diff options
Diffstat (limited to 'libtransport/src/protocols/rtc/rtc_rs_delay.cc')
-rw-r--r-- | libtransport/src/protocols/rtc/rtc_rs_delay.cc | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/libtransport/src/protocols/rtc/rtc_rs_delay.cc b/libtransport/src/protocols/rtc/rtc_rs_delay.cc new file mode 100644 index 000000000..7d7a01133 --- /dev/null +++ b/libtransport/src/protocols/rtc/rtc_rs_delay.cc @@ -0,0 +1,147 @@ +/* + * Copyright (c) 2021 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 <glog/logging.h> +#include <protocols/rtc/rtc_consts.h> +#include <protocols/rtc/rtc_rs_delay.h> + +namespace transport { + +namespace protocol { + +namespace rtc { + +RecoveryStrategyDelayBased::RecoveryStrategyDelayBased( + Indexer *indexer, SendRtxCallback &&callback, asio::io_service &io_service, + interface::RtcTransportRecoveryStrategies rs_type, + interface::StrategyCallback &&external_callback) + : RecoveryStrategy(indexer, std::move(callback), io_service, true, false, + rs_type, + std::move(external_callback)), // start with rtx + congestion_state_(false), + probing_state_(false), + switch_rounds_(0) {} + +RecoveryStrategyDelayBased::RecoveryStrategyDelayBased(RecoveryStrategy &&rs) + : RecoveryStrategy(std::move(rs)) { + setRtxFec(true, false); + // we have to re-init congestion and + // probing + switch_rounds_ = 0; + congestion_state_ = false; + probing_state_ = false; +} + +RecoveryStrategyDelayBased::~RecoveryStrategyDelayBased() {} + +void RecoveryStrategyDelayBased::turnOnRecovery() { + recovery_on_ = true; + uint64_t rtt = state_->getMinRTT(); + uint32_t fec_to_ask = computeFecPacketsToAsk(); + if (rtt > MAX_RTT_BEFORE_FEC && fec_to_ask > 0) { + // we need to start FEC (see fec only strategy for more details) + setRtxFec(true, true); + rtx_during_fec_ = 1; // avoid to stop fec + indexer_->setNFec(fec_to_ask); + } else { + // use RTX + setRtxFec(true, false); + switch_rounds_ = 0; + } +} + +void RecoveryStrategyDelayBased::softSwitchToFec(uint32_t fec_to_ask) { + if (fec_to_ask == 0) { + setRtxFec(true, false); + switch_rounds_ = 0; + } else { + switch_rounds_++; + if (switch_rounds_ >= ((RTC_INTEREST_LIFETIME / ROUND_LEN) * 2) && + rtx_during_fec_ != 0) { // go to fec only if it is needed (RTX are on) + setRtxFec(false, true); + } else { + setRtxFec(true, true); + } + } +} + +void RecoveryStrategyDelayBased::onNewRound(bool in_sync) { + if (!recovery_on_) { + // disable fec so that no extra packet will be sent + // for rtx we check if recovery is on in newPacketLoss + setRtxFec(true, false); + indexer_->setNFec(0); + return; + } + + uint64_t rtt = state_->getAvgRTT(); + + // XXX at the moment we are not looking at congestion events + // bool congestion = rc_->inCongestionState(); + + if ((!fec_on_ && rtt >= MAX_RTT_BEFORE_FEC) || + (fec_on_ && rtt > (MAX_RTT_BEFORE_FEC - 10))) { + // switch from rtx to fec or keep use fec. Notice that if some rtx are + // waiting to be scheduled, they will be sent normally, but no new rtx will + // be created if the loss rate is 0 keep to use RTX. + uint32_t fec_to_ask = computeFecPacketsToAsk(); + softSwitchToFec(fec_to_ask); + if (rtx_during_fec_ == 0) // if we do not send any RTX the losses + // registered may be due to jitter + indexer_->setNFec(0); + else + indexer_->setNFec(fec_to_ask); + return; + } + + if ((fec_on_ && rtt <= (MAX_RTT_BEFORE_FEC - 10)) || + (!rtx_on_ && rtt <= MAX_RTT_BEFORE_FEC)) { + // turn on rtx + softSwitchToFec(0); + indexer_->setNFec(0); + return; + } +} + +void RecoveryStrategyDelayBased::newPacketLoss(uint32_t seq) { + if (rtx_on_ && recovery_on_) { + addNewRtx(seq, false); + } else { + if (!state_->isPending(seq) && !indexer_->isFec(seq)) { + addNewRtx(seq, true); + } else { + recover_with_fec_.insert(seq); + state_->onPossibleLossWithNoRtx(seq); + } + } +} + +void RecoveryStrategyDelayBased::receivedPacket(uint32_t seq) { + removePacketState(seq); +} + +void RecoveryStrategyDelayBased::probing() { + // TODO + // for the moment ask for all fec and exit the probing phase + probing_state_ = false; + setRtxFec(false, true); + indexer_->setNFec(computeFecPacketsToAsk()); +} + +} // end namespace rtc + +} // end namespace protocol + +} // end namespace transport |