fw: fix and simplify enumeration logic in Forwarder::onNewNextHop()

Also remove Strategy::enableNewNextHopTrigger(). Strategies can already
opt-in by overriding afterNewNextHop(), there is no need for a separate
enablement flag.

Refs: #4931
Change-Id: Ifcbdbc7e954bd20d9969fd99882a2a9aebbc8fcc
diff --git a/tests/daemon/fw/forwarder.t.cpp b/tests/daemon/fw/forwarder.t.cpp
index 77db2c8..f3f7c63 100644
--- a/tests/daemon/fw/forwarder.t.cpp
+++ b/tests/daemon/fw/forwarder.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020,  Regents of the University of California,
+ * Copyright (c) 2014-2021,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -698,6 +698,96 @@
   BOOST_CHECK_EQUAL(forwarder.getCounters().nUnsolicitedData, 1);
 }
 
+BOOST_AUTO_TEST_CASE(NewNextHop)
+{
+  auto face1 = addFace();
+  auto face2 = addFace();
+  auto face3 = addFace();
+  auto face4 = addFace();
+
+  auto& strategy = choose<DummyStrategy>(forwarder, "/A", DummyStrategy::getStrategyName());
+
+  Fib& fib = forwarder.getFib();
+  Pit& pit = forwarder.getPit();
+
+  // fib: "/", "/A/B", "/A/B/C/D/E"
+  fib::Entry* entry = fib.insert("/").first;
+  fib.addOrUpdateNextHop(*entry, *face1, 100);
+  entry = fib.insert("/A/B").first;
+  fib.addOrUpdateNextHop(*entry, *face2, 0);
+  entry = fib.insert("/A/B/C/D/E").first;
+  fib.addOrUpdateNextHop(*entry, *face3, 0);
+
+  // pit: "/A", "/A/B/C", "/A/B/Z"
+  auto interest1 = makeInterest("/A");
+  auto pit1 = pit.insert(*interest1).first;
+  pit1->insertOrUpdateInRecord(*face3, *interest1);
+  auto interest2 = makeInterest("/A/B/C");
+  auto pit2 = pit.insert(*interest2).first;
+  pit2->insertOrUpdateInRecord(*face3, *interest2);
+  auto interest3 = makeInterest("/A/B/Z");
+  auto pit3 = pit.insert(*interest3).first;
+  pit3->insertOrUpdateInRecord(*face3, *interest3);
+
+  // new nexthop for "/"
+  entry = fib.insert("/").first;
+  fib.addOrUpdateNextHop(*entry, *face2, 50);
+
+  // /A     --> triggered
+  // /A/B/C --> not triggered
+  // /A/B/Z --> not triggered
+  BOOST_TEST_REQUIRE(strategy.afterNewNextHopCalls.size() == 1);
+  BOOST_TEST(strategy.afterNewNextHopCalls[0] == "/A");
+  strategy.afterNewNextHopCalls.clear();
+
+  // new nexthop for "/A"
+  entry = fib.insert("/A").first;
+  fib.addOrUpdateNextHop(*entry, *face4, 50);
+
+  // /A     --> triggered
+  // /A/B/C --> not triggered
+  // /A/B/Z --> not triggered
+  BOOST_TEST_REQUIRE(strategy.afterNewNextHopCalls.size() == 1);
+  BOOST_TEST(strategy.afterNewNextHopCalls[0] == "/A");
+  strategy.afterNewNextHopCalls.clear();
+
+  // new nexthop for "/A/B"
+  entry = fib.insert("/A/B").first;
+  fib.addOrUpdateNextHop(*entry, *face4, 0);
+
+  // /A     --> not triggered
+  // /A/B/C --> triggered
+  // /A/B/Z --> triggered
+  BOOST_TEST_REQUIRE(strategy.afterNewNextHopCalls.size() == 2);
+  BOOST_TEST(strategy.afterNewNextHopCalls[0] == "/A/B/C");
