solanaceae_ngc_ft1/solanaceae/ngc_ft1/cubic.cpp

63 lines
1.3 KiB
C++

#include "./cubic.hpp"
#include <cmath>
#include <iostream>
float CUBIC::getCWnD(void) const {
const double K = cbrt(
(_window_max * (1. - BETA)) / SCALING_CONSTANT
);
const double time_since_reduction = getTimeNow() - _time_point_reduction;
const double TK = time_since_reduction - K;
const double cwnd =
SCALING_CONSTANT
* TK * TK * TK // TK^3
+ _window_max
;
#if 0
std::cout
<< "K:" << K
<< " ts:" << time_since_reduction
<< " TK:" << TK
<< " cwnd:" << cwnd
<< " rtt:" << getCurrentDelay()
<< "\n"
;
#endif
return std::max<float>(cwnd, 2.f * MAXIMUM_SEGMENT_SIZE);
}
void CUBIC::onCongestion(void) {
if (getTimeNow() - _time_point_reduction >= getCurrentDelay()) {
const auto current_cwnd = getCWnD();
_time_point_reduction = getTimeNow();
_window_max = current_cwnd;
std::cout << "CONGESTION! cwnd:" << current_cwnd << "\n";
}
}
size_t CUBIC::canSend(void) {
const auto fspace_pkgs = FlowOnly::canSend();
if (fspace_pkgs == 0u) {
return 0u;
}
const int64_t cspace_bytes = getCWnD() - _in_flight_bytes;
if (cspace_bytes < MAXIMUM_SEGMENT_DATA_SIZE) {
return 0u;
}
// limit to whole packets
size_t cspace_pkgs = std::floor(cspace_bytes / MAXIMUM_SEGMENT_DATA_SIZE) * MAXIMUM_SEGMENT_DATA_SIZE;
return std::min(cspace_pkgs, fspace_pkgs);
}