public uint FastStreamEncoder(int blockLength, int sourceLength, int extraBlocks = 0)
{
sourceLength = Mem.RoundUp(sourceLength, blockLength);
var targetLength = 2 * sourceLength;
var source = new byte[sourceLength];
var target = new byte[targetLength];
Lorem.Fill(source, 0, source.Length);
using (var encoder = new LZ4FastEncoder(blockLength, extraBlocks))
{
var sourceP = 0;
var targetP = 0;
while (sourceP < sourceLength && targetP < targetLength)
{
encoder.TopupAndEncode(
source, sourceP, Math.Min(blockLength, sourceLength - sourceP),
target, targetP, targetLength - targetP,
true, false,
out var loaded,
out var encoded);
sourceP += loaded;
targetP += encoded;
}
return(Tools.Adler32(target, 0, targetP));
}
}
private static byte[] Encode(byte[] input, int topupSize, int blockSize, int extraBlocks)
{
using (var outputStream = new MemoryStream())
using (var inputStream = new MemoryStream(input))
{
using (var inputReader = new BinaryReader(inputStream, Encoding.UTF8, false))
using (var outputWriter = new BinaryWriter(outputStream, Encoding.UTF8, true))
using (var encoder = new LZ4FastEncoder(blockSize, extraBlocks))
{
var inputBuffer = new byte[topupSize];
var outputBuffer = new byte[LZ4Codec.MaximumOutputSize(encoder.BlockSize)];
while (true)
{
var bytes = inputReader.Read(inputBuffer, 0, inputBuffer.Length);
if (bytes == 0)
{
Flush(outputWriter, encoder, outputBuffer);
outputWriter.Write(-1);
break;
}
Write(outputWriter, encoder, inputBuffer, bytes, outputBuffer);
}
}
return(outputStream.ToArray());
}
}
public void HighEntropyRepeated()
{
var random = new Random(0);
var encoder = new LZ4FastEncoder(256);
var source = new byte[256];
random.NextBytes(source);
var target = new byte[1024];
Assert.Equal(256, encoder.Topup(source, 0, 256));
Assert.Equal(-256, encoder.Encode(target, 0, 1024, true));
Assert.Equal(256, encoder.Topup(source, 0, 256));
Assert.True(encoder.Encode(target, 0, 1024, true) < 32);
}
