fw: abstract retransmission suppression logic

Consumer retransmission suppression logic of best-route v2 strategy
is abstracted into RetransmissionSuppression class, so that it can
be reused in other strategies.

refs #2377

Change-Id: I7de2c2d0e60c5ad3467e24283e9b03bd03f65bdc
diff --git a/tests/daemon/fw/best-route-strategy2.cpp b/tests/daemon/fw/best-route-strategy2.cpp
index d956e9f..687bfcb 100644
--- a/tests/daemon/fw/best-route-strategy2.cpp
+++ b/tests/daemon/fw/best-route-strategy2.cpp
@@ -1,12 +1,12 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014,  Regents of the University of California,
- *                      Arizona Board of Regents,
- *                      Colorado State University,
- *                      University Pierre & Marie Curie, Sorbonne University,
- *                      Washington University in St. Louis,
- *                      Beijing Institute of Technology,
- *                      The University of Memphis
+ * Copyright (c) 2014-2015,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
  *
  * This file is part of NFD (Named Data Networking Forwarding Daemon).
  * See AUTHORS.md for complete list of NFD authors and contributors.
@@ -62,13 +62,13 @@
   shared_ptr<pit::Entry> pitEntry = pit.insert(*interest).first;
 
   const time::nanoseconds TICK = time::duration_cast<time::nanoseconds>(
-    fw::BestRouteStrategy2::MIN_RETRANSMISSION_INTERVAL * 0.01);
+    fw::RetransmissionSuppression::MIN_RETRANSMISSION_INTERVAL * 0.01);
   const time::nanoseconds RETRANSMISSION_10P = time::duration_cast<time::nanoseconds>(
-    fw::BestRouteStrategy2::MIN_RETRANSMISSION_INTERVAL * 0.1); // 10%
+    fw::RetransmissionSuppression::MIN_RETRANSMISSION_INTERVAL * 0.1); // 10%
   const time::nanoseconds RETRANSMISSION_70P = time::duration_cast<time::nanoseconds>(
-    fw::BestRouteStrategy2::MIN_RETRANSMISSION_INTERVAL * 0.7); // 70%
+    fw::RetransmissionSuppression::MIN_RETRANSMISSION_INTERVAL * 0.7); // 70%
   const time::nanoseconds RETRANSMISSION_2 = time::duration_cast<time::nanoseconds>(
-    fw::BestRouteStrategy2::MIN_RETRANSMISSION_INTERVAL * 2.0); // x2
+    fw::RetransmissionSuppression::MIN_RETRANSMISSION_INTERVAL * 2.0); // x2
 
   // first Interest goes to nexthop with lowest FIB cost,
   // however face1 is downstream so it cannot be used
@@ -99,7 +99,7 @@
     retxFrom4Evt = scheduler::schedule(RETRANSMISSION_10P, periodicalRetxFrom4);
   };
   periodicalRetxFrom4();
-  this->advanceClocks(TICK, fw::BestRouteStrategy2::MIN_RETRANSMISSION_INTERVAL * 16);
+  this->advanceClocks(TICK, fw::RetransmissionSuppression::MIN_RETRANSMISSION_INTERVAL * 16);
   scheduler::cancel(retxFrom4Evt);
 
   // nexthops for accepted retransmissions: follow FIB cost,
diff --git a/tests/daemon/fw/retransmission-suppression.cpp b/tests/daemon/fw/retransmission-suppression.cpp
new file mode 100644
index 0000000..c1ba968
--- /dev/null
+++ b/tests/daemon/fw/retransmission-suppression.cpp
@@ -0,0 +1,90 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NFD, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "fw/retransmission-suppression.hpp"
+#include "strategy-tester.hpp"
+
+#include "tests/test-common.hpp"
+#include "tests/daemon/face/dummy-face.hpp"
+
+namespace nfd {
+namespace tests {
+
+using fw::RetransmissionSuppression;
+
+BOOST_FIXTURE_TEST_SUITE(FwRetransmissionSuppression, UnitTestTimeFixture)
+
+BOOST_AUTO_TEST_CASE(Basic)
+{
+  Forwarder forwarder;
+  Pit& pit = forwarder.getPit();
+  RetransmissionSuppression rs;
+
+  shared_ptr<DummyFace> face1 = make_shared<DummyFace>();
+  shared_ptr<DummyFace> face2 = make_shared<DummyFace>();
+  shared_ptr<DummyFace> face3 = make_shared<DummyFace>();
+  forwarder.addFace(face1);
+  forwarder.addFace(face2);
+  forwarder.addFace(face3);
+
+  shared_ptr<Interest> interest = makeInterest("ndn:/0JiimvmxK8");
+  shared_ptr<pit::Entry> pitEntry = pit.insert(*interest).first;
+
+  const time::nanoseconds RETRANSMISSION_10P = time::duration_cast<time::nanoseconds>(
+    fw::RetransmissionSuppression::MIN_RETRANSMISSION_INTERVAL * 0.1);
+
+  // @ time 0
+  pitEntry->insertOrUpdateInRecord(face1, *interest);
+  BOOST_CHECK_EQUAL(rs.decide(*face1, *interest, *pitEntry), RetransmissionSuppression::NEW);
+  pitEntry->insertOrUpdateOutRecord(face3, *interest);
+
+  this->advanceClocks(RETRANSMISSION_10P, 5); // @ time 0.5 interval
+  pitEntry->insertOrUpdateInRecord(face1, *interest);
+  BOOST_CHECK_EQUAL(rs.decide(*face1, *interest, *pitEntry), RetransmissionSuppression::SUPPRESS);
+  pitEntry->insertOrUpdateInRecord(face2, *interest);
+  BOOST_CHECK_EQUAL(rs.decide(*face2, *interest, *pitEntry), RetransmissionSuppression::SUPPRESS);
+
+  this->advanceClocks(RETRANSMISSION_10P, 6); // @ time 1.1 interval
+  pitEntry->insertOrUpdateInRecord(face2, *interest);
+  BOOST_CHECK_EQUAL(rs.decide(*face2, *interest, *pitEntry), RetransmissionSuppression::FORWARD);
+  // but strategy decides not to forward
+
+  this->advanceClocks(RETRANSMISSION_10P, 1); // @ time 1.2 interval
+  pitEntry->insertOrUpdateInRecord(face1, *interest);
+  BOOST_CHECK_EQUAL(rs.decide(*face1, *interest, *pitEntry), RetransmissionSuppression::FORWARD);
+  // retransmission suppress shall still give clearance for forwarding
+  pitEntry->insertOrUpdateOutRecord(face3, *interest); // and strategy forwards
+
+  this->advanceClocks(RETRANSMISSION_10P, 2); // @ time 1.4 interval
+  pitEntry->insertOrUpdateInRecord(face1, *interest);
+  BOOST_CHECK_EQUAL(rs.decide(*face1, *interest, *pitEntry), RetransmissionSuppression::SUPPRESS);
+  pitEntry->insertOrUpdateInRecord(face2, *interest);
+  BOOST_CHECK_EQUAL(rs.decide(*face2, *interest, *pitEntry), RetransmissionSuppression::SUPPRESS);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+} // namespace tests
+} // namespace nfd