public HTTP2Stream(HTTP2SettingsManager registry, HPACKEncoder hpackEncoder, UInt32 id)
{
this.settings = registry;
this.encoder = hpackEncoder;
this.Id = id;
this.remoteWindow = this.settings.RemoteSettings[HTTP2Settings.INITIAL_WINDOW_SIZE];
this.settings.RemoteSettings.OnSettingChangedEvent += OnRemoteSettingChanged;
// Room for improvement: If INITIAL_WINDOW_SIZE is small (what we can consider a 'small' value?), threshold must be higher
this.windowUpdateThreshold = (uint)(this.remoteWindow / 2);
}
/// <summary>
/// Constructor to create a client stream.
/// </summary>
public HTTP2Stream(HTTP2SettingsManager registry, HPACKEncoder hpackEncoder)
: this(registry, hpackEncoder, (UInt32)Interlocked.Add(ref LastStreamId, 2))
{
}
public void RunHandler()
{
HTTPManager.Logger.Information("HTTP2Handler", "Processing thread up and running!");
Thread.CurrentThread.Name = "HTTP2 Process";
PlatformSupport.Threading.ThreadedRunner.RunLongLiving(ReadThread);
try
{
bool atLeastOneStreamHasAFrameToSend = true;
this.HPACKEncoder = new HPACKEncoder(this.settings);
// https://httpwg.org/specs/rfc7540.html#InitialWindowSize
// The connection flow-control window is also 65,535 octets.
this.remoteWindow = this.settings.RemoteSettings[HTTP2Settings.INITIAL_WINDOW_SIZE];
// we want to pack as many data as we can in one tcp segment, but setting the buffer's size too high
// we might keep data too long and send them in bursts instead of in a steady stream.
// Keeping it too low might result in a full tcp segment and one with very low payload
// Is it possible that one full tcp segment sized buffer would be the best, or multiple of it.
// It would keep the network busy without any fragments. The ethernet layer has a maximum of 1500 bytes,
// but there's two layers of 20 byte headers each, so as a theoretical maximum it's 1500-20-20 bytes.
// On the other hand, if the buffer is small (1-2), that means that for larger data, we have to do a lot
// of system calls, in that case a larger buffer might be better. Still, if we are not cpu bound,
// a well saturated network might serve us better.
using (WriteOnlyBufferedStream bufferedStream = new WriteOnlyBufferedStream(this.conn.connector.Stream, 1024 * 1024 /*1500 - 20 - 20*/))
{
// The client connection preface starts with a sequence of 24 octets
bufferedStream.Write(MAGIC, 0, MAGIC.Length);
// This sequence MUST be followed by a SETTINGS frame (Section 6.5), which MAY be empty.
// The client sends the client connection preface immediately upon receipt of a
// 101 (Switching Protocols) response (indicating a successful upgrade)
// or as the first application data octets of a TLS connection
// Set streams' initial window size to its maximum.
this.settings.InitiatedMySettings[HTTP2Settings.INITIAL_WINDOW_SIZE] = HTTPManager.HTTP2Settings.InitialStreamWindowSize;
this.settings.InitiatedMySettings[HTTP2Settings.MAX_CONCURRENT_STREAMS] = HTTPManager.HTTP2Settings.MaxConcurrentStreams;
this.settings.SendChanges(this.outgoingFrames);
// The default window size for the whole connection is 65535 bytes,
// but we want to set it to the maximum possible value.
Int64 diff = HTTPManager.HTTP2Settings.InitialConnectionWindowSize - 65535;
if (diff > 0)
{
this.outgoingFrames.Add(HTTP2FrameHelper.CreateWindowUpdateFrame(0, (UInt32)diff));
}
this.pingFrequency = HTTPManager.HTTP2Settings.PingFrequency;
while (this.isRunning)
{
if (!atLeastOneStreamHasAFrameToSend)
{
// buffered stream will call flush automatically if its internal buffer is full.
