Move congestion control to its own class
It's a general function and it's better to have that particular
complexity in its own place.
diff --git a/common/rfb/Congestion.h b/common/rfb/Congestion.h
new file mode 100644
index 0000000..e8548f9
--- /dev/null
+++ b/common/rfb/Congestion.h
@@ -0,0 +1,62 @@
+/* Copyright 2009-2015 Pierre Ossman for Cendio AB
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#ifndef __RFB_CONGESTION_H__
+#define __RFB_CONGESTION_H__
+
+#include <list>
+
+#include <rfb/Timer.h>
+
+namespace rfb {
+ class Congestion : public Timer::Callback {
+ public:
+ Congestion();
+ ~Congestion();
+
+ // sentPing() must be called when a marker is placed on the
+ // outgoing stream, along with the current stream position.
+ // gotPong() must be called when the response for such a marker
+ // is received.
+ void sentPing(int offset);
+ void gotPong();
+
+ // isCongested() determines if the transport is currently congested
+ // or if more data can be sent. The curren stream position and how
+ // long the transport has been idle must be specified.
+ bool isCongested(int offset, unsigned idleTime);
+
+ private:
+ // Timer callbacks
+ virtual bool handleTimeout(Timer* t);
+
+ private:
+ unsigned baseRTT;
+ unsigned congWindow;
+ unsigned ackedOffset, sentOffset;
+
+ unsigned minRTT;
+ bool seenCongestion;
+ Timer congestionTimer;
+
+ struct RTTInfo;
+ std::list<struct RTTInfo> pings;
+ };
+}
+
+#endif