Move OctreePersistThread off GenericThread and add octree negotiation

assignment-client/src/octree/OctreeServer.cpp

@@ -231,18 +231,19 @@ void OctreeServer::trackProcessWaitTime(float time) {
 OctreeServer::OctreeServer(ReceivedMessage& message) :
     ThreadedAssignment(message),
     _argc(0),
-    _argv(NULL),
+    _argv(nullptr),
-    _parsedArgV(NULL),
+    _parsedArgV(nullptr),
+    _httpManager(nullptr),
     _statusPort(0),
     _packetsPerClientPerInterval(10),
     _packetsTotalPerInterval(DEFAULT_PACKETS_PER_INTERVAL),
-    _tree(NULL),
+    _tree(nullptr),
     _wantPersist(true),
     _debugSending(false),
     _debugReceiving(false),
     _verboseDebug(false),
-    _octreeInboundPacketProcessor(NULL),
+    _octreeInboundPacketProcessor(nullptr),
-    _persistThread(NULL),
+    _persistManager(nullptr),
     _started(time(0)),
     _startedUSecs(usecTimestampNow())
 {
@@ -265,11 +266,8 @@ OctreeServer::~OctreeServer() {
         _octreeInboundPacketProcessor->deleteLater();
     }
 
-    if (_persistThread) {
+    qDebug() << "Waiting for persist thread to come down";
-        _persistThread->terminating();
+    _persistThread.wait();
-        _persistThread->terminate();
-        _persistThread->deleteLater();
-    }
 
     // cleanup our tree here...
     qDebug() << qPrintable(_safeServerName) << "server START cleaning up octree... [" << this << "]";
@@ -1117,111 +1115,14 @@ void OctreeServer::run() {
 }
 
 void OctreeServer::domainSettingsRequestComplete() {
-    if (_state != OctreeServerState::WaitingForDomainSettings) {
-        qCWarning(octree_server) << "Received domain settings after they have already been received";
-        return;
-    }
-
     auto& packetReceiver = DependencyManager::get<NodeList>()->getPacketReceiver();
-    packetReceiver.registerListener(getMyQueryMessageType(), this, "handleOctreeQueryPacket");
     packetReceiver.registerListener(PacketType::OctreeDataNack, this, "handleOctreeDataNackPacket");
-
+    packetReceiver.registerListener(getMyQueryMessageType(), this, "handleOctreeQueryPacket");
-    packetReceiver.registerListener(PacketType::OctreeDataFileReply, this, "handleOctreeDataFileReply");
 
     qDebug(octree_server) << "Received domain settings";
 
     readConfiguration();
 
