1 files changed, 137 insertions, 0 deletions
diff --git a/lib/ngtcp2_rst.c b/lib/ngtcp2_rst.c
new file mode 100644
index 0000000..7b50f98
--- /dev/null
+++ b/lib/ngtcp2_rst.c
@@ -0,0 +1,137 @@
+/*
+ * ngtcp2
+ *
+ * Copyright (c) 2019 ngtcp2 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include "ngtcp2_rst.h"
+
+#include <assert.h>
+
+#include "ngtcp2_rtb.h"
+#include "ngtcp2_cc.h"
+#include "ngtcp2_macro.h"
+
+void ngtcp2_rs_init(ngtcp2_rs *rs) {
+  rs->interval = UINT64_MAX;
+  rs->delivered = 0;
+  rs->prior_delivered = 0;
+  rs->prior_ts = 0;
+  rs->tx_in_flight = 0;
+  rs->lost = 0;
+  rs->prior_lost = 0;
+  rs->send_elapsed = 0;
+  rs->ack_elapsed = 0;
+  rs->is_app_limited = 0;
+}
+
+void ngtcp2_rst_init(ngtcp2_rst *rst) {
+  ngtcp2_rs_init(&rst->rs);
+  ngtcp2_window_filter_init(&rst->wf, 12);
+  rst->delivered = 0;
+  rst->delivered_ts = 0;
+  rst->first_sent_ts = 0;
+  rst->app_limited = 0;
+  rst->next_round_delivered = 0;
+  rst->round_count = 0;
+  rst->is_cwnd_limited = 0;
+  rst->lost = 0;
+}
+
+void ngtcp2_rst_on_pkt_sent(ngtcp2_rst *rst, ngtcp2_rtb_entry *ent,
+                            const ngtcp2_conn_stat *cstat) {
+  if (cstat->bytes_in_flight == 0) {
+    rst->first_sent_ts = rst->delivered_ts = ent->ts;
+  }
+  ent->rst.first_sent_ts = rst->first_sent_ts;
+  ent->rst.delivered_ts = rst->delivered_ts;
+  ent->rst.delivered = rst->delivered;
+  ent->rst.is_app_limited = rst->app_limited != 0;
+  ent->rst.tx_in_flight = cstat->bytes_in_flight + ent->pktlen;
+  ent->rst.lost = rst->lost;
+}
+
+int ngtcp2_rst_on_ack_recv(ngtcp2_rst *rst, ngtcp2_conn_stat *cstat,
+                           uint64_t pkt_delivered) {
+  ngtcp2_rs *rs = &rst->rs;
+  uint64_t rate;
+
+  if (rst->app_limited && rst->delivered > rst->app_limited) {
+    rst->app_limited = 0;
+  }
+
+  if (pkt_delivered >= rst->next_round_delivered) {
+    rst->next_round_delivered = pkt_delivered;
+    ++rst->round_count;
+  }
+
+  if (rs->prior_ts == 0) {
+    return 0;
+  }
+
+  rs->interval = ngtcp2_max(rs->send_elapsed, rs->ack_elapsed);
+
+  rs->delivered = rst->delivered - rs->prior_delivered;
+  rs->lost = rst->lost - rs->prior_lost;
+
+  if (rs->interval < cstat->min_rtt) {
+    rs->interval = UINT64_MAX;
+    return 0;
+  }
+
+  if (!rs->interval) {
+    return 0;
+  }
+
+  rate = rs->delivered * NGTCP2_SECONDS / rs->interval;
+
+  if (rate > ngtcp2_window_filter_get_best(&rst->wf) || !rst->app_limited) {
+    ngtcp2_window_filter_update(&rst->wf, rate, rst->round_count);
+    cstat->delivery_rate_sec = ngtcp2_window_filter_get_best(&rst->wf);
+  }
+
+  return 0;
+}
+
+void ngtcp2_rst_update_rate_sample(ngtcp2_rst *rst, const ngtcp2_rtb_entry *ent,
+                                   ngtcp2_tstamp ts) {
+  ngtcp2_rs *rs = &rst->rs;
+
+  rst->delivered += ent->pktlen;
+  rst->delivered_ts = ts;
+
+  if (ent->rst.delivered > rs->prior_delivered) {
+    rs->prior_delivered = ent->rst.delivered;
+    rs->prior_ts = ent->rst.delivered_ts;
+    rs->is_app_limited = ent->rst.is_app_limited;
+    rs->send_elapsed = ent->ts - ent->rst.first_sent_ts;
+    rs->ack_elapsed = rst->delivered_ts - ent->rst.delivered_ts;
+    rs->tx_in_flight = ent->rst.tx_in_flight;
+    rs->prior_lost = ent->rst.lost;
+    rst->first_sent_ts = ent->ts;
+  }
+}
+
+void ngtcp2_rst_update_app_limited(ngtcp2_rst *rst, ngtcp2_conn_stat *cstat) {
+  (void)rst;
+  (void)cstat;
+  /* TODO Not implemented */
+}