private void GenerateButton_Click(object sender, RoutedEventArgs e)
{
var listRand = new ListRand();
// Let's have some fun with TPL
var nums = Enumerable.Range(0, NODES_COUNT-1).ToArray();
// Just a balanced partitioner
var partitioner = Partitioner.Create(nums, true);
var nodes = partitioner.AsParallel().Select(i =>
{
var newNode = new ListNode
{
Id = Guid.NewGuid(),
Data = string.Format("Node{0} Data", i)
};
return newNode;
}).ToList();
var rand = new Random(Environment.TickCount);
ListNode previous = null;
foreach (var node in nodes)
{
node.Previous = previous;
node.Random = nodes[rand.Next(0, nodes.Count)];
if (previous != null)
{
previous.Next = node;
}
previous = node;
}
listRand.Count = nodes.Count;
listRand.Head = nodes.First();
listRand.Tail = nodes.Last();
_lastListRand = listRand;
PrintList(listRand, GeneratedListTextBox);
}
// Changed to just a stream to make it possible to deserialize from memory stream
public void Deserialize(Stream stream)
{
// Again, we do not going to manage the stream here since it was initialized somewhere outside.
// The only we can do here is to catch the errors while reading to rethrow with meaningful message.
var reader = new StreamReader(stream);
var serializedString = reader.ReadToEnd();
// Just a simple regex matching the pattern like
//'Id:a5c2e13e-85af-40b8-9633-4c9e1c001f62;Prev:00000000-0000-0000-0000-000000000000;Next:59bee4b3-645c-4184-9502-508d5d23096d;Rand:59bee4b3-645c-4184-9502-508d5d23096d;Data:Node1 Data'
var regex = new Regex(@"((Id:[;:\w\d\s-]+?);[\s])", RegexOptions.Multiline);
var nodeStrings = new List<string>();
var matches = regex.Matches(serializedString).OfType<Match>();
foreach (var match in matches)
{
// Groups[0] - whole match; Groups[1] - outer group (equal to whole match; seems redundant); Groups[2] - w/o trailing ';' and linebreak
var matchWithoutTrailingSemicolon = match.Groups[2].Value;
nodeStrings.Add(matchWithoutTrailingSemicolon);
}
var nodes = new List<ListNode>(nodeStrings.Count);
// Creating the cross nodes references Dixtionary. Using the Tuple for simplicity
// Assuming the Tuple of Previous; Next; Random node ids
var references = new Dictionary<Guid, Tuple<Guid, Guid, Guid>>();
// Just a simple Regex to extract field values
var idRegex = new Regex("Id:(.+?);");
var prevRegex = new Regex("Prev:(.+?);");
var nextRegex = new Regex("Next:(.+?);");
var randRegex = new Regex("Rand:(.+?);");
var dataRegex = new Regex("Data:(.+?)$");
nodeStrings.ForEach(ns =>
{
// I know it is BAD to not check IsMatch and Groups count
// It is not needed in case of such simple task. Just ommiting the flood of If... Else.
var id = Guid.Parse(idRegex.Match(ns).Groups[1].Value);
var prevId = Guid.Parse(prevRegex.Match(ns).Groups[1].Value);
var nextId = Guid.Parse(nextRegex.Match(ns).Groups[1].Value);
var randId = Guid.Parse(randRegex.Match(ns).Groups[1].Value);
var data = dataRegex.Match(ns).Groups[1].Value;
nodes.Add(new ListNode { Id = id, Data = data });
references.Add(id, new Tuple<Guid, Guid, Guid>(prevId, nextId, randId));
});
nodes.ForEach(n =>
{
// There should be a value with given Id in Dictionary
// For safety we can add a check and skip if there no value in Dictionary
var reference = references[n.Id];
// If Previous Id is Guid.Empty, then this node is a head and Previous reference should be void
if (reference.Item1 != Guid.Empty)
{
n.Previous = nodes.Single(o => o.Id == reference.Item1);
}
else
{
// Assign the Head reference here
this.Head = n;
}
// If Next Id is Guid.Empty, then this node is a Tail and Previous reference should be void
if (reference.Item2 != Guid.Empty)
{
n.Next = nodes.Single(o => o.Id == reference.Item2);
}
else
{
// Assign the Tail reference here
this.Tail = n;
}
n.Random = nodes.Single(o => o.Id == reference.Item3);
});
this.Count = nodes.Count;
}