-    _state = OctreeServerState::WaitingForOctreeDataNegotation;
-
-    auto nodeList = DependencyManager::get<NodeList>();
-    const DomainHandler& domainHandler = nodeList->getDomainHandler();
-
-    auto packet = NLPacket::create(PacketType::OctreeDataFileRequest, -1, true, false);
-
-    OctreeUtils::RawOctreeData data;
-    qCDebug(octree_server) << "Reading octree data from" << _persistAbsoluteFilePath;
-    if (data.readOctreeDataInfoFromFile(_persistAbsoluteFilePath)) {
-        qCDebug(octree_server) << "Current octree data: ID(" << data.id << ") DataVersion(" << data.version << ")";
-        packet->writePrimitive(true);
-        auto id = data.id.toRfc4122();
-        packet->write(id);
-        packet->writePrimitive(data.version);
-    } else {
-        qCWarning(octree_server) << "No octree data found";
-        packet->writePrimitive(false);
-    }
-
-    qCDebug(octree_server) << "Sending request for octree data to DS";
-    nodeList->sendPacket(std::move(packet), domainHandler.getSockAddr());
-} 
-
-void OctreeServer::handleOctreeDataFileReply(QSharedPointer<ReceivedMessage> message) {
-    if (_state != OctreeServerState::WaitingForOctreeDataNegotation) {
-        qCWarning(octree_server) << "Server received ocree data file reply but is not currently negotiating.";
-        return;
-    }
-
-    bool includesNewData;
-    message->readPrimitive(&includesNewData);
-    QByteArray replaceData;
-    if (includesNewData) {
-        replaceData = message->readAll();
-        qDebug() << "Got reply to octree data file request, new data sent";
-    } else {
-        qDebug() << "Got reply to octree data file request, current entity data is sufficient";
-        
-        OctreeUtils::RawEntityData data;
-        qCDebug(octree_server) << "Reading octree data from" << _persistAbsoluteFilePath;
-        if (data.readOctreeDataInfoFromFile(_persistAbsoluteFilePath)) {
-            if (data.id.isNull()) {
-                qCDebug(octree_server) << "Current octree data has a null id, updating";
-                data.resetIdAndVersion();
-
-                QFile file(_persistAbsoluteFilePath);
-                if (file.open(QIODevice::WriteOnly)) {
-                    auto entityData = data.toGzippedByteArray();
-                    file.write(entityData);
-                    file.close();
-                } else {
-                    qCDebug(octree_server) << "Failed to update octree data";
-                }
-            }
-        }
-    }
-
-    _state = OctreeServerState::Running;
-    beginRunning(replaceData);
-}
-
-void OctreeServer::beginRunning(QByteArray replaceData) {
-    if (_state != OctreeServerState::Running) {
-        qCWarning(octree_server) << "Server is not running";
-        return;
-    }
-
-    auto nodeList = DependencyManager::get<NodeList>();
-
-    // we need to ask the DS about agents so we can ping/reply with them
-    nodeList->addSetOfNodeTypesToNodeInterestSet({ NodeType::Agent, NodeType::EntityScriptServer });
-
-    beforeRun(); // after payload has been processed
-
-    connect(nodeList.data(), SIGNAL(nodeAdded(SharedNodePointer)), SLOT(nodeAdded(SharedNodePointer)));
-    connect(nodeList.data(), SIGNAL(nodeKilled(SharedNodePointer)), SLOT(nodeKilled(SharedNodePointer)));
-
-#ifndef WIN32
-    setvbuf(stdout, NULL, _IOLBF, 0);
-#endif
-
-    nodeList->linkedDataCreateCallback = [this](Node* node) {
-        auto queryNodeData = createOctreeQueryNode();
-        queryNodeData->init();
-        node->setLinkedData(std::move(queryNodeData));
-    };
-
-    srand((unsigned)time(0));
-
     // if we want Persistence, set up the local file and persist thread
     if (_wantPersist) {
         static const QString ENTITY_PERSIST_EXTENSION = ".json.gz";
@@ -1279,10 +1180,42 @@ void OctreeServer::beginRunning(QByteArray replaceData) {
         auto persistFileDirectory = QFileInfo(_persistAbsoluteFilePath).absolutePath();
 
         // now set up PersistThread
-        _persistThread = new OctreePersistThread(_tree, _persistAbsoluteFilePath, _persistInterval, _debugTimestampNow,
+        _persistManager = new OctreePersistThread(_tree, _persistAbsoluteFilePath, _persistInterval, _debugTimestampNow,
-                                                 _persistAsFileType, replaceData);
+                                                 _persistAsFileType);
-        _persistThread->initialize(true);
+        _persistManager->moveToThread(&_persistThread);
+        connect(&_persistThread, &QThread::finished, _persistManager, &QObject::deleteLater);
+        connect(&_persistThread, &QThread::started, _persistManager, &OctreePersistThread::start);
+        connect(_persistManager, &OctreePersistThread::loadCompleted, this, [this]() {
+            beginRunning();
+        });
+        _persistThread.start();
+    } else {
+        beginRunning();
     }
+} 
+
+void OctreeServer::beginRunning() {
+    auto nodeList = DependencyManager::get<NodeList>();
+
+    // we need to ask the DS about agents so we can ping/reply with them
+    nodeList->addSetOfNodeTypesToNodeInterestSet({ NodeType::Agent, NodeType::EntityScriptServer });
+
+    beforeRun(); // after payload has been processed
+
+    connect(nodeList.data(), SIGNAL(nodeAdded(SharedNodePointer)), SLOT(nodeAdded(SharedNodePointer)));
+    connect(nodeList.data(), SIGNAL(nodeKilled(SharedNodePointer)), SLOT(nodeKilled(SharedNodePointer)));
+
+#ifndef WIN32
+    setvbuf(stdout, nullptr, _IOLBF, 0);
+#endif
+
+    nodeList->linkedDataCreateCallback = [this](Node* node) {
+        auto queryNodeData = createOctreeQueryNode();
+        queryNodeData->init();
+        node->setLinkedData(std::move(queryNodeData));
+    };
+
+    srand((unsigned)time(0));
 
