RateEstimator.cc

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00001 /*
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00007  * Intel Open Source License 
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00038 
00039 #include "RateEstimator.h"
00040 
00041 namespace oasys {
00042 
00043 RateEstimator::RateEstimator(int *var, int interval, double weight)
00044 {
00045     var_ = var;
00046     weight_ = weight;
00047     lastval_ = 0;
00048     rate_ = 0.0;
00049     lastts_.tv_sec = 0;
00050     lastts_.tv_usec = 0;
00051 
00052     schedule_in(interval);
00053 }
00054 
00055 void
00056 RateEstimator::timeout(struct timeval* now)
00057 {
00058     if (lastts_.tv_sec == 0 && lastts_.tv_usec == 0) {
00059         // first time through
00060         rate_    = 0.0;
00061  done:
00062         lastval_ = *var_;
00063         lastts_  = *now;
00064         schedule_in(interval_);
00065         return;
00066     }
00067     
00068     double dv = (double)(*var_ - lastval_);
00069     double dt = TIMEVAL_DIFF_DOUBLE(*now, lastts_);
00070     
00071     double newrate = dv/dt;
00072     double oldrate = rate_;
00073     double delta   = newrate - oldrate;
00074 
00075     rate_ += delta * weight_;
00076 
00077     goto done;
00078 }
00079 
00080 } // namespace oasys

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