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/*
* Copyright (c) 2017-2021 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.
*/
#pragma once
#include <hicn/transport/config.h>
#include <hicn/transport/core/asio_wrapper.h>
#include <hicn/transport/core/content_object.h>
#include <hicn/transport/core/name.h>
#include <protocols/indexer.h>
#include <protocols/rtc/rtc_consts.h>
#include <protocols/rtc/rtc_state.h>
#include <functional>
#include <map>
#include <unordered_map>
namespace transport {
namespace protocol {
namespace rtc {
class RTCLossDetectionAndRecovery
: public std::enable_shared_from_this<RTCLossDetectionAndRecovery> {
struct rtx_state_ {
uint64_t first_send_;
uint64_t next_send_;
uint32_t rtx_count_;
};
using rtxState = struct rtx_state_;
using SendRtxCallback = std::function<void(uint32_t)>;
public:
RTCLossDetectionAndRecovery(Indexer *indexer, SendRtxCallback &&callback,
asio::io_service &io_service);
~RTCLossDetectionAndRecovery();
void setState(std::shared_ptr<RTCState> state) { state_ = state; }
void setFecParams(uint32_t n, uint32_t k) {
n_ = n;
k_ = k;
}
void turnOnRTX();
void turnOffRTX();
bool isRtxOn() { return rtx_on_; }
void onNewRound(bool in_sync);
void onTimeout(uint32_t seq);
void onPacketRecoveredFec(uint32_t seq);
void onDataPacketReceived(const core::ContentObject &content_object);
void onNackPacketReceived(const core::ContentObject &nack);
void onProbePacketReceived(const core::ContentObject &probe);
void clear();
bool isRtx(uint32_t seq) {
if (rtx_state_.find(seq) != rtx_state_.end()) return true;
return false;
}
private:
void addToRetransmissions(uint32_t start, uint32_t stop);
uint64_t computeNextSend(uint32_t seq, bool new_rtx);
void retransmit();
void scheduleNextRtx();
bool deleteRtx(uint32_t seq);
void scheduleSentinelTimer(uint64_t expires_from_now);
void sentinelTimer();
uint32_t computeFecPacketsToAsk(bool in_sync);
uint64_t getNow() {
using namespace std::chrono;
uint64_t now =
duration_cast<milliseconds>(steady_clock::now().time_since_epoch())
.count();
return now;
}
// this map keeps track of the retransmitted interest, ordered from the oldest
// to the newest one. the state contains the timer of the first send of the
// interest (from pendingIntetests_), the timer of the next send (key of the
// multimap) and the number of rtx
std::map<uint32_t, rtxState> rtx_state_;
// this map stored the rtx by timer. The key is the time at which the rtx
// should be sent, and the val is the interest seq number
std::multimap<uint64_t, uint32_t> rtx_timers_;
// lost packets that will be recovered with fec
std::unordered_set<uint32_t> recover_with_fec_;
bool rtx_on_;
bool fec_on_;
uint64_t next_rtx_timer_;
uint64_t last_event_;
uint64_t sentinel_timer_interval_;
// fec params
uint32_t n_;
uint32_t k_;
std::unique_ptr<asio::steady_timer> timer_;
std::unique_ptr<asio::steady_timer> sentinel_timer_;
std::shared_ptr<RTCState> state_;
Indexer *indexer_;
SendRtxCallback send_rtx_callback_;
};
} // end namespace rtc
} // end namespace protocol
} // end namespace transport
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