     // set up our OctreeServerPacketProcessor
     _octreeInboundPacketProcessor = new OctreeInboundPacketProcessor(this);
@@ -1345,7 +1278,7 @@ void OctreeServer::aboutToFinish() {
 
     qDebug() << qPrintable(_safeServerName) << "inform Octree Inbound Packet Processor that we are shutting down...";
 
-    // we're going down - set the NodeList linkedDataCallback to NULL so we do not create any more OctreeQueryNode objects.
+    // we're going down - set the NodeList linkedDataCallback to nullptr so we do not create any more OctreeQueryNode objects.
     // This ensures that we don't get any more newly connecting nodes
     DependencyManager::get<NodeList>()->linkedDataCreateCallback = nullptr;
 
@@ -1363,9 +1296,8 @@ void OctreeServer::aboutToFinish() {
     // which waits on the thread to be done before returning
     _sendThreads.clear(); // Cleans up all the send threads.
 
-    if (_persistThread) {
+    if (_persistManager) {
-        _persistThread->aboutToFinish();
+        _persistThread.quit();
-        _persistThread->terminating();
     }
 
     qDebug() << qPrintable(_safeServerName) << "server ENDING about to finish...";

assignment-client/src/octree/OctreeServer.h

@@ -33,12 +33,6 @@ Q_DECLARE_LOGGING_CATEGORY(octree_server)
 
 const int DEFAULT_PACKETS_PER_INTERVAL = 2000; // some 120,000 packets per second total
 
-enum class OctreeServerState {
-    WaitingForDomainSettings,
-    WaitingForOctreeDataNegotation,
-    Running
-};
-
 /// Handles assignments of type OctreeServer - sending octrees to various clients.
 class OctreeServer : public ThreadedAssignment, public HTTPRequestHandler {
     Q_OBJECT
@@ -46,8 +40,6 @@ public:
     OctreeServer(ReceivedMessage& message);
     ~OctreeServer();
 
-    OctreeServerState _state { OctreeServerState::WaitingForDomainSettings };
-
     /// allows setting of run arguments
     void setArguments(int argc, char** argv);
 
@@ -68,12 +60,12 @@ public:
     static void clientConnected() { _clientCount++; }
     static void clientDisconnected() { _clientCount--; }
 
-    bool isInitialLoadComplete() const { return (_persistThread) ? _persistThread->isInitialLoadComplete() : true; }
+    bool isInitialLoadComplete() const { return (_persistManager) ? _persistManager->isInitialLoadComplete() : true; }
-    bool isPersistEnabled() const { return (_persistThread) ? true : false; }
+    bool isPersistEnabled() const { return (_persistManager) ? true : false; }
-    quint64 getLoadElapsedTime() const { return (_persistThread) ? _persistThread->getLoadElapsedTime() : 0; }
+    quint64 getLoadElapsedTime() const { return (_persistManager) ? _persistManager->getLoadElapsedTime() : 0; }
-    QString getPersistFilename() const { return (_persistThread) ? _persistThread->getPersistFilename() : ""; }
+    QString getPersistFilename() const { return (_persistManager) ? _persistManager->getPersistFilename() : ""; }
-    QString getPersistFileMimeType() const { return (_persistThread) ? _persistThread->getPersistFileMimeType() : "text/plain"; }
+    QString getPersistFileMimeType() const { return (_persistManager) ? _persistManager->getPersistFileMimeType() : "text/plain"; }
-    QByteArray getPersistFileContents() const { return (_persistThread) ? _persistThread->getPersistFileContents() : QByteArray(); }
+    QByteArray getPersistFileContents() const { return (_persistManager) ? _persistManager->getPersistFileContents() : QByteArray(); }
 
     // Subclasses must implement these methods
     virtual std::unique_ptr<OctreeQueryNode> createOctreeQueryNode() = 0;
@@ -149,7 +141,6 @@ private slots:
     void domainSettingsRequestComplete();
     void handleOctreeQueryPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer senderNode);
     void handleOctreeDataNackPacket(QSharedPointer<ReceivedMessage> message, SharedNodePointer senderNode);
-    void handleOctreeDataFileReply(QSharedPointer<ReceivedMessage> message);
     void removeSendThread();
 
 protected:
@@ -171,7 +162,7 @@ protected:
     QString getConfiguration();
     QString getStatusLink();
 
-    void beginRunning(QByteArray replaceData);
+    void beginRunning();
     
