public TreeWalker(HuffmanTreeBase tree, IDecodingInputStream input, IDecodingOutputStream output, long seqLength)
{
this.tree = tree;
this.input = input;
this.output = output;
this.seqLength = seqLength;
}
public CodingTable BuildCodingTable(HuffmanTreeBase huffmanTree)
{
Guard.IsNotNull(huffmanTree, nameof(huffmanTree));
TreeVisitor visitor = new TreeVisitor();
huffmanTree.DoPOT(visitor);
return(visitor.CodingTable);
}
const int ChunkSize = 128 * 1024; // 128Kb throttling
public EncodingToken CreateEncodingToken(IEncodingInputStream inputStream, CancellationToken cancellationToken)
{
Guard.IsNotNull(inputStream, nameof(inputStream));
WeightsTable weightsTable = BuildWeightsTable(inputStream, cancellationToken);
HuffmanTreeBase huffmanTree = BuildHuffmanTree(weightsTable);
CodingTable codingTable = BuildCodingTable(huffmanTree);
return(new EncodingToken(weightsTable, huffmanTree, codingTable));
}
public void Decode(IDecodingInputStream inputStream, HuffmanTreeBase tree, IDecodingOutputStream outputStream, long sequenceLength, CancellationToken cancellationToken, IProgressHandler progress)
{
Guard.IsNotNull(inputStream, nameof(inputStream));
Guard.IsNotNull(tree, nameof(tree));
Guard.IsNotNull(outputStream, nameof(outputStream));
Guard.IsNotNegative(sequenceLength, nameof(sequenceLength));
const int chunkSize = 0x20000 * 8; // 128Kb
long progressValue = progress?.State.CastTo <CodingProgressState>()?.Value ?? 0;
long streamPosition = inputStream.Position;
TreeWalker walker = new TreeWalker(tree, inputStream, outputStream, sequenceLength);
while (!walker.Exhausted && !inputStream.IsEmpty)
{
if (!tree.Walk(walker))
{
throw new ArgumentException();
}
// Throttling
progressValue += inputStream.Position - streamPosition;
streamPosition = inputStream.Position;
if (progressValue >= chunkSize)
{
cancellationToken.ThrowIfCancellationRequested();
progress?.Report(progressValue / 8, outputStream.Path);
progressValue %= 8;
}
}
if (progress != null)
{
CodingProgressState progressState = (CodingProgressState)progress.State ?? new CodingProgressState();
progress.State = progressState.WithValue(progressValue);
}
}
public EncodingToken(WeightsTable weightsTable, HuffmanTreeBase huffmanTree, CodingTable codingTable)
{
CodingTable = codingTable;
WeightsTable = weightsTable;
HuffmanTree = huffmanTree;
}
