private void Write(string inputFile, string outputFile)
{
using (BitWriter bitWriter = new BitWriter(outputFile))
{
//header
WriteAlocationMap(bitWriter);
WriteCharFrequencyOn4Bytes(bitWriter);
FileInfo file = new FileInfo(inputFile);
int numberOfBits = 8 * (int)file.Length;
using (BitReader bitReader = new BitReader(inputFile))
{
while (numberOfBits > 0)
{
int character = bitReader.readNBits(8);
bitWriter.WriteNBits(_charCode[character], _codeLength[character]);
numberOfBits -= 8;
}
bitWriter.WriteNBits(0, 7);
}
}
}
private void Encode(string s, BitWriter bitWriter)
{
bitWriter.WriteNBits(_symbolList.IndexOf(s.ToString()), _index);
}
public void Compress(string inputFile, string outputFile)
{
FileInfo file = new FileInfo(inputFile);
buffer = new byte[file.Length];
int index = 0;
using (BitReader bitReader = new BitReader(inputFile))
using (BitWriter bitWriter = new BitWriter(outputFile))
{
FillBuffer(bitReader);
int character = buffer[index];
int position = 0;
int length = 0;
//first token
WriteToken(bitWriter, position, length, character);
_slidingWindow.Add(character);
index++;
character = buffer[index];
length = 0;
while (index < buffer.Length)
{
int i = 0;
string prevChar = null;
while (i < _searchBufferMaxLength)
{
if (i < _slidingWindow.Count)
{
break;
}
int lookAheadIndex = index - i - 1;
if (buffer[lookAheadIndex] == character)
{
//vezi cat de lunga ii secventa de potrivire
prevChar = character.ToString();
int j = lookAheadIndex;
while (j < _lookAheadBufferMaxLength + i)
{
if (j > buffer.Length)
{
break;
}
character = buffer[lookAheadIndex];
}
}
else
{
i++;
}
}
}
/*******************************************************************************/
//first token
WriteToken(bitWriter, position, length, character);
_slidingWindow.Add(character);
character = bitReader.readNBits(8);
position = 0;
if (_slidingWindow[0] == character)
{
length = 1;
_slidingWindow.Add(character);
character = bitReader.readNBits(8);
}
else
{
length = 0;
}
//second token
WriteToken(bitWriter, position, length, character);
_slidingWindow.Add(character);
character = bitReader.readNBits(8);
if (_slidingWindow[1] == character)
{
position = 0;
_slidingWindow.Add(character);
character = bitReader.readNBits(8);
if (_slidingWindow[2] == character)
{
}
else
{
}
}
else
if (_slidingWindow[0] == character)
{
position = 1;
_slidingWindow.Add(character);
character = bitReader.readNBits(8);
if (_slidingWindow[1] == character)
{
}
else
{
length = 1;
}
}
//third token
WriteToken(bitWriter, position, length, character);
}
}
private void DecodeAndWrite(BitReader bitReader, int fileLength, TreeNode <KeyValuePair <int, int> > huffmanTree, BitWriter bitWriter)
{
TreeNode <KeyValuePair <int, int> > currentNode;
for (int i = 0; i < fileLength; i++)
{
currentNode = huffmanTree;
while (!currentNode.IsLeaf())
{
int bit = bitReader.readBit();
currentNode = bit == 0 ? currentNode.leftChild : currentNode.rightChild;
}
//scrie caracterul
int decodedChar = currentNode.value.Key;
bitWriter.WriteNBits(decodedChar, 8);
}
}
private void WriteToken(BitWriter bitWriter, int position, int length, int character)
{
bitWriter.WriteNBits(position, _p);
bitWriter.WriteNBits(length, _l);
bitWriter.WriteNBits(character, 8);
}