private static DataRecord GetData(byte[] input, string filename, CompressType compress) {
if (compress == CompressType.Nothing) {
return new DataRecord() { Data = input };
}
if (compress == CompressType.ByExtension && _noCompressExt.Contains(System.IO.Path.GetExtension(filename))) {
return new DataRecord() { Data = input };
}
var cdata = new System.IO.MemoryStream();
//Lzs.Encode(new System.IO.MemoryStream(input), cdata);
byte[] lprops;
using (var lzma = new SharpCompress.Compressors.LZMA.LzmaStream(new SharpCompress.Compressors.LZMA.LzmaEncoderProperties(), false, cdata)) {
lzma.Write(input, 0, input.Length);
lprops = lzma.Properties;
}
if (/*compress == CompressType.ByContent &&*/ (cdata.Length + lprops.Length + 8) > (input.Length * 10 / 8)) {
return new DataRecord() { Data = input };
}
byte[] data = new byte[cdata.Length + lprops.Length + 8];
Array.Copy(BitConverter.GetBytes(input.Length), data, 4);
Array.Copy(BitConverter.GetBytes(lprops.Length), 0, data, 4, 4);
Array.Copy(lprops, 0, data, 8, lprops.Length);
cdata.Position = 0;
cdata.Read(data, lprops.Length + 8, (int)cdata.Length);
return new DataRecord() { Data = data, Compressed = true };
}
/// <summary>
/// Compresses the specified data.
/// </summary>
/// <param name="data">The data.</param>
protected byte[] Compress(byte[] data)
{
using var output = new MemoryStream();
// compress data
var encoderProperties = new SharpCompress.Compressors.LZMA.LzmaEncoderProperties(false, this.LzmaEncoderDictionarySize);
using (var compressor = new SharpCompress.Compressors.LZMA.LzmaStream(encoderProperties, false, output))
{
// compressor flushes to output stream at dispose
compressor.Write(data, 0, data.Length);
}
// return the compressed data
return(output.ToArray());
}
