| Junxiao Shi | 192af1f | 2015-01-13 23:19:39 -0700 | [diff] [blame^] | 1 | /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */ |
| 2 | /** |
| 3 | * Copyright (c) 2014-2015, 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 | #include "retransmission-suppression.hpp" |
| 27 | |
| 28 | namespace nfd { |
| 29 | namespace fw { |
| 30 | |
| 31 | /// \todo don't use fixed interval; make it adaptive or use exponential back-off #1913 |
| 32 | const time::milliseconds RetransmissionSuppression::MIN_RETRANSMISSION_INTERVAL(100); |
| 33 | |
| 34 | RetransmissionSuppression::Result |
| 35 | RetransmissionSuppression::decide(const Face& inFace, const Interest& interest, |
| 36 | const pit::Entry& pitEntry) |
| 37 | { |
| 38 | bool isNewPitEntry = !pitEntry.hasUnexpiredOutRecords(); |
| 39 | if (isNewPitEntry) { |
| 40 | return NEW; |
| 41 | } |
| 42 | |
| 43 | // when was the last outgoing Interest? |
| 44 | const pit::OutRecordCollection& outRecords = pitEntry.getOutRecords(); |
| 45 | pit::OutRecordCollection::const_iterator lastOutgoing = std::max_element( |
| 46 | outRecords.begin(), outRecords.end(), |
| 47 | [] (const pit::OutRecord& a, const pit::OutRecord& b) { |
| 48 | return a.getLastRenewed() < b.getLastRenewed(); |
| 49 | }); |
| 50 | BOOST_ASSERT(lastOutgoing != outRecords.end()); // otherwise it's new PIT entry |
| 51 | |
| 52 | time::steady_clock::TimePoint now = time::steady_clock::now(); |
| 53 | time::steady_clock::Duration sinceLastOutgoing = now - lastOutgoing->getLastRenewed(); |
| 54 | bool shouldSuppress = sinceLastOutgoing < MIN_RETRANSMISSION_INTERVAL; |
| 55 | return shouldSuppress ? SUPPRESS : FORWARD; |
| 56 | } |
| 57 | |
| 58 | } // namespace fw |
| 59 | } // namespace nfd |