chat: fix issues with quickly switching between multiple chats (#2343)

* prevent load progress from getting out of sync with the current chat
* fix memory leak on exit if the LLModelStore contains a model
* do not report cancellation as a failure in console/Mixpanel
* show "waiting for model" separately from "switching context" in UI
* do not show lower "reload" button on error
* skip context switch if unload is pending
* skip unnecessary calls to LLModel::saveState

Signed-off-by: Jared Van Bortel <jared@nomic.ai>

gpt4all-chat/chat.cpp

@@ -54,7 +54,7 @@ void Chat::connectLLM()
     connect(m_llmodel, &ChatLLM::reportFallbackReason, this, &Chat::handleFallbackReasonChanged, Qt::QueuedConnection);
     connect(m_llmodel, &ChatLLM::databaseResultsChanged, this, &Chat::handleDatabaseResultsChanged, Qt::QueuedConnection);
     connect(m_llmodel, &ChatLLM::modelInfoChanged, this, &Chat::handleModelInfoChanged, Qt::QueuedConnection);
-    connect(m_llmodel, &ChatLLM::trySwitchContextOfLoadedModelCompleted, this, &Chat::trySwitchContextOfLoadedModelCompleted, Qt::QueuedConnection);
+    connect(m_llmodel, &ChatLLM::trySwitchContextOfLoadedModelCompleted, this, &Chat::handleTrySwitchContextOfLoadedModelCompleted, Qt::QueuedConnection);
 
     connect(this, &Chat::promptRequested, m_llmodel, &ChatLLM::prompt, Qt::QueuedConnection);
     connect(this, &Chat::modelChangeRequested, m_llmodel, &ChatLLM::modelChangeRequested, Qt::QueuedConnection);
@@ -95,16 +95,6 @@ void Chat::processSystemPrompt()
     emit processSystemPromptRequested();
 }
 
-bool Chat::isModelLoaded() const
-{
-    return m_modelLoadingPercentage == 1.0f;
-}
-
-float Chat::modelLoadingPercentage() const
-{
-    return m_modelLoadingPercentage;
-}
-
 void Chat::resetResponseState()
 {
     if (m_responseInProgress && m_responseState == Chat::LocalDocsRetrieval)
@@ -167,9 +157,16 @@ void Chat::handleModelLoadingPercentageChanged(float loadingPercentage)
     if (loadingPercentage == m_modelLoadingPercentage)
         return;
 
+    bool wasLoading = isCurrentlyLoading();
+    bool wasLoaded = isModelLoaded();
+
     m_modelLoadingPercentage = loadingPercentage;
     emit modelLoadingPercentageChanged();
-    if (m_modelLoadingPercentage == 1.0f || m_modelLoadingPercentage == 0.0f)
+
+    if (isCurrentlyLoading() != wasLoading)
+        emit isCurrentlyLoadingChanged();
+
+    if (isModelLoaded() != wasLoaded)
         emit isModelLoadedChanged();
 }
 
@@ -247,10 +244,6 @@ void Chat::setModelInfo(const ModelInfo &modelInfo)
     if (m_modelInfo == modelInfo && isModelLoaded())
         return;
 
-    m_modelLoadingPercentage = std::numeric_limits<float>::min(); // small non-zero positive value
-    emit isModelLoadedChanged();
-    m_modelLoadingError = QString();
-    emit modelLoadingErrorChanged();
     m_modelInfo = modelInfo;
     emit modelInfoChanged();
     emit modelChangeRequested(modelInfo);
@@ -320,8 +313,9 @@ void Chat::forceReloadModel()
 
 void Chat::trySwitchContextOfLoadedModel()
 {
-    emit trySwitchContextOfLoadedModelAttempted();
-    m_llmodel->setShouldTrySwitchContext(true);
+    m_trySwitchContextInProgress = 1;
+    emit trySwitchContextInProgressChanged();
+    m_llmodel->requestTrySwitchContext();
 }
 
 void Chat::generatedNameChanged(const QString &name)
@@ -342,8 +336,10 @@ void Chat::handleRecalculating()
 
 void Chat::handleModelLoadingError(const QString &error)
 {
-    auto stream = qWarning().noquote() << "ERROR:" << error << "id";
-    stream.quote() << id();
+    if (!error.isEmpty()) {
+        auto stream = qWarning().noquote() << "ERROR:" << error << "id";
+        stream.quote() << id();
+    }
     m_modelLoadingError = error;
     emit modelLoadingErrorChanged();
 }
@@ -380,6 +376,11 @@ void Chat::handleModelInfoChanged(const ModelInfo &modelInfo)
     emit modelInfoChanged();
 }
 
