Initial commit

2020-09-20 12:16:44 +00:00
parent 09a4460ddb
commit 408c005d3e
839 changed files with 190481 additions and 0 deletions
--- a/common/rfb/Congestion.h
+++ b/common/rfb/Congestion.h
@@ -0,0 +1,95 @@
+/* Copyright 2009-2018 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>
+
+namespace rfb {
+  class Congestion {
+  public:
+    Congestion();
+    ~Congestion();
+
+    // updatePosition() registers the current stream position and can
+    // and should be called often.
+    void updatePosition(unsigned pos);
+
+    // sentPing() must be called when a marker is placed on the
+    // outgoing stream. gotPong() must be called when the response for
+    // such a marker is received.
+    void sentPing();
+    void gotPong();
+
+    // isCongested() determines if the transport is currently congested
+    // or if more data can be sent.
+    bool isCongested();
+
+    // getUncongestedETA() returns the number of milliseconds until the
+    // transport is no longer congested. Returns 0 if there is no
+    // congestion, and -1 if it is unknown when the transport will no
+    // longer be congested.
+    int getUncongestedETA();
+
+    // getBandwidth() returns the current bandwidth estimation in bytes
+    // per second.
+    size_t getBandwidth();
+
+    // debugTrace() writes the current congestion window, as well as the
+    // congestion window of the underlying TCP layer, to the specified
+    // file
+    void debugTrace(const char* filename, int fd);
+
+  protected:
+    unsigned getExtraBuffer();
+    unsigned getInFlight();
+
+    void updateCongestion();
+
+  private:
+    unsigned lastPosition;
+    unsigned extraBuffer;
+    struct timeval lastUpdate;
+    struct timeval lastSent;
+
+    unsigned baseRTT;
+    unsigned congWindow;
+    bool inSlowStart;
+
+    unsigned safeBaseRTT;
+
+    struct RTTInfo {
+      struct timeval tv;
+      unsigned pos;
+      unsigned extra;
+      bool congested;
+    };
+
+    std::list<struct RTTInfo> pings;
+
+    struct RTTInfo lastPong;
+    struct timeval lastPongArrival;
+
+    int measurements;
+    struct timeval lastAdjustment;
+    unsigned minRTT, minCongestedRTT;
+  };
+}
+
+#endif