// But we have to make it sure that we flush remaining data before we go to sleep.
bufferedStream.Flush();
// Wait until we have to send the next ping, OR a new frame is received on the read thread.
// Sent Now Sent+frequency
//-----|--------|----|------------
int wait = (int)((this.lastPingSent + this.pingFrequency) - DateTime.UtcNow).TotalMilliseconds;
wait = (int)Math.Min(wait, this.MaxGoAwayWaitTime.TotalMilliseconds);
if (wait >= 1)
{
if (HTTPManager.Logger.Level <= Logger.Loglevels.All)
{
HTTPManager.Logger.Information("HTTP2Handler", string.Format("Sleeping for {0:N0}ms", wait));
}
this.newFrameSignal.WaitOne(wait);
}
}
DateTime now = DateTime.UtcNow;
if (now - this.lastPingSent >= this.pingFrequency)
{
this.lastPingSent = now;
var frame = HTTP2FrameHelper.CreatePingFrame(HTTP2PingFlags.None);
BufferHelper.SetLong(frame.Payload, 0, now.Ticks);
this.outgoingFrames.Add(frame);
}
// Process received frames
HTTP2FrameHeaderAndPayload header;
while (this.newFrames.TryDequeue(out header))
{
if (header.StreamId > 0)
{
HTTP2Stream http2Stream = FindStreamById(header.StreamId);
// Add frame to the stream, so it can process it when its Process function is called
if (http2Stream != null)
{
http2Stream.AddFrame(header, this.outgoingFrames);
}
else
{
// Error? It's possible that we closed and removed the stream while the server was in the middle of sending frames
//HTTPManager.Logger.Warning("HTTP2Handler", string.Format("No stream found for id: {0}! Can't deliver frame: {1}", header.StreamId, header));
}
}
else
{
switch (header.Type)
{
case HTTP2FrameTypes.SETTINGS:
this.settings.Process(header, this.outgoingFrames);
break;
case HTTP2FrameTypes.PING:
var pingFrame = HTTP2FrameHelper.ReadPingFrame(header);
// if it wasn't an ack for our ping, we have to send one
if ((pingFrame.Flags & HTTP2PingFlags.ACK) == 0)
{
var frame = HTTP2FrameHelper.CreatePingFrame(HTTP2PingFlags.ACK);
Array.Copy(pingFrame.OpaqueData, 0, frame.Payload, 0, pingFrame.OpaqueDataLength);
this.outgoingFrames.Add(frame);
}
break;
case HTTP2FrameTypes.WINDOW_UPDATE:
var windowUpdateFrame = HTTP2FrameHelper.ReadWindowUpdateFrame(header);
this.remoteWindow += windowUpdateFrame.WindowSizeIncrement;
break;
case HTTP2FrameTypes.GOAWAY:
// parse the frame, so we can print out detailed information
HTTP2GoAwayFrame goAwayFrame = HTTP2FrameHelper.ReadGoAwayFrame(header);
HTTPManager.Logger.Information("HTTP2Handler", "Received GOAWAY frame: " + goAwayFrame.ToString());
string msg = string.Format("Server closing the connection! Error code: {0} ({1})", goAwayFrame.Error, goAwayFrame.ErrorCode);
for (int i = 0; i < this.clientInitiatedStreams.Count; ++i)
{
this.clientInitiatedStreams[i].Abort(msg);
}
// set the running flag to false, so the thread can exit
this.isRunning = false;
this.conn.State = HTTPConnectionStates.Closed;
break;
case HTTP2FrameTypes.ALT_SVC:
//HTTP2AltSVCFrame altSvcFrame = HTTP2FrameHelper.ReadAltSvcFrame(header);
// Implement
//HTTPManager.EnqueuePluginEvent(new PluginEventInfo(PluginEvents.AltSvcHeader, new AltSvcEventInfo(altSvcFrame.Origin, ))
break;
}
}
}
UInt32 maxConcurrentStreams = Math.Min(HTTPManager.HTTP2Settings.MaxConcurrentStreams, this.settings.RemoteSettings[HTTP2Settings.MAX_CONCURRENT_STREAMS]);
// pre-test stream count to lock only when truly needed.
