private async Task ExtractFileAsync(Stream input, ArchivedFile file, string folder, CancellationTokenSource tokenSource, ProgressArgs args)
{
var root = huffman.BuildTree(file.Codes);
using (var output = new FileStream(Path.Combine(folder, file.Name), FileMode.Create, FileAccess.Write, FileShare.None))
{
input.Seek(file.Offset, SeekOrigin.Begin);
await huffman.DecompressAsync(input, output, file.BitsLength, root, tokenSource, this, args);
}
}
public async Task CreateAsync(string[] inputFiles, Stream output, CancellationTokenSource tokenSource)
{
if (inputFiles == null || inputFiles.Length == 0)
{
throw new ArgumentNullException("inputFile");
}
if (output == null)
{
throw new ArgumentNullException("output");
}
await Task.Run(async() =>
{
var args = new ProgressArgs
{
TotalFiles = inputFiles.Length
};
OnReport(args);
var token = tokenSource.Token;
token.ThrowIfCancellationRequested();
using (var bw = new BinaryWriter(output, new UTF8Encoding(), true))
{
var archive = new Archive();
var allCodes = new IEnumerable <SymbolCode> [inputFiles.Length];
var beginPosition = output.Position;
bw.Seek(4, SeekOrigin.Current);
for (int i = 0; i < inputFiles.Length; i++)
{
token.ThrowIfCancellationRequested();
var inputFile = inputFiles[i];
using (var input = File.OpenRead(inputFile))
{
var codes = huffman.GetCodes(input).ToArray();
allCodes[i] = codes;
var originalSize = new FileInfo(inputFile).Length;
var file = new ArchivedFile(Path.GetFileName(inputFile), originalSize, 0, 0, codes);
bw.Write(file.Name);
bw.Write(file.OriginalSize);
file.InfoPosition = output.Position;
bw.Seek(16, SeekOrigin.Current);
var codesPosition = output.Position;
bw.Seek(2, SeekOrigin.Current);
short codesCount = 0;
for (int j = 0; j < codes.Length; j++)
{
if (codes[j] != null)
{
bw.Write((byte)j);
bw.Write(codes[j].Bits);
bw.Write(codes[j].Length);
codesCount++;
}
}
var originalPosition = output.Position;
output.Position = codesPosition;
bw.Write(codesCount);
output.Position = originalPosition;
archive.Add(file);
}
}
args.TotalSize = archive.OriginalSize;
OnReport(args);
for (int i = 0; i < inputFiles.Length; i++)
{
token.ThrowIfCancellationRequested();
args.CurrentFile = i + 1;
OnReport(args);
var inputFile = inputFiles[i];
using (var input = File.OpenRead(inputFile))
{
var codes = allCodes[i];
var file = archive[i];
var offset = output.Position;
var bitsLength = await huffman.CompressAsync(input, output, codes, tokenSource, this, args);
var compressedPosition = output.Position;
var lastArchive = archive.LastOrDefault();
file.BitsLength = bitsLength;
file.Offset = offset;
output.Position = file.InfoPosition;
bw.Write(file.BitsLength);
bw.Write(file.Offset);
output.Position = compressedPosition;
}
}
var endPosition = output.Position;
output.Position = beginPosition;
bw.Write(archive.FilesCount);
output.Position = endPosition;
}
}, tokenSource.Token);
}
