/// <summary>
/// read data part of input file, writes it to output file decompressed
/// </summary>
/// <param name="Reader"></param>
/// <param name="Writer"></param>
/// <param name="Tree">contains huffman tree</param>
public static void DecompressFile(BinaryReader Reader, BinaryWriter Writer, Huff3TreeBuilder Tree)
{
int size = 4096;
byte[] buffer;
bool empty = true;
uint mask = 1; //to get least significant bit
//we need to know, how many symbols should be in file otherwise we could interpret trailing zeros at the end of file as symbols
ulong remainingSymbols = Tree.NumberOfSymbols;
Node Root = Tree.Root;
Node iterator = Tree.Root;
//read file using buffer
do
{
buffer = Reader.ReadBytes(size);
foreach (byte item in buffer)
{
uint it = (uint)item;
for (int i = 0; i < 8; i++)
{
//get value of the least significant bit
uint curr = it & mask;
// Console.Write("{0} ", curr);
//shift - get rid of bit already taken into account
it = it >> 1;
if (remainingSymbols == 0)
{
//end of file - only trailling zeroes remaining
return;
}
DoStepInTree(ref iterator, curr, Writer, Root, ref remainingSymbols);
}
empty = false;
}
} while (buffer.Length == size);
if (remainingSymbols > 0)
{
Console.WriteLine("File Error");
}
}
static void HuffIII(string[] args)
{
bool opened = Program.Huff3OpenFiles(args, out BinaryReader reader, out BinaryWriter writer);
if (!opened)
{
return;
}
Huff3TreeBuilder b = new Huff3TreeBuilder();
bool success = b.ReadHeaderAndTreeFromBinaryFile(reader);
if (!success)
{
return;
}
Huff3Decompresor.DecompressFile(reader, writer, b);
reader.Close();
writer.Close();
}