public void CreateModel()
{
Number = 3;
Weight = 2;
Left = new DynamicHuffmanTree();
Left.SpecialSymbol = "Esc";
Left.Number = 1;
Left.Weight = 1;
Right = new DynamicHuffmanTree();
Right.SpecialSymbol = "EoF";
Right.Number = 2;
Right.Weight = 1;
}
private DynamicHuffmanTree FindParent(DynamicHuffmanTree Child)
{
if (Left == Child || Right == Child || this == Child)
{
return(this);
}
DynamicHuffmanTree Result = null;
if (Right != null)
{
Result = Right.FindParent(Child);
}
if (Result == null && Left != null)
{
Result = Left.FindParent(Child);
}
return(Result);
}
private DynamicHuffmanTree Find(int NumberToFind)
{
if (Number == NumberToFind)
{
return(this);
}
DynamicHuffmanTree Result = null;
if (Right != null)
{
Result = Right.Find(NumberToFind);
}
if (Result == null && Left != null)
{
Result = Left.Find(NumberToFind);
}
return(Result);
}
private DynamicHuffmanTree Find(string SpecialSymbolToFind)
{
if (SpecialSymbol == SpecialSymbolToFind)
{
return(this);
}
DynamicHuffmanTree Result = null;
if (Right != null)
{
Result = Right.Find(SpecialSymbolToFind);
}
if (Result == null && Left != null)
{
Result = Left.Find(SpecialSymbolToFind);
}
return(Result);
}
public string Encode(Byte?SymbolToEncode)
{
string Code = "";
char a = Convert.ToChar(SymbolToEncode);
DynamicHuffmanTree KeyLeave;
if (SymbolToEncode == null)
{
KeyLeave = Find("EoF");
}
else
{
KeyLeave = Find(SymbolToEncode);
if (KeyLeave == null)
{
Code = DynamicHuffmanTree.ToBinaryString(SymbolToEncode);
KeyLeave = Find("Esc");
}
}
DynamicHuffmanTree Parent = this.FindParent(KeyLeave);
do
{
if (Parent.Left == KeyLeave)
{
Code = "0" + Code;
}
if (Parent.Right == KeyLeave)
{
Code = "1" + Code;
}
KeyLeave = Parent;
Parent = this.FindParent(KeyLeave);
}while (Parent != KeyLeave);
Rebuild(SymbolToEncode);
return(Code);
}
private void Rebuild(Byte?SymbolToEncode)
{
DynamicHuffmanTree CurrentVertex = Find(SymbolToEncode);
if (CurrentVertex == null)
{
DynamicHuffmanTree NewVertex = new DynamicHuffmanTree();
DynamicHuffmanTree LastVertex = Find(1);
DynamicHuffmanTree LastVertexParent = FindParent(LastVertex);
DynamicHuffmanTree VertexWithSymbol = new DynamicHuffmanTree();
VertexWithSymbol.Symbol = SymbolToEncode;
VertexWithSymbol.Weight = 1;
NewVertex.Weight = LastVertex.Weight + VertexWithSymbol.Weight;
LastVertexParent.Left = NewVertex;
NewVertex.Left = VertexWithSymbol;
NewVertex.Right = LastVertex;
CurrentVertex = NewVertex;
ReNumber();
}
else
{
CurrentVertex.Weight++;
}
while (CurrentVertex != this)
{
int Number = CurrentVertex.Number;
while (CurrentVertex.Weight == Find(Number + 1).Weight + 1)
{
Number++;
}
if (Number != CurrentVertex.Number)
{
DynamicHuffmanTree VertexForChange;
VertexForChange = Find(Number);
if (FindParent(VertexForChange) != FindParent(CurrentVertex))
{
DynamicHuffmanTree Parent1 = FindParent(VertexForChange);
DynamicHuffmanTree Parent2 = FindParent(CurrentVertex);
if (Parent1.Left == VertexForChange)
{
Parent1.Left = CurrentVertex;
}
if (Parent1.Right == VertexForChange)
{
Parent1.Right = CurrentVertex;
}
if (Parent2.Left == CurrentVertex)
{
Parent2.Left = VertexForChange;
}
if (Parent2.Right == CurrentVertex)
{
Parent2.Right = VertexForChange;
}
}
else
{
DynamicHuffmanTree Parent = FindParent(VertexForChange);
if (Parent.Left == VertexForChange)
{
Parent.Left = CurrentVertex;
Parent.Right = VertexForChange;
}
if (Parent.Left == CurrentVertex)
{
Parent.Left = VertexForChange;
Parent.Right = CurrentVertex;
}
}
}
CurrentVertex = FindParent(CurrentVertex);
CurrentVertex.Weight++;
ReNumber();
}
}
public static double Encode(string file_name)
{
bool opened = false;
BinaryWriter output_file = null;
try
{
_source_file = new BinaryReader(File.OpenRead(file_name));
output_file = new BinaryWriter(File.Create($@"{System.Windows.Forms.Application.StartupPath}\output.dynhuf"));
opened = true;
}
catch (Exception e)
{
System.Windows.Forms.MessageBox.Show(e.Message);
}
if (opened)
{
DynamicHuffmanTree encoding_model = new DynamicHuffmanTree();
encoding_model.CreateModel();
bool end_of_file = false;
Byte symbol = 0;
string code = "";
string buffer = "";
char[] CharTypeBuffer;
FileInfo file_info = new FileInfo(file_name);
CharTypeBuffer = (file_info.Extension.Substring(1, file_info.Extension.Length - 1) + ".").ToCharArray();
output_file.Write(CharTypeBuffer);
while (!end_of_file)
{
try
{
symbol = _source_file.ReadByte();
}
catch
{
end_of_file = true;
}
if (!end_of_file)
{
code = encoding_model.Encode(symbol);
}
else
{
code = encoding_model.Encode(null);
}
code = buffer + code;
buffer = code.Substring(code.Length - (code.Length % 8), (code.Length) - (code.Length - (code.Length % 8)));
code = code.Remove(code.Length - (code.Length % 8), (code.Length) - (code.Length - (code.Length % 8)));
while (code != "")
{
output_file.Write(DynamicHuffmanTree.ToByte(code.Substring(0, 8)));
code = code.Remove(0, 8);
}
if (end_of_file)
{
while (buffer.Length != 8)
{
buffer += "0";
}
output_file.Write(DynamicHuffmanTree.ToByte(buffer));
}
}
_source_file.Close();
output_file.Close();
BinaryReader ResultFile = new BinaryReader(File.OpenRead($@"{System.Windows.Forms.Application.StartupPath}\output.dynhuf"));
BinaryReader BaseFile = new BinaryReader(File.OpenRead(file_name));
double result = (double)ResultFile.BaseStream.Length / (double)BaseFile.BaseStream.Length;
ResultFile.Close();
BaseFile.Close();
return(result);
}
return(-1);
}