catchunks: Implement CUBIC window adaptation

Also increase the RTT estimator multiplier k to 8.

Change-Id: I68c5096ac0da854f071bab5f7519b1c144f20ca1
refs: #4861
diff --git a/tools/chunks/catchunks/pipeline-interests-aimd.cpp b/tools/chunks/catchunks/pipeline-interests-aimd.cpp
new file mode 100644
index 0000000..0292714
--- /dev/null
+++ b/tools/chunks/catchunks/pipeline-interests-aimd.cpp
@@ -0,0 +1,69 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2016-2019, Regents of the University of California,
+ *                          Colorado State University,
+ *                          University Pierre & Marie Curie, Sorbonne University.
+ *
+ * This file is part of ndn-tools (Named Data Networking Essential Tools).
+ * See AUTHORS.md for complete list of ndn-tools authors and contributors.
+ *
+ * ndn-tools 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.
+ *
+ * ndn-tools 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
+ * ndn-tools, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ *
+ * @author Shuo Yang
+ * @author Weiwei Liu
+ * @author Chavoosh Ghasemi
+ * @author Klaus Schneider
+ */
+
+#include "pipeline-interests-aimd.hpp"
+
+#include <cmath>
+
+namespace ndn {
+namespace chunks {
+
+PipelineInterestsAimd::PipelineInterestsAimd(Face& face, RttEstimator& rttEstimator,
+                                             const Options& options)
+  : PipelineInterestsAdaptive(face, rttEstimator, options)
+{
+  if (options.isVerbose) {
+    std::cerr << options;
+  }
+}
+
+void
+PipelineInterestsAimd::increaseWindow()
+{
+  if (m_cwnd < m_ssthresh) {
+    m_cwnd += m_options.aiStep; // additive increase
+  }
+  else {
+    m_cwnd += m_options.aiStep / std::floor(m_cwnd); // congestion avoidance
+  }
+
+  emitSignal(afterCwndChange, time::steady_clock::now() - getStartTime(), m_cwnd);
+}
+
+void
+PipelineInterestsAimd::decreaseWindow()
+{
+  // please refer to RFC 5681, Section 3.1 for the rationale behind it
+  m_ssthresh = std::max(MIN_SSTHRESH, m_cwnd * m_options.mdCoef); // multiplicative decrease
+  m_cwnd = m_options.resetCwndToInit ? m_options.initCwnd : m_ssthresh;
+
+  emitSignal(afterCwndChange, time::steady_clock::now() - getStartTime(), m_cwnd);
+}
+
+} // namespace chunks
+} // namespace ndn