/// <summary>
/// Runs a search.
/// </summary>
/// <param name="startState">The state that the search will start from</param>
/// <param name="maxDepth">The search will be terminated after maxDepth</param>
/// <param name="cancellationToken">Used to cancel the search</param>
public SearchResult Search(IDeterministicState startState, int maxDepth, CancellationToken cancellationToken)
{
if (StateDefinesDepth && CacheMode != CacheMode.NoCache && CacheKeyType != CacheKeyType.StateOnly)
{
throw new MinMaxSearchException($"If {nameof(StateDefinesDepth)} the cache key should be of type {CacheKeyType.StateOnly}");
}
if (!startState.GetNeighbors().Any())
{
throw new NoNeighborsException("start state has no neighbors " + startState);
}
if (maxDepth < 1)
{
throw new ArgumentException($"{nameof(maxDepth)} must be at least 1. Was {maxDepth}");
}
if (SkipEvaluationForFirstNodeSingleNeighbor && startState.GetNeighbors().Count() == 1)
{
return(new SearchResult(0, startState, true, true, false));
}
var searchContext = new SearchContext(maxDepth, 0, cancellationToken);
var searchWorker = new SearchWorker(CreateSearchOptions(), GetThreadManager(maxDepth), cacheManagerFactory());
var stopwatch = new Stopwatch();
stopwatch.Start();
var result = searchWorker.Evaluate(startState, searchContext);
stopwatch.Stop();
result.StateSequence.Reverse();
result.StateSequence.RemoveAt(0); // Removing the top node will make the result "nicer"
return(new SearchResult(result, stopwatch.Elapsed, maxDepth, !cancellationToken.IsCancellationRequested));
}
private Task <SearchResult> Evaluate(IDeterministicState startState, SearchContext searchContext,
IDictionary <IState, double> storedStates, IState state)
{
var taskResult = storedStates != null && storedStates.ContainsKey(state)
? Task.FromResult(new SearchResult(storedStates[state], state))
: threadManager.Invoke(() =>
{
var actualStartState = startState is ProbablisticStateWrapper wrapper
? (IState)wrapper.InnerState
: startState;
return(searchWorker.Evaluate(state, searchContext.CloneAndAddState(actualStartState)));
}, searchContext.CurrentDepth);
return(taskResult);
}