if (this.clientInitiatedStreams.Count < maxConcurrentStreams && this.isRunning)
{
// grab requests from queue
HTTPRequest request;
while (this.clientInitiatedStreams.Count < maxConcurrentStreams && this.requestQueue.TryDequeue(out request))
{
// create a new stream
var newStream = new HTTP2Stream((UInt32)Interlocked.Add(ref LastStreamId, 2), this.settings, this.HPACKEncoder);
// process the request
newStream.Assign(request);
this.clientInitiatedStreams.Add(newStream);
}
}
// send any settings changes
this.settings.SendChanges(this.outgoingFrames);
atLeastOneStreamHasAFrameToSend = false;
// process other streams
// Room for improvement Streams should be processed by their priority!
for (int i = 0; i < this.clientInitiatedStreams.Count; ++i)
{
var stream = this.clientInitiatedStreams[i];
stream.Process(this.outgoingFrames);
// remove closed, empty streams (not enough to check the closed flag, a closed stream still can contain frames to send)
if (stream.State == HTTP2StreamStates.Closed && !stream.HasFrameToSend)
{
this.clientInitiatedStreams.RemoveAt(i--);
stream.Removed();
}
atLeastOneStreamHasAFrameToSend |= stream.HasFrameToSend;
this.lastInteraction = DateTime.UtcNow;
}
// If we encounter a data frame that too large for the current remote window, we have to stop
// sending all data frames as we could send smaller data frames before the large ones.
// Room for improvement: An improvement would be here to stop data frame sending per-stream.
bool haltDataSending = false;
if (this.ShutdownType == ShutdownTypes.Running && now - this.lastInteraction >= HTTPManager.HTTP2Settings.MaxIdleTime)
{
this.lastInteraction = DateTime.UtcNow;
HTTPManager.Logger.Information("HTTP2Handler", "Reached idle time, sending GoAway frame!");
this.outgoingFrames.Add(HTTP2FrameHelper.CreateGoAwayFrame(0, HTTP2ErrorCodes.NO_ERROR));
this.goAwaySentAt = DateTime.UtcNow;
}
// https://httpwg.org/specs/rfc7540.html#GOAWAY
// Endpoints SHOULD always send a GOAWAY frame before closing a connection so that the remote peer can know whether a stream has been partially processed or not.
if (this.ShutdownType == ShutdownTypes.Gentle)
{
HTTPManager.Logger.Information("HTTP2Handler", "Connection abort requested, sending GoAway frame!");
this.outgoingFrames.Clear();
this.outgoingFrames.Add(HTTP2FrameHelper.CreateGoAwayFrame(0, HTTP2ErrorCodes.NO_ERROR));
this.goAwaySentAt = DateTime.UtcNow;
}
if (this.isRunning && now - goAwaySentAt >= this.MaxGoAwayWaitTime)
{
HTTPManager.Logger.Information("HTTP2Handler", "No GoAway frame received back. Really quitting now!");
this.isRunning = false;
conn.State = HTTPConnectionStates.Closed;
}
uint streamWindowUpdates = 0;
// Go through all the collected frames and send them.
