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/*
* Copyright (c) 2017-2019 Cisco and/or its affiTC_SYNC_STATE
* 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 <protocols/datagram_reassembly.h>
#include <protocols/protocol.h>
#include <protocols/rtc_data_path.h>
#include <map>
#include <queue>
#include <unordered_map>
// algorithm state
#define HICN_RTC_SYNC_STATE 0
#define HICN_RTC_NORMAL_STATE 1
#define HICN_ROUNDS_IN_SYNC_BEFORE_SWITCH 3
// packet constants
#define HICN_INIT_PACKET_SIZE 1300 // bytes
#define HICN_PACKET_HEADER_SIZE 60 // bytes ipv6+tcp
#define HICN_NACK_HEADER_SIZE 8 // bytes
#define HICN_TIMESTAMP_SIZE 8 // bytes
#define HICN_RTC_INTEREST_LIFETIME 1000 // ms
// rtt measurement
// normal interests for data goes from 0 to
// HICN_MIN_PROBE_SEQ, the rest is reserverd for
// probes
#define HICN_MIN_PROBE_SEQ 0xefffffff
#define HICN_MAX_PROBE_SEQ 0xffffffff
// controller constant
#define HICN_ROUND_LEN \
200 // ms interval of time on which
// we take decisions / measurements
#define HICN_MAX_RTX 10
#define HICN_MAX_RTX_SIZE 1024
#define HICN_MAX_RTX_MAX_AGE 10000
#define HICN_MIN_RTT_WIN 30 // rounds
#define HICN_MIN_INTER_ARRIVAL_GAP 100 // ms
// cwin
#define HICN_INITIAL_CWIN 1 // packets
#define HICN_INITIAL_CWIN_MAX 100000 // packets
#define HICN_MIN_CWIN 10 // packets
#define HICN_WIN_INCREASE_FACTOR 1.5
#define HICN_WIN_DECREASE_FACTOR 0.9
// statistics constants
#define HICN_BANDWIDTH_SLACK_FACTOR 1.8
#define HICN_ESTIMATED_BW_ALPHA 0.7
#define HICN_ESTIMATED_PACKET_SIZE 0.7
#define HICN_ESTIMATED_LOSSES_ALPHA 0.8
#define HICN_INTEREST_LIFETIME_REDUCTION_FACTOR 0.8
// other constants
#define HICN_NANO_IN_A_SEC 1000000000
#define HICN_MICRO_IN_A_SEC 1000000
#define HICN_MILLI_IN_A_SEC 1000
namespace transport {
namespace protocol {
enum packetState { sent_, nacked_, received_, timeout1_, timeout2_, lost_ };
typedef enum packetState packetState_t;
struct sentInterest {
uint64_t transmissionTime;
uint32_t sequence; // sequence number of the interest sent
// to handle seq % buffer_size
packetState_t state; // see packet state
};
class RTCTransportProtocol : public TransportProtocol,
public DatagramReassembly {
public:
RTCTransportProtocol(implementation::ConsumerSocket *icnet_socket);
~RTCTransportProtocol();
int start() override;
void stop() override;
void resume() override;
bool verifyKeyPackets() override;
private:
// algo functions
void reset() override;
// CC functions
void updateDelayStats(const ContentObject &content_object);
void updateStats(uint32_t round_duration);
void updateCCState();
void computeMaxWindow(uint32_t productionRate, uint32_t BDPWin);
void updateWindow();
void decreaseWindow();
void increaseWindow();
void resetPreviousWindow();
// packet functions
void sendInterest(Name *interest_name, bool rtx);
void scheduleNextInterests() override;
void sentinelTimer();
void addRetransmissions(uint32_t val);
void addRetransmissions(uint32_t start, uint32_t stop);
uint64_t retransmit();
void checkRtx();
void probeRtt();
void newRound();
void onTimeout(Interest::Ptr &&interest) override;
bool onNack(const ContentObject &content_object, bool rtx);
void onContentObject(Interest::Ptr &&interest,
ContentObject::Ptr &&content_object) override;
void onPacketDropped(Interest::Ptr &&interest,
ContentObject::Ptr &&content_object) override {}
void onReassemblyFailed(std::uint32_t missing_segment) override {}
TRANSPORT_ALWAYS_INLINE virtual void reassemble(
ContentObject::Ptr &&content_object) override {
auto read_buffer = content_object->getPayload();
read_buffer->trimStart(HICN_TIMESTAMP_SIZE);
Reassembly::read_buffer_ = std::move(read_buffer);
Reassembly::notifyApplication();
}
// controller var
std::unique_ptr<asio::steady_timer> round_timer_;
unsigned currentState_;
// cwin var
uint32_t currentCWin_;
uint32_t maxCWin_;
// names/packets var
uint32_t actualSegment_;
uint32_t inflightInterestsCount_;
// map seq to rtx
std::map<uint32_t, uint8_t> interestRetransmissions_;
bool rtx_timer_used_;
std::unique_ptr<asio::steady_timer> rtx_timer_;
std::vector<sentInterest> inflightInterests_;
uint32_t lastSegNacked_; // indicates the segment id in the last received
// past Nack. we do not ask for retransmissions
// for samething that is older than this value.
uint32_t lastReceived_; // segment of the last content object received
// indicates the base of the window on the client
uint64_t lastReceivedTime_; // time at which we recevied the
// lastReceived_ packet
// sentinel
// if all packets in the window get lost we need something that
// wakes up our consumer socket. Interest timeouts set to 1 sec
// expire too late. This timers expire much sooner and if it
// detects that all the interest in the window may be lost
// it sends all of them again
std::unique_ptr<asio::steady_timer> sentinel_timer_;
uint64_t lastEvent_; // time at which we removed a pending
// interest from the window
std::unordered_map<uint32_t, uint8_t> packets_in_window_;
// rtt probes
// the RTC transport tends to overestimate the RTT
// du to the production time on the server side
// once per second we send an interest for wich we know
// we will get a nack. This nack will keep our estimation
// close to the reality
std::unique_ptr<asio::steady_timer> probe_timer_;
uint64_t time_sent_probe_;
uint32_t probe_seq_number_;
bool received_probe_;
uint32_t modMask_;
// stats
bool firstPckReceived_;
uint32_t receivedBytes_;
uint32_t sentInterest_;
uint32_t receivedData_;
int32_t packetLost_;
int32_t lossRecovered_;
uint32_t firstSequenceInRound_;
uint32_t highestReceived_;
double avgPacketSize_;
bool gotNack_;
uint32_t gotFutureNack_;
uint32_t rounds_;
uint32_t roundsWithoutNacks_;
// we keep track of up two paths (if only one path is in use
// the two values in the vector will be the same)
// position 0 stores the path with minRTT
// position 1 stores the path with maxRTT
uint32_t producerPathLabels_[2];
std::unordered_map<uint32_t, std::shared_ptr<RTCDataPath>> pathTable_;
uint32_t roundCounter_;
// CC var
double estimatedBw_;
double lossRate_;
double queuingDelay_;
unsigned protocolState_;
bool initied;
};
} // namespace protocol
} // namespace transport
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