public void ContainsIndexReturnsTrueForValuesFrom0To255()
{
var allAreContained = true;
var lzWDictionary = new LzWDictionary(258, OnFullDictionaryOption.Empty);
for (uint i = 0; i < 256; i++)
{
if (!lzWDictionary.ContainsIndex(i))
{
allAreContained = false;
break;
}
}
Assert.IsTrue(allAreContained);
}
public void DecodeFile(IFileReader fileReader, IFileWriter fileWriter)
{
if (fileReader == null)
{
throw new ArgumentNullException(nameof(fileReader));
}
if (fileWriter == null)
{
throw new ArgumentNullException(nameof(fileWriter));
}
InterpretHeader(fileReader);
var firstIndex = fileReader.ReadBits(numberOfBitsForIndex);
var firstString = lzWDictionary.GetStringByIndex(firstIndex);
firstString.WriteToFile(fileWriter);
var lastString = firstString;
while (!fileReader.ReachedEndOfFile && fileReader.BitsLeft >= numberOfBitsForIndex)
{
var currentIndex = fileReader.ReadBits(numberOfBitsForIndex);
string currentString;
if (lzWDictionary.ContainsIndex(currentIndex))
{
currentString = lzWDictionary.GetStringByIndex(currentIndex);
var dictionaryNewString = lastString + currentString[0];
lzWDictionary.Add(dictionaryNewString);
}
else
{
var dictionaryNewString = lastString + lastString[0];
lzWDictionary.Add(dictionaryNewString);
currentString = lzWDictionary.GetStringByIndex(currentIndex);
}
currentString.WriteToFile(fileWriter);
lastString = currentString;
}
}