private static void RegisterNeighbourContext(HttpListenerContext http_ctx)
{
Guid otherGuid; string otherHostname; int otherPort;
using (var bodyReader = new StreamReader(http_ctx.Request.InputStream, http_ctx.Request.ContentEncoding ?? Encoding.ASCII))
{
otherGuid = Guid.Parse(bodyReader.ReadLine());
otherHostname = bodyReader.ReadLine();
otherPort = int.Parse(bodyReader.ReadLine());
}
if (nodeGuid.CompareTo(otherGuid) < 0)
outgoingNodeConnections[otherGuid] = new NetworkNode { Hostname = otherHostname, Port = otherPort };
else
incomingNodeConnections[otherGuid] = new NetworkNode { Hostname = otherHostname, Port = otherPort };
var respBodyString = GetNodeSpecString(http_ctx);
var repsBodyData = Encoding.ASCII.GetBytes(respBodyString);
http_ctx.Response.StatusCode = (int)HttpStatusCode.OK;
http_ctx.Response.ContentType = MediaTypeNames.Text.Plain;
http_ctx.Response.ContentEncoding = Encoding.ASCII;
http_ctx.Response.Close(repsBodyData, willBlock: false);
}
private static async Task ExchangeWithNode(Uri otherNodeUri, byte[] nodeSpecData, string contentType)
{
var req = WebRequest.Create(new Uri(otherNodeUri, "/registerNeighbour")) as HttpWebRequest;
req.Method = WebRequestMethods.Http.Post;
req.ContentType = contentType;
req.ContentLength = nodeSpecData.Length;
using (var reqStream = await req.GetRequestStreamAsync())
{
await reqStream.WriteAsync(nodeSpecData, 0, nodeSpecData.Length);
await reqStream.FlushAsync();
}
Guid otherGuid; string otherHostname; int otherPort;
using (var resp = await req.GetResponseAsync() as HttpWebResponse)
{
var respEncoding = string.IsNullOrWhiteSpace(resp.ContentEncoding) ? Encoding.ASCII : Encoding.GetEncoding(resp.ContentEncoding);
using (var respReader = new StreamReader(resp.GetResponseStream(), respEncoding))
{
otherGuid = Guid.Parse(await respReader.ReadLineAsync());
otherHostname = await respReader.ReadLineAsync();
otherPort = int.Parse(await respReader.ReadLineAsync());
}
}
if (nodeGuid.CompareTo(otherGuid) < 0)
outgoingNodeConnections[otherGuid] = new NetworkNode { Hostname = otherHostname, Port = otherPort };
else
incomingNodeConnections[otherGuid] = new NetworkNode { Hostname = otherHostname, Port = otherPort };
}
private static Task SendLeaderElectionResponse(LeaderElectionState electionState, NetworkNode nodeTuple, bool responseState, bool uniqueState, bool uselessState)
{
var uriBuilder = new UriBuilder(Uri.UriSchemeHttp, nodeTuple.Hostname, nodeTuple.Port, "/secondYo/Response");
var reqDataString = string.Join(Environment.NewLine,
electionState.Guid, electionState.CreationTime.ToString("o"), nodeGuid, responseState, uniqueState, uselessState);
var reqDataBytes = Encoding.ASCII.GetBytes(reqDataString);
return SendNotificationPostRequestToNode(uriBuilder.Uri, reqDataBytes);
}
private static Task SendLeaderElectionAdvertisement(LeaderElectionState electionState, NetworkNode nodeTuple, Guid advertGuid)
{
var uriBuilder = new UriBuilder(Uri.UriSchemeHttp, nodeTuple.Hostname, nodeTuple.Port, "/firstYo/Advertise");
var reqDataString = string.Join(Environment.NewLine, electionState.Guid, electionState.CreationTime.ToString("o"), nodeGuid, advertGuid);
var reqDataBytes = Encoding.ASCII.GetBytes(reqDataString);
return SendNotificationPostRequestToNode(uriBuilder.Uri, reqDataBytes);
}
private static async Task SendSecondYoFlipNode(NetworkNode nodeTuple)
{
var uriBuilder = new UriBuilder(Uri.UriSchemeHttp, nodeTuple.Hostname, nodeTuple.Port, "/secondYo/Flip");
var req = WebRequest.Create(uriBuilder.Uri) as HttpWebRequest;
req.Method = WebRequestMethods.Http.Post;
req.ContentType = new ContentType(MediaTypeNames.Text.Plain) { CharSet = Encoding.ASCII.WebName }.ToString();
var reqDataString = nodeGuid.ToString() + Environment.NewLine;
var reqDataBytes = Encoding.ASCII.GetBytes(reqDataString);
