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