     UniqueSendThread createSendThread(const SharedNodePointer& node);
     virtual UniqueSendThread newSendThread(const SharedNodePointer& node) = 0;
@@ -199,7 +190,8 @@ protected:
     bool _debugTimestampNow;
     bool _verboseDebug;
     OctreeInboundPacketProcessor* _octreeInboundPacketProcessor;
-    OctreePersistThread* _persistThread;
+    OctreePersistThread* _persistManager;
+    QThread _persistThread;
 
     int _persistInterval;
     bool _persistFileDownload;

libraries/octree/src/OctreePersistThread.cpp

@@ -38,12 +38,11 @@
 const int OctreePersistThread::DEFAULT_PERSIST_INTERVAL = 1000 * 30; // every 30 seconds
 
 OctreePersistThread::OctreePersistThread(OctreePointer tree, const QString& filename, int persistInterval,
-                                         bool debugTimestampNow, QString persistAsFileType, const QByteArray& replacementData) :
+                                         bool debugTimestampNow, QString persistAsFileType) :
     _tree(tree),
     _filename(filename),
     _persistInterval(persistInterval),
     _initialLoadComplete(false),
-    _replacementData(replacementData),
     _loadTimeUSecs(0),
     _lastCheck(0),
     _debugTimestampNow(debugTimestampNow),
@@ -55,6 +54,140 @@ OctreePersistThread::OctreePersistThread(OctreePointer tree, const QString& file
     _filename = sansExt + "." + _persistAsFileType;
 }
 