req.ContentLength = reqDataBytes.LongLength;
try
{
using (var reqStream = await req.GetRequestStreamAsync())
{
await reqStream.WriteAsync(reqDataBytes, 0, reqDataBytes.Length);
await reqStream.FlushAsync();
}
using (var resp = await req.GetResponseAsync()) { }
}
catch (WebException) { }
}
private static async void HandleHttpContext(HttpListener http_listener)
{
HttpListenerContext http_ctx;
try { http_ctx = await http_listener.GetContextAsync(); }
catch (Exception) { return; }
//nodeStateLock.EnterReadLock();
try
{
HandleHttpContext(http_listener);
var path = http_ctx.Request.Url.AbsolutePath;
if (string.Equals("/getCurrentLeader", path, StringComparison.OrdinalIgnoreCase))
{
var inNodeKvps = incomingNodeConnections.ToArray();
var outNodeKvps = outgoingNodeConnections.ToArray();
var newElectionState = new LeaderElectionState(inNodeKvps.Where(kvp => !kvp.Value.IsUselessConnection).Select(kvp => kvp.Key),
outNodeKvps.Where(kvp => !kvp.Value.IsUselessConnection).Select(kvp => kvp.Key))
{ Guid = Guid.NewGuid(), CreationTime = DateTime.Now, FirstYoMinimum = nodeGuid };
leaderElections[newElectionState.Guid] = newElectionState;
SendLeaderElectionAdvertisementRequest(newElectionState, new NetworkNode { Hostname = "localhost", Port = portNumber }).Wait();
Guid? currentLeader;
do
{
Task.Delay(42).Wait();
currentLeader = leaderGuid;
} while (currentLeader == null);
NetworkNode leaderNode;
if (currentLeader == nodeGuid)
leaderNode = new NetworkNode { Hostname = http_ctx.Request.LocalEndPoint.Address.ToString(), Port = portNumber };
else if (!incomingNodeConnections.TryGetValue(currentLeader.GetValueOrDefault(), out leaderNode))
{
http_ctx.Response.StatusCode = (int)HttpStatusCode.NotFound;
http_ctx.Response.Close();
}
http_ctx.Response.ContentType = MediaTypeNames.Text.Plain;
http_ctx.Response.ContentEncoding = Encoding.ASCII;
http_ctx.Response.StatusCode = (int)HttpStatusCode.OK;
http_ctx.Response.Close(Encoding.ASCII.GetBytes(string.Format("{0}:{1}", leaderNode.Hostname, leaderNode.Port)), willBlock: false);
}
else if (string.Equals("/getNodes", path, StringComparison.OrdinalIgnoreCase))
{
GetNodesContext(http_ctx);
}
else if (string.Equals("/getNodesWithGuids", path, StringComparison.OrdinalIgnoreCase))
{
GetNodesContext(http_ctx, withGuids: true);
}
else if (string.Equals("/getGuid", path, StringComparison.OrdinalIgnoreCase))
{
GetGuidContext(http_ctx);
}
else if (string.Equals("/connectToNodes", path, StringComparison.OrdinalIgnoreCase))
{
await ConnectToNodesContext(http_ctx);
}
else if (string.Equals("/registerNeighbour", path, StringComparison.OrdinalIgnoreCase))
{
RegisterNeighbourContext(http_ctx);
}
else if (string.Equals("/clearConnections", path, StringComparison.OrdinalIgnoreCase))
{
ClearConnectionsContext(http_ctx);
}
else if (string.Equals("/deregisterNode", path, StringComparison.OrdinalIgnoreCase))
{
await DeregisterNodeContext(http_ctx);
}
else if (string.Equals("/firstYo/Advertise", path, StringComparison.OrdinalIgnoreCase))
{
FirstYoAdvertisementContext(http_ctx);
}
else if (string.Equals("/firstYo/RequestAdvertisement", path, StringComparison.OrdinalIgnoreCase))
{
FirstYoRequestAdvertisementContext(http_ctx);
}
else if (string.Equals("/secondYo/Response", path, StringComparison.OrdinalIgnoreCase))
{
SecondYoResponseContext(http_ctx);
}
else if (string.Equals("/secondYo/Flip", path, StringComparison.OrdinalIgnoreCase))
{
SecondYoFlipContext(http_ctx);
}
else
{
http_ctx.Response.ContentType = MediaTypeNames.Text.Plain;
http_ctx.Response.ContentEncoding = Encoding.ASCII;
http_ctx.Response.StatusCode = (int)HttpStatusCode.NotFound;
http_ctx.Response.Close(Encoding.ASCII.GetBytes("The requested resource could not be found."), willBlock: false);
}
}
finally
{
//nodeStateLock.ExitReadLock();
}
}
