Add files for swift over UDP.

[swifty.git] / src / libswift_udp / avgspeed.cpp

diff --git a/src/libswift_udp/avgspeed.cpp b/src/libswift_udp/avgspeed.cpp
new file mode 100644 (file)
index 0000000..2bc8607
--- /dev/null
+++ b/src/libswift_udp/avgspeed.cpp
@@ -0,0 +1,64 @@
+/*
+ *  avgspeed.cpp
+ *  Class to compute moving average speed
+ *
+ *  Created by Arno Bakker
+ *  Copyright 2009 Delft University of Technology. All rights reserved.
+ *
+ */
+#include "avgspeed.h"
+
+using namespace swift;
+
+MovingAverageSpeed::MovingAverageSpeed(tint speed_interval, tint fudge)
+{
+    speed_interval_ = speed_interval;
+    fudge_ = fudge;
+       t_start_ = usec_time() - fudge_;
+       t_end_ = t_start_;
+       speed_ = 0.0;
+       resetstate_ = false;
+}
+
+
+void MovingAverageSpeed::AddPoint(uint64_t amount)
+{
+       // Arno, 2012-01-04: Resetting this measurement includes not adding
+       // points for a few seconds after the reset, to accomodate the case
+       // of going from high speed to low speed and content still coming in.
+       //
+       if (resetstate_) {
+               if ((t_start_ + speed_interval_/2) > usec_time()) {
+                       return;
+               }
+               resetstate_ = false;
+       }
+
+    tint t = usec_time();
+    speed_ = (speed_ * ((double)(t_end_ - t_start_)/((double)TINT_SEC)) + (double)amount) / ((t - t_start_)/((double)TINT_SEC) + 0.0001);
+    t_end_ = t;
+    if (t_start_ < t - speed_interval_)
+        t_start_ = t - speed_interval_;
+}
+
+
+double MovingAverageSpeed::GetSpeed()
+{
+    AddPoint(0);
+    return speed_;
+}
+
+
+double MovingAverageSpeed::GetSpeedNeutral()
+{
+    return speed_;
+}
+
+
+void MovingAverageSpeed::Reset()
+{
+       resetstate_ = true;
+       t_start_ = usec_time() - fudge_;
+       t_end_ = t_start_;
+       speed_ = 0.0;
+}