+void OctreePersistThread::start() {
+    cleanupOldReplacementBackups();
+
+    QFile tempFile { getTempFilename() };
+    if (tempFile.exists()) {
+        qWarning(octree) << "Found temporary octree file at" << tempFile.fileName();
+        qDebug(octree) << "Attempting to recover from temporary octree file";
+        QFile::remove(_filename);
+        if (tempFile.rename(_filename)) {
+            qDebug(octree) << "Successfully recovered from temporary octree file";
+        } else {
+            qWarning(octree) << "Failed to recover from temporary octree file";
+            tempFile.remove();
+        }
+    }
+
+    auto& packetReceiver = DependencyManager::get<NodeList>()->getPacketReceiver();
+    packetReceiver.registerListener(PacketType::OctreeDataFileReply, this, "handleOctreeDataFileReply");
+
+    auto nodeList = DependencyManager::get<NodeList>();
+    const DomainHandler& domainHandler = nodeList->getDomainHandler();
+
+    auto packet = NLPacket::create(PacketType::OctreeDataFileRequest, -1, true, false);
+
+    OctreeUtils::RawOctreeData data;
+    qCDebug(octree) << "Reading octree data from" << _filename;
+    if (data.readOctreeDataInfoFromFile(_filename)) {
+        qCDebug(octree) << "Current octree data: ID(" << data.id << ") DataVersion(" << data.version << ")";
+        packet->writePrimitive(true);
+        auto id = data.id.toRfc4122();
+        packet->write(id);
+        packet->writePrimitive(data.version);
+    } else {
+        qCWarning(octree) << "No octree data found";
+        packet->writePrimitive(false);
+    }
+
+    qCDebug(octree) << "Sending request for octree data to DS";
+    nodeList->sendPacket(std::move(packet), domainHandler.getSockAddr());
+}
+
+void OctreePersistThread::handleOctreeDataFileReply(QSharedPointer<ReceivedMessage> message) {
+    if (_initialLoadComplete) {
+        qCWarning(octree) << "Received OctreeDataFileReply after initial load had completed";
+        return;
+    }
+
+    bool includesNewData;
+    message->readPrimitive(&includesNewData);
+    QByteArray replacementData;
+    if (includesNewData) {
+        replacementData = message->readAll();
+        replaceData(replacementData);
+        qDebug() << "Got reply to octree data file request, new data sent";
+    } else {
+        qDebug() << "Got reply to octree data file request, current entity data is sufficient";
+        
+        OctreeUtils::RawEntityData data;
+        qCDebug(octree) << "Reading octree data from" << _filename;
+        if (data.readOctreeDataInfoFromFile(_filename)) {
+            if (data.id.isNull()) {
+                qCDebug(octree) << "Current octree data has a null id, updating";
+                data.resetIdAndVersion();
+
+                QFile file(_filename);
+                if (file.open(QIODevice::WriteOnly)) {
+                    auto entityData = data.toGzippedByteArray();
+                    file.write(entityData);
+                    file.close();
+                } else {
+                    qCDebug(octree) << "Failed to update octree data";
+                }
+            }
+        }
+    }
+
+    quint64 loadStarted = usecTimestampNow();
+    qCDebug(octree) << "loading Octrees from file: " << _filename << "...";
+
+    OctreeUtils::RawOctreeData data;
+    if (data.readOctreeDataInfoFromFile(_filename)) {
+        qDebug() << "Setting entity version info to: " << data.id << data.version;
+        _tree->setOctreeVersionInfo(data.id, data.version);
+    }
+
+    bool persistentFileRead;
+
+    _tree->withWriteLock([&] {
+        PerformanceWarning warn(true, "Loading Octree File", true);
+
+        persistentFileRead = _tree->readFromFile(_filename.toLocal8Bit().constData());
+        _tree->pruneTree();
+    });
+
+    quint64 loadDone = usecTimestampNow();
+    _loadTimeUSecs = loadDone - loadStarted;
+
+    _tree->clearDirtyBit(); // the tree is clean since we just loaded it
+    qCDebug(octree, "DONE loading Octrees from file... fileRead=%s", debug::valueOf(persistentFileRead));
+
+    unsigned long nodeCount = OctreeElement::getNodeCount();
+    unsigned long internalNodeCount = OctreeElement::getInternalNodeCount();
+    unsigned long leafNodeCount = OctreeElement::getLeafNodeCount();
+    qCDebug(octree, "Nodes after loading scene %lu nodes %lu internal %lu leaves", nodeCount, internalNodeCount, leafNodeCount);
+
+    bool wantDebug = false;
+    if (wantDebug) {
+        double usecPerGet = (double)OctreeElement::getGetChildAtIndexTime() 
+                                / (double)OctreeElement::getGetChildAtIndexCalls();
+        qCDebug(octree) << "getChildAtIndexCalls=" << OctreeElement::getGetChildAtIndexCalls()
+                << " getChildAtIndexTime=" << OctreeElement::getGetChildAtIndexTime() << " perGet=" << usecPerGet;
+
+        double usecPerSet = (double)OctreeElement::getSetChildAtIndexTime() 
+                                / (double)OctreeElement::getSetChildAtIndexCalls();
+        qCDebug(octree) << "setChildAtIndexCalls=" << OctreeElement::getSetChildAtIndexCalls()
+                << " setChildAtIndexTime=" << OctreeElement::getSetChildAtIndexTime() << " perSet=" << usecPerSet;
+    }
+
+    _initialLoadComplete = true;
+
+    // Since we just loaded the persistent file, we can consider ourselves as having "just checked" for persistance.
+    _lastCheck = usecTimestampNow(); // we just loaded, no need to save again
+
+    if (replacementData.isNull()) {
+        sendLatestEntityDataToDS();
+    }
+
+    qDebug() << "Starting timer";
+    QTimer::singleShot(_persistInterval, this, &OctreePersistThread::process);
+
+    emit loadCompleted();
+}
+
+
 QString OctreePersistThread::getPersistFileMimeType() const {
     if (_persistAsFileType == "json") {
         return "application/json";
@@ -96,68 +229,9 @@ bool OctreePersistThread::backupCurrentFile() {
 }
 
 bool OctreePersistThread::process() {
+    qDebug() << "Processing...";
 