for (int i = 0; i < this.outgoingFrames.Count; ++i)
{
var frame = this.outgoingFrames[i];
if (HTTPManager.Logger.Level <= Logger.Loglevels.All && frame.Type != HTTP2FrameTypes.DATA /*&& frame.Type != HTTP2FrameTypes.PING*/)
{
HTTPManager.Logger.Information("HTTP2Handler", "Sending frame: " + frame.ToString());
}
// post process frames
switch (frame.Type)
{
case HTTP2FrameTypes.DATA:
if (haltDataSending)
{
continue;
}
// if the tracked remoteWindow is smaller than the frame's payload, we stop sending
// data frames until we receive window-update frames
if (frame.PayloadLength > this.remoteWindow)
{
haltDataSending = true;
HTTPManager.Logger.Warning("HTTP2Handler", string.Format("Data sending halted for this round. Remote Window: {0:N0}, frame: {1}", this.remoteWindow, frame.ToString()));
continue;
}
break;
case HTTP2FrameTypes.WINDOW_UPDATE:
if (frame.StreamId > 0)
{
streamWindowUpdates += BufferHelper.ReadUInt31(frame.Payload, 0);
}
break;
}
this.outgoingFrames.RemoveAt(i--);
using (var buffer = HTTP2FrameHelper.HeaderAsBinary(frame))
bufferedStream.Write(buffer.Data, 0, buffer.Length);
if (frame.PayloadLength > 0)
{
bufferedStream.Write(frame.Payload, (int)frame.PayloadOffset, (int)frame.PayloadLength);
if (!frame.DontUseMemPool)
{
BufferPool.Release(frame.Payload);
}
}
if (frame.Type == HTTP2FrameTypes.DATA)
{
this.remoteWindow -= frame.PayloadLength;
}
}
if (streamWindowUpdates > 0)
{
var frame = HTTP2FrameHelper.CreateWindowUpdateFrame(0, streamWindowUpdates);
if (HTTPManager.Logger.Level <= Logger.Loglevels.All)
{
HTTPManager.Logger.Information("HTTP2Handler", "Sending frame: " + frame.ToString());
}
using (var buffer = HTTP2FrameHelper.HeaderAsBinary(frame))
bufferedStream.Write(buffer.Data, 0, buffer.Length);
bufferedStream.Write(frame.Payload, (int)frame.PayloadOffset, (int)frame.PayloadLength);
}
} // while (this.isRunning)
bufferedStream.Flush();
}
}
catch (Exception ex)
{
// Log out the exception if it's a non-expected one.
if (this.ShutdownType == ShutdownTypes.Running && this.goAwaySentAt == DateTime.MaxValue)
{
HTTPManager.Logger.Exception("HTTP2Handler", "Sender thread", ex);
}
}
finally
{
// First thread closing notifies the ConnectionEventHelper
if (Interlocked.Increment(ref this.threadExitCount) == 1)
{
ConnectionEventHelper.EnqueueConnectionEvent(new ConnectionEventInfo(this.conn, HTTPConnectionStates.Closed));
}
HTTPManager.Logger.Information("HTTP2Handler", "Sender thread closing - cleaning up remaining request...");
for (int i = 0; i < this.clientInitiatedStreams.Count; ++i)
{
this.clientInitiatedStreams[i].Abort("Connection closed unexpectedly");
}
this.clientInitiatedStreams.Clear();
HTTPRequest request = null;
while (this.requestQueue.TryDequeue(out request))
{
HTTPManager.Logger.Information("HTTP2Handler", string.Format("Request '{0}' IsCancellationRequested: {1}", request.CurrentUri.ToString(), request.IsCancellationRequested.ToString()));
if (request.IsCancellationRequested)
{
request.Response = null;
request.State = HTTPRequestStates.Aborted;
}
else
{
RequestEventHelper.EnqueueRequestEvent(new RequestEventInfo(request, RequestEvents.Resend));
}
}
HTTPManager.Logger.Information("HTTP2Handler", "Sender thread closing");
}
try
{
// Works in the new runtime
if (this.conn.connector.TopmostStream != null)
{
using (this.conn.connector.TopmostStream) { }
}
// Works in the old runtime
if (this.conn.connector.Stream != null)
{
using (this.conn.connector.Stream) { }
}
}
catch
{ }
}
