protected void ParseDictionary(string[] dictionary)
{
_root = new HuffmanTreeNode();
HuffmanTreeNode current;
foreach (string line in dictionary)
{
int splitIndex = line.LastIndexOf("=");
string entry = line.Substring(0, splitIndex);
string path = line.Substring(splitIndex + 1, line.Length - splitIndex - 1);
current = _root;
foreach (char c in path)
{
if (c == '1')
{
if (current.P1 == null)
{
current.P1 = new HuffmanTreeNode();
}
current = current.P1;
}
else
{
if (current.P0 == null)
{
current.P0 = new HuffmanTreeNode();
}
current = current.P0;
}
}
current.Value = entry;
}
}
public static HuffmanTreeNode CreateTree(string[] dictionary)
{
HuffmanTreeNode root = new HuffmanTreeNode();
HuffmanTreeNode current;
foreach (string line in dictionary)
{
int splitIndex = line.LastIndexOf("=");
string entry = line.Substring(0, splitIndex);
string path = line.Substring(splitIndex + 1, line.Length - splitIndex - 1);
current = root;
for (int t = 0; t < path.Length; t++)
{
if (path[t] == '1')
{
if (current.P1 == null)
{
current.P1 = new HuffmanTreeNode();
}
current = current.P1;
}
else
{
if (current.P0 == null)
{
current.P0 = new HuffmanTreeNode();
}
current = current.P0;
}
}
current.Value = entry;
}
return(root);
}
public void Clear()
{
if (P1 != null)
{
P1 = null;
P0 = null;
}
}
public string Decode(byte[] data, int offset, int length)
{
StringBuilder decodedText = new StringBuilder();
bool codeError = false;
bool isFound = false;
int lastIndex = offset;
byte lastMask = 0;
HuffmanTreeNode current = _root;
byte currentByte;
byte mask;
for (int i = offset; i < length + offset; i++)
{
currentByte = data[i];
mask = 0x80;
if (i == offset)
{
if ((currentByte & 0x20) == 1)
{
//showatend = true;
}
mask = 0x20;
lastIndex = i;
lastMask = mask;
}
while (true)
{
if (isFound)
{
lastIndex = i;
lastMask = mask;
isFound = false;
}
if (!codeError)
{
HuffmanTreeNode next = (currentByte & mask) == 0 ? current.P0 : current.P1;
if (next != null)
{
current = next;
if (!string.IsNullOrEmpty(current.Value))
{
if (current.Value != "!!!")
{
decodedText.Append(current.Value);
}
current = _root;
isFound = true;
}
}
else
{
i = lastIndex;
currentByte = data[lastIndex];
mask = lastMask;
codeError = true;
continue;
}
}
mask = (byte)(mask >> 1);
if (mask == 0)
{
break;
}
}
}
return(decodedText.ToString());
}
