx, dstPtr, (UIntPtr)dst.Length, srcPtr,
(UIntPtr)src.Length, Options.Cdict);
}
}
ReturnValueExtensions.EnsureZdictSuccess(dstSize);
return((int)dstSize);
}
private void Dispose(bool disposing)
{
if (Ddict != IntPtr.Zero)
{
ExternMethods.ZSTD_freeDDict(Ddict);
Ddict = IntPtr.Zero;
}
}
internal static UIntPtr EnsureZdictSuccess(UIntPtr returnValue)
{
if (ExternMethods.ZDICT_isError(returnValue) != 0)
{
ThrowException(returnValue, Marshal.PtrToStringAnsi(ExternMethods.ZDICT_getErrorName(returnValue)));
}
return(returnValue);
}
private void Dispose(bool disposing)
{
if (disposed)
{
return;
}
ExternMethods.ZSTD_freeCCtx(cctx);
disposed = true;
}
public unsafe ZstdDecompressionOptions(byte[] dict)
{
Dictionary = dict;
fixed(byte *ptr = dict)
{
if (dict != null)
{
Ddict = ExternMethods.ZSTD_createDDict(ptr, (UIntPtr)dict.Length).EnsureZstdSuccess();
}
else
{
GC.SuppressFinalize(this); // No unmanaged resources
}
}
}
public static byte[] TrainFromBuffer(IEnumerable <byte[]> samples, int dictCapacity = DefaultDictCapacity)
{
var ms = new MemoryStream();
var samplesSizes = samples.Select(sample =>
{
ms.Write(sample, 0, sample.Length);
return((UIntPtr)sample.Length);
}).ToArray();
var dictBuffer = new byte[dictCapacity];
var dictSize = ExternMethods.ZDICT_trainFromBuffer(dictBuffer, (UIntPtr)dictCapacity, ms.ToArray(), samplesSizes, (uint)samplesSizes.Length);
ReturnValueExtensions.EnsureZdictSuccess(dictSize);
if (dictCapacity != (int)dictSize)
{
Array.Resize(ref dictBuffer, (int)dictSize);
}
return(dictBuffer);
}
public unsafe int Unwrap(ReadOnlySpan <byte> src, Span <byte> dst, bool bufferSizePrecheck = true)
{
if (src.Length == 0)
{
return(0);
}
if (bufferSizePrecheck)
{
if (GetDecompressedSize(src) > (ulong)dst.Length)
{
throw new InsufficientMemoryException(
"Buffer size is less than specified decompressed data size");
}
}
UIntPtr dstSize;
fixed(byte *dstPtr = dst)
fixed(byte *srcPtr = src)
{
if (Options.Ddict == IntPtr.Zero)
{
dstSize = ExternMethods.ZSTD_decompressDCtx(dctx, dstPtr, (UIntPtr)dst.Length, srcPtr,
(UIntPtr)src.Length);
}
else
{
dstSize = ExternMethods.ZSTD_decompress_usingDDict(dctx, dstPtr, (UIntPtr)dst.Length, srcPtr,
(UIntPtr)src.Length, Options.Ddict);
}
}
ReturnValueExtensions.EnsureZstdSuccess(dstSize);
return((int)dstSize);
}
public static int GetCompressBound(int size)
{
return((int)ExternMethods.ZSTD_compressBound((UIntPtr)size));
}
public ZstdCompressor(ZstdCompressionOptions options)
{
Options = options;
cctx = ExternMethods.ZSTD_createCCtx().EnsureZstdSuccess();
}
public static unsafe ulong GetDecompressedSize(ReadOnlySpan <byte> src)
{
fixed(byte *srcPtr = src)
return(ExternMethods.ZSTD_getDecompressedSize(srcPtr, (UIntPtr)src.Length));
}
