93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
/*
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* Smoother.h
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*
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* This source file is part of the FoundationDB open source project
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*
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* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef FLOW_SMOOTHER_H
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#define FLOW_SMOOTHER_H
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#pragma once
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#include "flow/flow.h"
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struct Smoother {
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// Times (t) are expected to be nondecreasing
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explicit Smoother( double eFoldingTime ) : eFoldingTime(eFoldingTime) { reset(0); }
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void reset(double value) { time = 0; total = value; estimate = value; }
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void setTotal( double total, double t = now() ) { addDelta( total - this->total, t); }
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void addDelta( double delta, double t = now() ) {
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update(t);
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total += delta;
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}
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// smoothTotal() is a continuous (under)estimate of the sum of all addDeltas()
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double smoothTotal( double t = now() ) {
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update(t);
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return estimate;
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}
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// smoothRate() is d/dt[smoothTotal], and is NOT continuous
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double smoothRate( double t = now() ) {
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update(t);
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return (total-estimate) / eFoldingTime;
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}
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void update(double t) {
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double elapsed = t - time;
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if(elapsed) {
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time = t;
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estimate += (total-estimate) * (1-exp( -elapsed/eFoldingTime ));
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}
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}
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double eFoldingTime;
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double time, total, estimate;
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};
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struct TimerSmoother {
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// Times (t) are expected to be nondecreasing
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explicit TimerSmoother( double eFoldingTime ) : eFoldingTime(eFoldingTime) { reset(0); }
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void reset(double value) { time = 0; total = value; estimate = value; }
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void setTotal( double total, double t = timer() ) { addDelta( total - this->total, t); }
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void addDelta( double delta, double t = timer() ) {
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update(t);
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total += delta;
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}
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// smoothTotal() is a continuous (under)estimate of the sum of all addDeltas()
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double smoothTotal( double t = timer() ) {
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update(t);
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return estimate;
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}
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// smoothRate() is d/dt[smoothTotal], and is NOT continuous
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double smoothRate( double t = timer() ) {
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update(t);
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return (total-estimate) / eFoldingTime;
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}
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void update(double t) {
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double elapsed = t - time;
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time = t;
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estimate += (total-estimate) * (1-exp( -elapsed/eFoldingTime ));
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}
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double eFoldingTime;
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double time, total, estimate;
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};
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#endif |