RateEstimator.cc

Go to the documentation of this file.
00001 /*
00002  *    Copyright 2004-2006 Intel Corporation
00003  * 
00004  *    Licensed under the Apache License, Version 2.0 (the "License");
00005  *    you may not use this file except in compliance with the License.
00006  *    You may obtain a copy of the License at
00007  * 
00008  *        http://www.apache.org/licenses/LICENSE-2.0
00009  * 
00010  *    Unless required by applicable law or agreed to in writing, software
00011  *    distributed under the License is distributed on an "AS IS" BASIS,
00012  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  *    See the License for the specific language governing permissions and
00014  *    limitations under the License.
00015  */
00016 
00017 
00018 #include "RateEstimator.h"
00019 
00020 namespace oasys {
00021 
00022 RateEstimator::RateEstimator(int *var, int interval, double weight)
00023 {
00024     var_ = var;
00025     weight_ = weight;
00026     lastval_ = 0;
00027     rate_ = 0.0;
00028     lastts_.tv_sec = 0;
00029     lastts_.tv_usec = 0;
00030 
00031     schedule_in(interval);
00032 }
00033 
00034 void
00035 RateEstimator::timeout(struct timeval* now)
00036 {
00037     if (lastts_.tv_sec == 0 && lastts_.tv_usec == 0) {
00038         // first time through
00039         rate_    = 0.0;
00040  done:
00041         lastval_ = *var_;
00042         lastts_  = *now;
00043         schedule_in(interval_);
00044         return;
00045     }
00046     
00047     double dv = (double)(*var_ - lastval_);
00048     double dt = TIMEVAL_DIFF_DOUBLE(*now, lastts_);
00049     
00050     double newrate = dv/dt;
00051     double oldrate = rate_;
00052     double delta   = newrate - oldrate;
00053 
00054     rate_ += delta * weight_;
00055 
00056     goto done;
00057 }
00058 
00059 } // namespace oasys

Generated on Thu Jun 7 16:56:51 2007 for DTN Reference Implementation by  doxygen 1.5.1