internal Deflater(CompressionLevel compressionLevel, int windowBits)
{
Debug.Assert(windowBits >= minWindowBits && windowBits <= maxWindowBits);
ZLibNative.CompressionLevel zlibCompressionLevel;
int memLevel;
switch (compressionLevel)
{
// See the note in ZLibNative.CompressionLevel for the recommended combinations.
case CompressionLevel.Optimal:
zlibCompressionLevel = ZLibNative.CompressionLevel.DefaultCompression;
memLevel = ZLibNative.Deflate_DefaultMemLevel;
break;
case CompressionLevel.Fastest:
zlibCompressionLevel = ZLibNative.CompressionLevel.BestSpeed;
memLevel = ZLibNative.Deflate_DefaultMemLevel;
break;
case CompressionLevel.NoCompression:
zlibCompressionLevel = ZLibNative.CompressionLevel.NoCompression;
memLevel = ZLibNative.Deflate_NoCompressionMemLevel;
break;
case CompressionLevel.SmallestSize:
zlibCompressionLevel = ZLibNative.CompressionLevel.BestCompression;
memLevel = ZLibNative.Deflate_DefaultMemLevel;
break;
default:
throw new ArgumentOutOfRangeException(nameof(compressionLevel));
}
ZLibNative.CompressionStrategy strategy = ZLibNative.CompressionStrategy.DefaultStrategy;
ZLibNative.ZLibStreamHandle?zlibStream = null;
ZErrorCode errC;
try
{
errC = ZLibNative.CreateZLibStreamForDeflate(out zlibStream, zlibCompressionLevel,
windowBits, memLevel, strategy);
}
catch (Exception cause)
{
zlibStream?.Dispose();
throw new ZLibException(SR.ZLibErrorDLLLoadError, cause);
}
_zlibStream = zlibStream;
switch (errC)
{
case ZErrorCode.Ok:
return;
case ZErrorCode.MemError:
throw new ZLibException(SR.ZLibErrorNotEnoughMemory, "deflateInit2_", (int)errC, _zlibStream.GetErrorMessage());
case ZErrorCode.VersionError:
throw new ZLibException(SR.ZLibErrorVersionMismatch, "deflateInit2_", (int)errC, _zlibStream.GetErrorMessage());
case ZErrorCode.StreamError:
throw new ZLibException(SR.ZLibErrorIncorrectInitParameters, "deflateInit2_", (int)errC, _zlibStream.GetErrorMessage());
default:
throw new ZLibException(SR.ZLibErrorUnexpected, "deflateInit2_", (int)errC, _zlibStream.GetErrorMessage());
}
}
