internal async Task <NotHttpConnection> GetRequestConnection(NHClientRequest caller)
{
NHClientEndpoint endpoint;
Task <NotHttpConnection> blockTask;
lock (this)
{
Uri url = caller.Url;
Dictionary <int, NHClientEndpoint> hostPorts;
if (!connections.TryGetValue(url.Host, out hostPorts))
{
hostPorts = new Dictionary <int, NHClientEndpoint>();
connections.Add(url.Host, hostPorts);
}
if (!hostPorts.TryGetValue(url.Port, out endpoint))
{
endpoint = new NHClientEndpoint(url.Host, url.Port, isOverlapped, maxConnections, idleTimeout, logger);
hostPorts.Add(url.Port, endpoint);
}
blockTask = endpoint.WaitForRequestSlot(caller);
}
return(await blockTask);
}
public Exception AssignRequest(NHClientRequest request)
{
lock (this)
{
if (currentRequest != null)
{
endpoint.Logger.Log("Error: callers out of sync");
throw new ApplicationException("Callers out of sync");
}
// if exception is non-null the connection is faulted, and
// will be discarded by the caller when this method returns
if (exception == null)
{
currentRequest = request;
if (outstandingRequests == 0)
{
idleTask.SetResult(false);
}
++outstandingRequests;
}
return(exception);
}
}
public void StreamFaulted(Exception e)
{
lock (this)
{
if (stream == null)
{
// already faulted
return;
}
StreamFaultedInternal(e);
if (!endpoint.IsOverlapped)
{
currentRequest = null;
}
}
if (!endpoint.IsOverlapped)
{
// take ourselves out of the endpoint's list of available connections; ReportConnectionReady
// checks to see if we are faulted. For an overlapped connection this will have happened in
// ReportRequestCompleted already
endpoint.ReportConnectionReady(this);
}
}
public int NextSequenceNumber(NHClientRequest caller)
{
lock (this)
{
if (caller != currentRequest)
{
endpoint.Logger.Log("Error: callers out of sync");
throw new ApplicationException("Callers out of sync");
}
// I don't believe in foo++ syntax obfuscation :)
int sn = sequenceNumber;
++sequenceNumber;
return(sn);
}
}
public void ReportRequestCompleted(NHClientRequest caller)
{
lock (this)
{
if (caller != currentRequest)
{
endpoint.Logger.Log("Error: callers out of sync");
throw new ApplicationException("Callers out of sync");
}
if (endpoint.IsOverlapped)
{
currentRequest = null;
}
}
if (endpoint.IsOverlapped)
{
endpoint.ReportConnectionReady(this);
}
}
public async Task <NotHttpConnection> WaitForRequestSlot(NHClientRequest caller)
{
Task <NotHttpConnection> blockTask = null;
lock (this)
{
// this is where we garbage collection connections that are faulted, so
// go through the idle connections throwing them away if they
// aren't good until we match one
while (blockTask == null && idleConnections.Count > 0)
{
NotHttpConnection connection = idleConnections.Pop();
Exception exception = connection.AssignRequest(caller);
if (exception == null)
{
blockTask = Task.FromResult(connection);
}
else
{
--openedConnections;
logger.Log("Removing faulted connection, " + openedConnections + " remaining: " + exception.Message);
}
}
if (blockTask == null)
{
RequestWaiter waiter = new RequestWaiter(caller);
requestWaiters.AddLast(waiter);
blockTask = waiter.task.Task;
}
ReOpenConnections();
}
return(await blockTask);
}
public RequestWaiter(NHClientRequest caller)
{
request = caller;
task = new TaskCompletionSource <NotHttpConnection>();
}
private async Task ReadStream()
{
int responseSequenceNumber = -1;
while (true)
{
Task <bool> idleBlocker = null;
lock (this)
{
if (outstandingRequests == 0)
{
// add ContinueWith so the continuation is asynchronous, since await generates
// a synchronous continuation
idleBlocker = idleTask.Task.ContinueWith((t) => t.Result);
}
}
if (idleBlocker != null)
{
bool mustExit = await idleBlocker;
if (mustExit)
{
endpoint.Logger.Log("Reader exiting due to idle connection");
return;
}
}
if (!endpoint.IsOverlapped)
{
// sequence number is 0 for the first response
++responseSequenceNumber;
}
// for an overlapped connection we pass in responseSequenceNumber=-1 and the actual sequence
// number is read from the protocol. For a sequential connection we pass in the actual sequence
// number
NHClientResponse response = new NHClientResponse(this, responseSequenceNumber, endpoint.Logger);
try
{
NotHttp.NHError error = new NotHttp.NHError();
bool gotRequest = await response.Parse(null, stream, error);
if (!gotRequest)
{
throw new ApplicationException("Server closed connection");
}
if (response.StatusCode != HttpStatusCode.OK || endpoint.IsOverlapped)
{
// fetch the whole response now, so we're ready to wait for the next message even if
// the caller isn't ready to read this one
await response.BufferInput();
}
lock (this)
{
TaskCompletionSource <IHttpResponse> tcs;
if (pendingClients.TryGetValue(response.SequenceNumber, out tcs))
{
// run this asynchronously outside the lock
Task abandon = Task.Run(() => ReturnResult(tcs, response));
pendingClients.Remove(response.SequenceNumber);
}
else
{
if (receivedResponses.ContainsKey(response.SequenceNumber))
{
StreamFaulted(new ApplicationException("Received duplicate sequence numbers " + response.SequenceNumber));
return;
}
receivedResponses.Add(response.SequenceNumber, response);
}
}
// wait until the caller has consumed all the payload data (if we buffered it above this
// falls through immediately)
await response.Completed;
string closeHeader = response.HeadersInternal[HttpRequestHeader.Connection];
if (closeHeader != null && closeHeader.ToLower() == "close")
{
endpoint.Logger.Log("Passing stream connection closed header");
StreamFaulted(new ApplicationException("Connection closed by server request"));
return;
}
lock (this)
{
if (!endpoint.IsOverlapped)
{
currentRequest = null;
}
--outstandingRequests;
if (outstandingRequests == 0)
{
idleTask = new TaskCompletionSource <bool>();
// capture member variable in local scope to give to closure
TaskCompletionSource <bool> currentIdleTask = idleTask;
Task abandon = Task.Delay(endpoint.IdleTimeout).ContinueWith((t) => ExitOnIdle(currentIdleTask));
}
}
if (!endpoint.IsOverlapped)
{
endpoint.ReportConnectionReady(this);
}
}
catch (Exception e)
{
endpoint.Logger.Log("Passing exception status " + response.StatusCode);
StreamFaulted(e);
return;
}
}
}