1 files changed, 57 insertions, 0 deletions
diff --git a/libtransport/src/hicn/transport/protocols/vegas_rto_estimator.cc b/libtransport/src/hicn/transport/protocols/vegas_rto_estimator.cc
new file mode 100755
index 000000000..f5f797bbe
--- /dev/null
+++ b/libtransport/src/hicn/transport/protocols/vegas_rto_estimator.cc
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <hicn/transport/interfaces/socket_options_default_values.h>
+#include <hicn/transport/protocols/vegas_rto_estimator.h>
+
+#include <algorithm>
+#include <cmath>
+
+namespace transport {
+
+namespace protocol {
+
+using namespace interface;
+
+RtoEstimator::RtoEstimator(Duration min_rto)
+    : smoothed_rtt_(RtoEstimator::getInitialRtt().count()),
+      rtt_variation_(0),
+      first_measurement_(true),
+      last_rto_(min_rto.count()) {}
+
+void RtoEstimator::addMeasurement(Duration rtt) {
+  double duration = static_cast<double>(rtt.count());
+  if (first_measurement_) {
+    smoothed_rtt_ = duration;
+    rtt_variation_ = duration / 2;
+    first_measurement_ = false;
+  } else {
+    rtt_variation_ = (1 - default_values::beta) * rtt_variation_ +
+                     default_values::beta * std::abs(smoothed_rtt_ - duration);
+    smoothed_rtt_ = (1 - default_values::alpha) * smoothed_rtt_ +
+                    default_values::alpha * duration;
+  }
+}
+
+RtoEstimator::Duration RtoEstimator::computeRto() const {
+  double rto = smoothed_rtt_ +
+               std::max(double(default_values::clock_granularity.count()),
+                        default_values::k* rtt_variation_);
+  return Duration(static_cast<Duration::rep>(rto));
+}
+
+}  // end namespace protocol
+
+}  // end namespace transport
+\ No newline at end of file