-    if (!_initialLoadComplete) {
+    if (true) { //isStillRunning()) {
-        quint64 loadStarted = usecTimestampNow();
-        qCDebug(octree) << "loading Octrees from file: " << _filename << "...";
-
-        if (!_replacementData.isNull()) {
-            replaceData(_replacementData);
-        }
-
-        OctreeUtils::RawOctreeData data;
-        if (data.readOctreeDataInfoFromFile(_filename)) {
-            qDebug() << "Setting entity version info to: " << data.id << data.dataVersion;
-            _tree->setOctreeVersionInfo(data.id, data.dataVersion);
-        }
-
-        bool persistentFileRead;
-
-        _tree->withWriteLock([&] {
-            PerformanceWarning warn(true, "Loading Octree File", true);
-
-            persistentFileRead = _tree->readFromFile(_filename.toLocal8Bit().constData());
-            _tree->pruneTree();
-        });
-
-        quint64 loadDone = usecTimestampNow();
-        _loadTimeUSecs = loadDone - loadStarted;
-
-        _tree->clearDirtyBit(); // the tree is clean since we just loaded it
-        qCDebug(octree, "DONE loading Octrees from file... fileRead=%s", debug::valueOf(persistentFileRead));
-
-        unsigned long nodeCount = OctreeElement::getNodeCount();
-        unsigned long internalNodeCount = OctreeElement::getInternalNodeCount();
-        unsigned long leafNodeCount = OctreeElement::getLeafNodeCount();
-        qCDebug(octree, "Nodes after loading scene %lu nodes %lu internal %lu leaves", nodeCount, internalNodeCount, leafNodeCount);
-
-        bool wantDebug = false;
-        if (wantDebug) {
-            double usecPerGet = (double)OctreeElement::getGetChildAtIndexTime() 
-                                    / (double)OctreeElement::getGetChildAtIndexCalls();
-            qCDebug(octree) << "getChildAtIndexCalls=" << OctreeElement::getGetChildAtIndexCalls()
-                    << " getChildAtIndexTime=" << OctreeElement::getGetChildAtIndexTime() << " perGet=" << usecPerGet;
-
-            double usecPerSet = (double)OctreeElement::getSetChildAtIndexTime() 
-                                    / (double)OctreeElement::getSetChildAtIndexCalls();
-            qCDebug(octree) << "setChildAtIndexCalls=" << OctreeElement::getSetChildAtIndexCalls()
-                    << " setChildAtIndexTime=" << OctreeElement::getSetChildAtIndexTime() << " perSet=" << usecPerSet;
-        }
-
-        _initialLoadComplete = true;
-
-        // Since we just loaded the persistent file, we can consider ourselves as having "just checked" for persistance.
-        _lastCheck = usecTimestampNow(); // we just loaded, no need to save again
-
-        if (_replacementData.isNull()) {
-            sendLatestEntityDataToDS();
-        }
-        _replacementData.clear();
-
-        emit loadCompleted();
-    }
-
-    if (isStillRunning()) {
         quint64 MSECS_TO_USECS = 1000;
         quint64 USECS_TO_SLEEP = 10 * MSECS_TO_USECS; // every 10ms
         std::this_thread::sleep_for(std::chrono::microseconds(USECS_TO_SLEEP));
@@ -186,14 +260,15 @@ bool OctreePersistThread::process() {
         }
         
     }
-    return isStillRunning();  // keep running till they terminate us
+    //return isStillRunning();  // keep running till they terminate us
+    QTimer::singleShot(1000, this, &OctreePersistThread::process);
+    return true;
 }
 
 void OctreePersistThread::aboutToFinish() {
     qCDebug(octree) << "Persist thread about to finish...";
     persist();
     qCDebug(octree) << "Persist thread done with about to finish...";
-    _stopThread = true;
 }
 
 QByteArray OctreePersistThread::getPersistFileContents() const {

libraries/octree/src/OctreePersistThread.h

@@ -18,7 +18,7 @@
 #include <GenericThread.h>
 #include "Octree.h"
 
-class OctreePersistThread : public GenericThread {
+class OctreePersistThread : public QObject {
     Q_OBJECT
 public:
     class BackupRule {
@@ -36,8 +36,7 @@ public:
                         const QString& filename,
                         int persistInterval = DEFAULT_PERSIST_INTERVAL,
                         bool debugTimestampNow = false,
-                        QString persistAsFileType = "json.gz",
+                        QString persistAsFileType = "json.gz");
-                        const QByteArray& replacementData = QByteArray());
 
     bool isInitialLoadComplete() const { return _initialLoadComplete; }
     quint64 getLoadElapsedTime() const { return _loadTimeUSecs; }
@@ -48,25 +47,31 @@ public:
 
     void aboutToFinish(); /// call this to inform the persist thread that the owner is about to finish to support final persist
 
+public slots:
+    void start();
+
 signals:
     void loadCompleted();
 
-protected:
+protected slots:
-    /// Implements generic processing behavior for this thread.
+    bool process();
-    virtual bool process() override;
+    void handleOctreeDataFileReply(QSharedPointer<ReceivedMessage> message);
 
+protected:
     void persist();
     bool backupCurrentFile();
+    void cleanupOldReplacementBackups();
 
     void replaceData(QByteArray data);
     void sendLatestEntityDataToDS();
 
+    QString getTempFilename() const { return _filename + ".temp"; }
+
 private:
     OctreePointer _tree;
     QString _filename;
     int _persistInterval;
     bool _initialLoadComplete;
-    QByteArray _replacementData;
 
     quint64 _loadTimeUSecs;