private static void roundTrip(HuffmanEncoder encoder, HuffmanDecoder decoder, byte[] buf)
{
using(var baos = new MemoryStream()) {
using(var dos = new BinaryWriter(baos)) {
encoder.Encode(dos, buf);
var actualBytes = decoder.Decode(baos.ToArray());
Assert.IsTrue(buf.SequenceEqual(actualBytes));
}
}
}
private static string DecodeWithHuffman(string dictFilename, byte[] bytes)
{
var serializedDict = File.ReadAllText(dictFilename);
var rates = serializedDict.Split('操').Select(x =>
{
var chr = x[0];
var rate = int.Parse(x.Substring(1, x.Length - 1));
return(new { chr, rate });
}).ToDictionary(x => x.chr, x => x.rate);
var huffmanTree = new HuffmanDecoder();
huffmanTree.BuildWithRates(rates);
return(huffmanTree.Decode(new BitArray(bytes)));
}
public void Decode_ThreeSymbols_TwoAreRight()
{
//given
var tree = MockHuffmanTreeBuilder.Build('c', '#', 'x', 'a');
var decoder = new HuffmanDecoder <char>(tree);
var input = new MockDecoderInput(new List <int> {
0, 1, 1, 1, 0
});
var output = new MockDecoderOutput(new List <char> {
'c', 'a', 'x'
});
//when
decoder.Decode(input, output);
//then
output.AssertCorrectOutput();
}
public void Decode_FourSymbols_DeepTree()
{
//given
var tree = MockHuffmanTreeBuilder.Build('a', '#', 'b', '#', 'c', 'd');
var decoder = new HuffmanDecoder <char>(tree);
var input = new MockDecoderInput(new List <int> {
0, 1, 0, 1, 1, 0, 1, 1, 1
});
var output = new MockDecoderOutput(new List <char> {
'a', 'b', 'c', 'd'
});
//when
decoder.Decode(input, output);
//then
output.AssertCorrectOutput();
}
public override object Decode(Stream stream)
{
byte num = stream.CreateSuitableBinaryReader().ReadByte();
byte[] numArray;
try
{
numArray = HuffmanDecoder.Decode(stream);
}
catch (Exception ex)
{
throw new CodecException("Unable to decode", ex);
}
byte[] buffer = numArray != null ? new byte[numArray.Length + 1] : throw new CodecException("Unable to decode");
buffer[0] = num;
Buffer.BlockCopy(numArray, 0, buffer, 1, numArray.Length);
using (MemoryStream memoryStream = new MemoryStream(buffer))
return(base.Decode(memoryStream));
}