ZLMediaKit/srt/PacketQueue.cpp
2022-06-07 09:52:20 +08:00

230 lines
6.2 KiB
C++

#include "PacketQueue.hpp"
namespace SRT {
#define MAX_SEQ 0x7fffffff
#define MAX_TS 0xffffffff
static inline uint32_t genExpectedSeq(uint32_t seq) {
return MAX_SEQ & seq;
}
static inline bool isSeqEdge(uint32_t seq, uint32_t cap) {
if (seq > (MAX_SEQ - cap)) {
return true;
}
return false;
}
static inline bool isTSCycle(uint32_t first, uint32_t second) {
uint32_t diff;
if (first > second) {
diff = first - second;
} else {
diff = second - first;
}
if (diff > (MAX_TS >> 1)) {
return true;
} else {
return false;
}
}
PacketQueue::PacketQueue(uint32_t max_size, uint32_t init_seq, uint32_t latency)
: _pkt_cap(max_size)
, _pkt_latency(latency)
, _pkt_expected_seq(init_seq) {}
void PacketQueue::tryInsertPkt(DataPacket::Ptr pkt) {
if (_pkt_expected_seq <= pkt->packet_seq_number) {
auto diff = pkt->packet_seq_number - _pkt_expected_seq;
if (diff >= (MAX_SEQ >> 1)) {
TraceL << "drop packet too later for cycle "
<< "expected seq=" << _pkt_expected_seq << " pkt seq=" << pkt->packet_seq_number;
return;
} else {
_pkt_map.emplace(pkt->packet_seq_number, pkt);
}
} else {
auto diff = _pkt_expected_seq - pkt->packet_seq_number;
if (diff >= (MAX_SEQ >> 1)) {
_pkt_map.emplace(pkt->packet_seq_number, pkt);
TraceL << " cycle packet "
<< "expected seq=" << _pkt_expected_seq << " pkt seq=" << pkt->packet_seq_number;
} else {
// TraceL << "drop packet too later "<< "expected seq=" << _pkt_expected_seq << " pkt seq=" <<
// pkt->packet_seq_number;
}
}
}
bool PacketQueue::inputPacket(DataPacket::Ptr pkt, std::list<DataPacket::Ptr> &out) {
tryInsertPkt(pkt);
auto it = _pkt_map.find(_pkt_expected_seq);
while (it != _pkt_map.end()) {
out.push_back(it->second);
_pkt_map.erase(it);
_pkt_expected_seq = genExpectedSeq(_pkt_expected_seq + 1);
it = _pkt_map.find(_pkt_expected_seq);
}
while (_pkt_map.size() > _pkt_cap) {
// 防止回环
it = _pkt_map.find(_pkt_expected_seq);
if (it != _pkt_map.end()) {
out.push_back(it->second);
_pkt_map.erase(it);
}
_pkt_expected_seq = genExpectedSeq(_pkt_expected_seq + 1);
}
while (timeLatency() > _pkt_latency) {
it = _pkt_map.find(_pkt_expected_seq);
if (it != _pkt_map.end()) {
out.push_back(it->second);
_pkt_map.erase(it);
}
_pkt_expected_seq = genExpectedSeq(_pkt_expected_seq + 1);
}
return true;
}
bool PacketQueue::drop(uint32_t first, uint32_t last, std::list<DataPacket::Ptr> &out) {
uint32_t end = genExpectedSeq(last + 1);
decltype(_pkt_map.end()) it;
for (uint32_t i = _pkt_expected_seq; i < end;) {
it = _pkt_map.find(i);
if (it != _pkt_map.end()) {
out.push_back(it->second);
_pkt_map.erase(it);
}
i = genExpectedSeq(i + 1);
}
_pkt_expected_seq = end;
return true;
}
uint32_t PacketQueue::timeLatency() {
if (_pkt_map.empty()) {
return 0;
}
auto first = _pkt_map.begin()->second->timestamp;
auto last = _pkt_map.rbegin()->second->timestamp;
uint32_t dur;
if (last > first) {
dur = last - first;
} else {
dur = first - last;
}
if (dur > 0x80000000) {
dur = MAX_TS - dur;
WarnL << "cycle dur " << dur;
}
return dur;
}
std::list<PacketQueue::LostPair> PacketQueue::getLostSeq() {
std::list<PacketQueue::LostPair> re;
if (_pkt_map.empty()) {
return re;
}
if (getExpectedSize() == getSize()) {
return re;
}
uint32_t end = 0;
uint32_t first, last;
first = _pkt_map.begin()->second->packet_seq_number;
last = _pkt_map.rbegin()->second->packet_seq_number;
if ((last - first) > (MAX_SEQ >> 1)) {
TraceL << " cycle seq first " << first << " last " << last << " size " << _pkt_map.size();
end = first;
} else {
end = last;
}
PacketQueue::LostPair lost;
lost.first = 0;
lost.second = 0;
uint32_t i = _pkt_expected_seq;
bool finish = true;
for (i = _pkt_expected_seq; i <= end;) {
if (_pkt_map.find(i) == _pkt_map.end()) {
if (finish) {
finish = false;
lost.first = i;
lost.second = i + 1;
} else {
lost.second = i + 1;
}
} else {
if (!finish) {
finish = true;
re.push_back(lost);
}
}
i = genExpectedSeq(i + 1);
}
return re;
}
size_t PacketQueue::getSize() {
return _pkt_map.size();
}
size_t PacketQueue::getExpectedSize() {
if (_pkt_map.empty()) {
return 0;
}
uint32_t max = _pkt_map.rbegin()->first;
uint32_t min = _pkt_map.begin()->first;
if ((max - min) >= (MAX_SEQ >> 1)) {
TraceL << "cycle "
<< "expected seq " << _pkt_expected_seq << " min " << min << " max " << max << " size "
<< _pkt_map.size();
return MAX_SEQ - _pkt_expected_seq + min + 1;
} else {
return max - _pkt_expected_seq + 1;
}
}
size_t PacketQueue::getAvailableBufferSize() {
auto size = getExpectedSize();
if (_pkt_cap > size) {
return _pkt_cap - size;
}
if (_pkt_cap > _pkt_map.size()) {
return _pkt_cap - _pkt_map.size();
}
WarnL << " cap " << _pkt_cap << " expected size " << size << " map size " << _pkt_map.size();
return _pkt_cap;
}
uint32_t PacketQueue::getExpectedSeq() {
return _pkt_expected_seq;
}
std::string PacketQueue::dump() {
_StrPrinter printer;
if (_pkt_map.empty()) {
printer << " expected seq :" << _pkt_expected_seq;
} else {
printer << " expected seq :" << _pkt_expected_seq << " size:" << _pkt_map.size()
<< " first:" << _pkt_map.begin()->second->packet_seq_number;
printer << " last:" << _pkt_map.rbegin()->second->packet_seq_number;
printer << " latency:" << timeLatency() / 1e3;
}
return std::move(printer);
}
} // namespace SRT