From ddfe98ad43a1e4a545807f5faeac65a4d1d6fd0b Mon Sep 17 00:00:00 2001
From: wangyix <wangyix@gmail.com>
Date: Mon, 16 Jun 2014 15:32:39 -0700
Subject: [PATCH] added code to parse nack packets in OctreeEditPacketSender

---
 .../octree/src/OctreeEditPacketSender.cpp     | 49 +++++++++++++++++--
 libraries/octree/src/OctreeEditPacketSender.h | 21 ++++++++
 2 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/libraries/octree/src/OctreeEditPacketSender.cpp b/libraries/octree/src/OctreeEditPacketSender.cpp
index fb0059b96d..69b58aaa41 100644
--- a/libraries/octree/src/OctreeEditPacketSender.cpp
+++ b/libraries/octree/src/OctreeEditPacketSender.cpp
@@ -17,6 +17,43 @@
 #include <PacketHeaders.h>
 #include "OctreeEditPacketSender.h"
 
+void NackedPacketHistory::packetSent(const QByteArray& packet) {
+    // extract sequence number for the sent packet history
+    int numBytesPacketHeader = numBytesForPacketHeader(packet);
+    const char* dataAt = reinterpret_cast<const char*>(packet.data());
+    unsigned short int sequence = (*((unsigned short int*)(dataAt + numBytesPacketHeader)));
+
+    // add packet to history
+    _sentPacketHistory.packetSent(sequence, packet);
+}
+
+bool NackedPacketHistory::hasNextNackedPacket() const {
+    return !_nackedSequenceNumbers.isEmpty();
+}
+
+const QByteArray* NackedPacketHistory::getNextNackedPacket() {
+    if (!_nackedSequenceNumbers.isEmpty()) {
+        // could return null if packet is not in the history
+        return _sentPacketHistory.getPacket(_nackedSequenceNumbers.dequeue());
+    }
+    return NULL;
+}
+
+void NackedPacketHistory::parseNackPacket(const QByteArray& packet) {
+    int numBytesPacketHeader = numBytesForPacketHeader(packet);
+    const unsigned char* dataAt = reinterpret_cast<const unsigned char*>(packet.data()) + numBytesPacketHeader;
+
+    // read number of sequence numbers
+    uint16_t numSequenceNumbers = (*(uint16_t*)dataAt);
+    dataAt += sizeof(uint16_t);
+
+    // read sequence numbers
+    for (int i = 0; i < numSequenceNumbers; i++) {
+        unsigned short int sequenceNumber = (*(unsigned short int*)dataAt);
+        _nackedSequenceNumbers.enqueue(sequenceNumber);
+        dataAt += sizeof(unsigned short int);
+    }
+}
 
 EditPacketBuffer::EditPacketBuffer(PacketType type, unsigned char* buffer, ssize_t length, QUuid nodeUUID) :
     _nodeUUID(nodeUUID),
@@ -97,9 +134,9 @@ void OctreeEditPacketSender::queuePacketToNode(const QUuid& nodeUUID, unsigned c
         if (node->getType() == getMyNodeType() &&
             ((node->getUUID() == nodeUUID) || (nodeUUID.isNull()))) {
             if (node->getActiveSocket()) {
-                queuePacketForSending(node, QByteArray(reinterpret_cast<char*>(buffer), length));
-
-
+                QByteArray packet(reinterpret_cast<char*>(buffer), length);
+                queuePacketForSending(node, packet);
+                _nackedPacketHistories[nodeUUID].packetSent(packet);
 
                 // debugging output...
                 bool wantDebugging = false;
@@ -338,3 +375,9 @@ bool OctreeEditPacketSender::process() {
     // base class does most of the work.
     return PacketSender::process();
 }
+
+void OctreeEditPacketSender::parseNackPacket(const QByteArray& packet) {
+    // parse sending node from packet
+    QUuid sendingNodeUUID = uuidFromPacketHeader(packet);
+    _nackedPacketHistories[sendingNodeUUID].parseNackPacket(packet);
+}
diff --git a/libraries/octree/src/OctreeEditPacketSender.h b/libraries/octree/src/OctreeEditPacketSender.h
index 167e43b200..2586ca034f 100644
--- a/libraries/octree/src/OctreeEditPacketSender.h
+++ b/libraries/octree/src/OctreeEditPacketSender.h
@@ -12,9 +12,24 @@
 #ifndef hifi_OctreeEditPacketSender_h
 #define hifi_OctreeEditPacketSender_h
 
+#include <qqueue.h>
 #include <PacketSender.h>
 #include <PacketHeaders.h>
 #include "JurisdictionMap.h"
+#include "SentPacketHistory.h"
+
+class NackedPacketHistory {
+public:
+    NackedPacketHistory() : _sentPacketHistory(1000), _nackedSequenceNumbers()  { }
+public:
+    void packetSent(const QByteArray& packet);
+    bool hasNextNackedPacket() const;
+    const QByteArray* getNextNackedPacket();
+    void parseNackPacket(const QByteArray& packet);
+private:
+    SentPacketHistory _sentPacketHistory;
+    QQueue<unsigned short int> _nackedSequenceNumbers;
+};
 
 /// Used for construction of edit packets
 class EditPacketBuffer {
@@ -90,6 +105,9 @@ public:
     virtual char getMyNodeType() const = 0;
     virtual void adjustEditPacketForClockSkew(unsigned char* codeColorBuffer, ssize_t length, int clockSkew) { };
     
+public:
+    void parseNackPacket(const QByteArray& packet);
+
 protected:
     bool _shouldSend;
     void queuePacketToNode(const QUuid& nodeID, unsigned char* buffer, ssize_t length);
@@ -114,5 +132,8 @@ protected:
     
     unsigned short int _sequenceNumber;
     int _maxPacketSize;
+
+    // TODO: garbage-collect this
+    QHash<QUuid, NackedPacketHistory> _nackedPacketHistories;
 };
 #endif // hifi_OctreeEditPacketSender_h