private bool AddWordInternal(string word)
{
ConcurrentWordStateMachineState currentState = InitialState;
foreach (var letter in FormatWord(word))
{
if (currentState.LetterDictionary.ContainsKey(letter))
{
currentState = currentState.LetterDictionary[letter];
}
else
{
ConcurrentWordStateMachineState newState = new ConcurrentWordStateMachineState(currentState, letter);
currentState.LetterDictionary[letter] = newState;
currentState = newState;
}
}
if (currentState.IsWordEnd)
{
return(false);
}
else
{
currentState.IsWordEnd = true;
return(true);
}
}
public bool RemoveWord(string word)
{
try
{
StateMachineLock.EnterWriteLock();
ConcurrentWordStateMachineState currentState = InitialState;
foreach (var letter in FormatWord(word))
{
if (currentState.LetterDictionary.ContainsKey(letter))
{
currentState = currentState.LetterDictionary[letter];
}
else
{
return(false);
}
}
if (currentState.LetterDictionary.Count == 0)
{
while (currentState.PreviousState.LetterDictionary.Count == 1)
{
currentState = currentState.PreviousState;
}
currentState.PreviousState.LetterDictionary.Remove(currentState.Letter);
}
else
{
currentState.IsWordEnd = false;
}
return(true);
}
finally
{
StateMachineLock.ExitWriteLock();
}
}
public ConcurrentWordStateMachineState(ConcurrentWordStateMachineState previousState, char letter)
{
this.PreviousState = previousState;
this.LetterDictionary = new Dictionary <char, ConcurrentWordStateMachineState>();
this.Letter = letter;
}
public ConcurrentWordStateMachine()
{
InitialState = new ConcurrentWordStateMachineState(null);
StateMachineLock = new ReaderWriterLockSlim(LockRecursionPolicy.NoRecursion);
}