SentPacketHistory now handles rollover

updated SentPacketHistory path in comments
This commit is contained in:
wangyix 2014-06-16 15:59:38 -07:00
parent ddfe98ad43
commit 5e37704772
3 changed files with 20 additions and 12 deletions

View file

@ -1,6 +1,6 @@
// //
// SentPacketHistory.cpp // SentPacketHistory.cpp
// assignement-client/src/octree // libraries/networking/src
// //
// Created by Yixin Wang on 6/5/2014 // Created by Yixin Wang on 6/5/2014
// //
@ -18,7 +18,7 @@ SentPacketHistory::SentPacketHistory(int size)
{ {
} }
void SentPacketHistory::packetSent(OCTREE_PACKET_SEQUENCE sequenceNumber, const QByteArray& packet) { void SentPacketHistory::packetSent(uint16_t sequenceNumber, const QByteArray& packet) {
_newestSequenceNumber = sequenceNumber; _newestSequenceNumber = sequenceNumber;
// increment _newestPacketAt cyclically, insert new packet there. // increment _newestPacketAt cyclically, insert new packet there.
@ -31,9 +31,18 @@ void SentPacketHistory::packetSent(OCTREE_PACKET_SEQUENCE sequenceNumber, const
} }
const QByteArray* SentPacketHistory::getPacket(OCTREE_PACKET_SEQUENCE sequenceNumber) const { const QByteArray* SentPacketHistory::getPacket(uint16_t sequenceNumber) const {
OCTREE_PACKET_SEQUENCE seqDiff = _newestSequenceNumber - sequenceNumber;
if (!(seqDiff >= 0 && seqDiff < _numExistingPackets)) { const int UINT16_RANGE = UINT16_MAX + 1;
// if sequenceNumber > _newestSequenceNumber, assume sequenceNumber is from before the most recent rollover
// correct the diff so that it correctly represents how far back in the history sequenceNumber is
int seqDiff = (int)_newestSequenceNumber - (int)sequenceNumber;
if (seqDiff < 0) {
seqDiff += UINT16_RANGE;
}
// if desired sequence number is too old to be found in the history, return null
if (seqDiff >= _numExistingPackets) {
return NULL; return NULL;
} }
int packetAt = _newestPacketAt - seqDiff; int packetAt = _newestPacketAt - seqDiff;

View file

@ -1,6 +1,6 @@
// //
// SentPacketHistory.h // SentPacketHistory.h
// assignement-client/src/octree // libraries/networking/src
// //
// Created by Yixin Wang on 6/5/2014 // Created by Yixin Wang on 6/5/2014
// //
@ -11,25 +11,24 @@
#ifndef hifi_SentPacketHistory_h #ifndef hifi_SentPacketHistory_h
#define hifi_SentPacketHistory_h #define hifi_SentPacketHistory_h
#include <stdint.h>
#include <qbytearray.h> #include <qbytearray.h>
#include <qvector.h> #include <qvector.h>
#include "OctreePacketData.h"
class SentPacketHistory { class SentPacketHistory {
public: public:
SentPacketHistory(int size); SentPacketHistory(int size);
void packetSent(OCTREE_PACKET_SEQUENCE sequenceNumber, const QByteArray& packet); void packetSent(uint16_t sequenceNumber, const QByteArray& packet);
const QByteArray* getPacket(OCTREE_PACKET_SEQUENCE sequenceNumber) const; const QByteArray* getPacket(uint16_t sequenceNumber) const;
private: private:
QVector<QByteArray> _sentPackets; // circular buffer QVector<QByteArray> _sentPackets; // circular buffer
int _newestPacketAt; int _newestPacketAt;
int _numExistingPackets; int _numExistingPackets;
OCTREE_PACKET_SEQUENCE _newestSequenceNumber; uint16_t _newestSequenceNumber;
}; };
#endif #endif

View file

@ -133,7 +133,7 @@ protected:
unsigned short int _sequenceNumber; unsigned short int _sequenceNumber;
int _maxPacketSize; int _maxPacketSize;
// TODO: garbage-collect this // TODO: garbage-collect this and _pendingEditPackets
QHash<QUuid, NackedPacketHistory> _nackedPacketHistories; QHash<QUuid, NackedPacketHistory> _nackedPacketHistories;
}; };
#endif // hifi_OctreeEditPacketSender_h #endif // hifi_OctreeEditPacketSender_h