Initial Commit: libicnet

Change-Id: I10a72cb0d84b76553a85c168416b847f6a4ff5f6
Signed-off-by: Mauro Sardara <msardara+fdio@cisco.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/icnet/transport/icnet_transport_vegas_rto_estimator.cc b/icnet/transport/icnet_transport_vegas_rto_estimator.cc
new file mode 100644
index 00000000..889a6bd3
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+++ b/icnet/transport/icnet_transport_vegas_rto_estimator.cc
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2017 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 "icnet_transport_vegas_rto_estimator.h"
+#include "icnet_socket_options_default_values.h"
+
+namespace icnet {
+
+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 icnet
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