+  BOOST_TEST(strategy.afterNewNextHopCalls[1] == "/A/B/Z");
+  strategy.afterNewNextHopCalls.clear();
+
+  // new nexthop for "/A/B/C/D"
+  entry = fib.insert("/A/B/C/D").first;
+  fib.addOrUpdateNextHop(*entry, *face1, 0);
+
+  // nothing triggered
+  BOOST_TEST(strategy.afterNewNextHopCalls.size() == 0);
+
+  // create a second pit entry for /A
+  auto interest4 = makeInterest("/A");
+  interest4->setMustBeFresh(true);
+  auto pit4 = pit.insert(*interest4).first;
+  pit4->insertOrUpdateInRecord(*face3, *interest4);
+
+  // new nexthop for "/A"
+  entry = fib.insert("/A").first;
+  fib.addOrUpdateNextHop(*entry, *face1, 0);
+
+  // /A     --> triggered twice
+  // /A/B/C --> not triggered
+  // /A/B/Z --> not triggered
+  BOOST_TEST_REQUIRE(strategy.afterNewNextHopCalls.size() == 2);
+  BOOST_TEST(strategy.afterNewNextHopCalls[0] == "/A");
+  BOOST_TEST(strategy.afterNewNextHopCalls[1] == "/A");
+}
+
 BOOST_AUTO_TEST_SUITE_END() // TestForwarder
 BOOST_AUTO_TEST_SUITE_END() // Fw
 
diff --git a/tests/daemon/fw/strategy-newnexthop.t.cpp b/tests/daemon/fw/strategy-newnexthop.t.cpp
deleted file mode 100644
index 282e74f..0000000
--- a/tests/daemon/fw/strategy-newnexthop.t.cpp
+++ /dev/null
@@ -1,163 +0,0 @@
-/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/*
- * Copyright (c) 2014-2019,  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/forwarder.hpp"
-#include "common/global.hpp"
-
-#include "tests/test-common.hpp"
-#include "tests/daemon/global-io-fixture.hpp"
-#include "tests/daemon/face/dummy-face.hpp"
-#include "choose-strategy.hpp"
-#include "dummy-strategy.hpp"
-
-namespace nfd {
-namespace tests {
-
-class StrategyNewNextHopFixture : public GlobalIoTimeFixture
-{
-protected:
-  template<typename ...Args>
-  shared_ptr<DummyFace>
-  addFace(Args&&... args)
-  {
-    auto face = make_shared<DummyFace>(std::forward<Args>(args)...);
-    faceTable.add(face);
-    return face;
-  }
-
-protected:
-  FaceTable faceTable;
-  Forwarder forwarder{faceTable};
-};
-
-BOOST_AUTO_TEST_SUITE(Fw)
-BOOST_FIXTURE_TEST_SUITE(TestStrategyNewNextHop, StrategyNewNextHopFixture)
-
-BOOST_AUTO_TEST_CASE(AfterNewNextHop1)
-{
-  auto face1 = addFace();
-  auto face2 = addFace();
-  auto face3 = addFace();
-
-  DummyStrategy& strategy = choose<DummyStrategy>(forwarder, "/A", DummyStrategy::getStrategyName());
-  StrategyChoice& sc = forwarder.getStrategyChoice();
-  sc.insert(Name("/A/B"), strategy.getStrategyName());
-  sc.insert(Name("/A/B/C"), strategy.getStrategyName());
-
-  strategy.enableNewNextHopTrigger(true);
-
-  Fib& fib = forwarder.getFib();
-  Pit& pit = forwarder.getPit();
-
-  // fib: "/", "/A/B"
-  fib::Entry* entry = fib.insert("/").first;
-  fib.addOrUpdateNextHop(*entry, *face1, 0);
-  entry = fib.insert("/A/B").first;
-  fib.addOrUpdateNextHop(*entry, *face1, 0);
-
-  // pit: "/A", "/A/B/C"
-  auto interest1 = makeInterest("/A");
