Junxiao Shi | 02e3224 | 2014-05-17 20:51:11 -0700 | [diff] [blame] | 1 | /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */ |
| 2 | /** |
| 3 | * Copyright (c) 2014 Regents of the University of California, |
| 4 | * Arizona Board of Regents, |
| 5 | * Colorado State University, |
| 6 | * University Pierre & Marie Curie, Sorbonne University, |
| 7 | * Washington University in St. Louis, |
| 8 | * Beijing Institute of Technology, |
| 9 | * The University of Memphis |
| 10 | * |
| 11 | * This file is part of NFD (Named Data Networking Forwarding Daemon). |
| 12 | * See AUTHORS.md for complete list of NFD authors and contributors. |
| 13 | * |
| 14 | * NFD is free software: you can redistribute it and/or modify it under the terms |
| 15 | * of the GNU General Public License as published by the Free Software Foundation, |
| 16 | * either version 3 of the License, or (at your option) any later version. |
| 17 | * |
| 18 | * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; |
| 19 | * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR |
| 20 | * PURPOSE. See the GNU General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License along with |
| 23 | * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>. |
| 24 | **/ |
| 25 | |
| 26 | #ifndef NFD_DAEMON_FW_RTT_ESTIMATOR_HPP |
| 27 | #define NFD_DAEMON_FW_RTT_ESTIMATOR_HPP |
| 28 | |
| 29 | #include "common.hpp" |
| 30 | |
| 31 | namespace nfd { |
| 32 | |
| 33 | /** |
| 34 | * \brief implements the Mean-Deviation RTT estimator |
| 35 | * |
| 36 | * reference: ns3::RttMeanDeviation |
| 37 | * |
| 38 | * This RttEstimator algorithm is designed for TCP, which is a continuous stream. |
| 39 | * NDN Interest-Data traffic is not always a continuous stream, |
| 40 | * so NDN may need a different RttEstimator. |
| 41 | * The design of a more suitable RttEstimator is a research question. |
| 42 | */ |
| 43 | class RttEstimator |
| 44 | { |
| 45 | public: |
| 46 | typedef time::microseconds Duration; |
| 47 | |
| 48 | static Duration |
| 49 | getInitialRtt(void) |
| 50 | { |
| 51 | return time::seconds(1); |
| 52 | } |
| 53 | |
| 54 | RttEstimator(uint16_t maxMultiplier = 16, |
| 55 | Duration minRto = time::milliseconds(1), |
| 56 | double gain = 0.1); |
| 57 | |
| 58 | void |
| 59 | addMeasurement(Duration measure); |
| 60 | |
| 61 | void |
| 62 | incrementMultiplier(); |
| 63 | |
| 64 | void |
| 65 | doubleMultiplier(); |
| 66 | |
| 67 | Duration |
| 68 | computeRto() const; |
| 69 | |
| 70 | private: |
| 71 | uint16_t m_maxMultiplier; |
| 72 | double m_minRto; |
| 73 | |
| 74 | double m_rtt; |
| 75 | double m_gain; |
| 76 | double m_variance; |
| 77 | uint16_t m_multiplier; |
| 78 | uint32_t m_nSamples; |
| 79 | }; |
| 80 | |
| 81 | } // namespace nfd |
| 82 | |
| 83 | #endif // NFD_DAEMON_FW_RTT_ESTIMATOR_HPP |