public void Compress(string path)
{
writer = new CompressedFileWriter(path + ".lz");
bitBuffer = new List <bool>();
dictionary = new StringBuilder();
phrase = string.Empty;
using (var streamReader = new StreamReader(path))
{
var chars = new char[CHAR_BLOCK_LENGTH];
while (!streamReader.EndOfStream)
{
var readChars = streamReader.ReadBlock(chars, 0, CHAR_BLOCK_LENGTH);
var dataToBeEncoded = new StringBuilder(new string(chars.Take(readChars).ToArray()));
compressBlock(dataToBeEncoded);
}
writer.WriteBlock(bitBuffer);
}
writer.Close();
}
private void compressBlock(StringBuilder dataToBeEncoded)
{
while (dataToBeEncoded.Length > 0)
{
var indexInData = 0;
var offset = 2047; // nastaveny offset na 2047, polovica CHAR_BLOCK_LENGTH
var actualDictionary = dictionary.ToString();
phrase += dataToBeEncoded[indexInData];
var indexOfPhrase = actualDictionary.IndexOf(phrase, 0);
while (indexOfPhrase > -1 && indexInData + 1 < dataToBeEncoded.Length)
{
offset = indexOfPhrase;
phrase += dataToBeEncoded[++indexInData];
indexOfPhrase = actualDictionary.IndexOf(phrase, indexOfPhrase);
}
var compressedPhrase = compressPhrase((ushort)offset, (ushort)(phrase.Length - 1), phrase.Last());
if (bitBuffer.Count + compressedPhrase.Count < BIT_BLOCK_LENGTH)
{
bitBuffer.AddRange(compressedPhrase);
}
else
{
var missingBitsCount = BIT_BLOCK_LENGTH - bitBuffer.Count;
bitBuffer.AddRange(compressedPhrase.GetRange(0, missingBitsCount));
writer.WriteBlock(bitBuffer);
bitBuffer = compressedPhrase.GetRange(missingBitsCount, compressedPhrase.Count - missingBitsCount);
}
dictionary.Append(dataToBeEncoded.ToString(0, phrase.Length));
if (dictionary.Length > DICTIONARY_SIZE)
{
dictionary.Remove(DICTIONARY_SIZE, dictionary.Length - DICTIONARY_SIZE);
}
dataToBeEncoded.Remove(0, phrase.Length);
phrase = string.Empty;
}
}