-  shared_ptr<pit::Entry> pit1 = pit.insert(*interest1).first;
-  pit1->insertOrUpdateInRecord(*face3, *interest1);
-  auto interest2 = makeInterest("/A/B/C");
-  shared_ptr<pit::Entry> pit2 = pit.insert(*interest2).first;
-  pit2->insertOrUpdateInRecord(*face3, *interest2);
-  // new nexthop for "/"
-  entry = fib.insert("/").first;
-  fib.addOrUpdateNextHop(*entry, *face2, 0);
-
-  // /A --> triggered, /A/B --> not triggered, /A/B/C --> not triggered
-  BOOST_REQUIRE_EQUAL(strategy.afterNewNextHopCalls.size(), 1);
-  BOOST_CHECK_EQUAL(strategy.afterNewNextHopCalls[0], Name("/A"));
-}
-
-BOOST_AUTO_TEST_CASE(AfterNewNextHop2)
-{
-  auto face1 = addFace();
-  auto face2 = addFace();
-  auto face3 = addFace();
-
-  DummyStrategy& strategy = choose<DummyStrategy>(forwarder, "/A", DummyStrategy::getStrategyName());
-  StrategyChoice& sc = forwarder.getStrategyChoice();
-  sc.insert(Name("/A/B"), strategy.getStrategyName());
-  sc.insert(Name("/A/B/C"), strategy.getStrategyName());
-
-  strategy.enableNewNextHopTrigger(true);
-
-  Fib& fib = forwarder.getFib();
-  Pit& pit = forwarder.getPit();
-
-  // fib: "/", "/A/B"
-  fib::Entry* entry = fib.insert("/").first;
-  fib.addOrUpdateNextHop(*entry, *face1, 0);
-  entry = fib.insert("/A/B").first;
-  fib.addOrUpdateNextHop(*entry, *face1, 0);
-
-  // pit: "/A", "/A/B/C"
-  auto interest1 = makeInterest("/A");
-  shared_ptr<pit::Entry> pit1 = pit.insert(*interest1).first;
-  pit1->insertOrUpdateInRecord(*face3, *interest1);
-  auto interest2 = makeInterest("/A/B");
-  shared_ptr<pit::Entry> pit2 = pit.insert(*interest2).first;
-  pit2->insertOrUpdateInRecord(*face3, *interest2);
-  // new nexthop for "/"
-  entry = fib.insert("/").first;
-  fib.addOrUpdateNextHop(*entry, *face2, 0);
-
-  // /A --> triggered, /A/B --> not triggered, /A/B/C --> not triggered
-  BOOST_REQUIRE_EQUAL(strategy.afterNewNextHopCalls.size(), 1);
-  BOOST_CHECK_EQUAL(strategy.afterNewNextHopCalls[0], Name("/A"));
-}
-
-BOOST_AUTO_TEST_CASE(DisableTrigger)
-{
-  auto face1 = addFace();
-  auto face2 = addFace();
-  auto face3 = addFace();
-
-  DummyStrategy& strategy = choose<DummyStrategy>(forwarder, "/A", DummyStrategy::getStrategyName());
-  strategy.enableNewNextHopTrigger(false);
-
-  Fib& fib = forwarder.getFib();
-  Pit& pit = forwarder.getPit();
-
-  fib::Entry* entry = fib.insert("/").first;
-  fib.addOrUpdateNextHop(*entry, *face1, 0);
-
-  auto interest1 = makeInterest("/A");
-  shared_ptr<pit::Entry> pit1 = pit.insert(*interest1).first;
-  pit1->insertOrUpdateInRecord(*face3, *interest1);
-  // new nexthop for "/A"
-  entry = fib.insert("/A").first;
-  fib.addOrUpdateNextHop(*entry, *face2, 0);
-
-  BOOST_CHECK_EQUAL(strategy.afterNewNextHopCalls.size(), 0);
-}
-
-BOOST_AUTO_TEST_SUITE_END() // TestStrategyNewNextHop
-BOOST_AUTO_TEST_SUITE_END() // Fw
-
-} // namespace tests
-} // namespace nfd