+void Chat::handleTrySwitchContextOfLoadedModelCompleted(int value) {
+    m_trySwitchContextInProgress = value;
+    emit trySwitchContextInProgressChanged();
+}
+
 bool Chat::serialize(QDataStream &stream, int version) const
 {
     stream << m_creationDate;

gpt4all-chat/chat.h

@@ -17,6 +17,7 @@ class Chat : public QObject
     Q_PROPERTY(QString name READ name WRITE setName NOTIFY nameChanged)
     Q_PROPERTY(ChatModel *chatModel READ chatModel NOTIFY chatModelChanged)
     Q_PROPERTY(bool isModelLoaded READ isModelLoaded NOTIFY isModelLoadedChanged)
+    Q_PROPERTY(bool isCurrentlyLoading READ isCurrentlyLoading NOTIFY isCurrentlyLoadingChanged)
     Q_PROPERTY(float modelLoadingPercentage READ modelLoadingPercentage NOTIFY modelLoadingPercentageChanged)
     Q_PROPERTY(QString response READ response NOTIFY responseChanged)
     Q_PROPERTY(ModelInfo modelInfo READ modelInfo WRITE setModelInfo NOTIFY modelInfoChanged)
@@ -30,6 +31,8 @@ class Chat : public QObject
     Q_PROPERTY(QString device READ device NOTIFY deviceChanged);
     Q_PROPERTY(QString fallbackReason READ fallbackReason NOTIFY fallbackReasonChanged);
     Q_PROPERTY(LocalDocsCollectionsModel *collectionModel READ collectionModel NOTIFY collectionModelChanged)
+    // 0=no, 1=waiting, 2=working
+    Q_PROPERTY(int trySwitchContextInProgress READ trySwitchContextInProgress NOTIFY trySwitchContextInProgressChanged)
     QML_ELEMENT
     QML_UNCREATABLE("Only creatable from c++!")
 
@@ -62,8 +65,9 @@ class Chat : public QObject
 
     Q_INVOKABLE void reset();
     Q_INVOKABLE void processSystemPrompt();
-    Q_INVOKABLE bool isModelLoaded() const;
-    Q_INVOKABLE float modelLoadingPercentage() const;
+    bool  isModelLoaded()          const { return m_modelLoadingPercentage == 1.0f; }
+    bool  isCurrentlyLoading()     const { return m_modelLoadingPercentage > 0.0f && m_modelLoadingPercentage < 1.0f; }
+    float modelLoadingPercentage() const { return m_modelLoadingPercentage; }
     Q_INVOKABLE void prompt(const QString &prompt);
     Q_INVOKABLE void regenerateResponse();
     Q_INVOKABLE void stopGenerating();
@@ -105,6 +109,8 @@ class Chat : public QObject
     QString device() const { return m_device; }
     QString fallbackReason() const { return m_fallbackReason; }
 
+    int trySwitchContextInProgress() const { return m_trySwitchContextInProgress; }
+
 public Q_SLOTS:
     void serverNewPromptResponsePair(const QString &prompt);
 
@@ -113,6 +119,7 @@ public Q_SLOTS:
     void nameChanged();
     void chatModelChanged();
     void isModelLoadedChanged();
+    void isCurrentlyLoadingChanged();
     void modelLoadingPercentageChanged();
     void modelLoadingWarning(const QString &warning);
     void responseChanged();
@@ -136,8 +143,7 @@ public Q_SLOTS:
     void deviceChanged();
     void fallbackReasonChanged();
     void collectionModelChanged();
-    void trySwitchContextOfLoadedModelAttempted();
-    void trySwitchContextOfLoadedModelCompleted(bool);
+    void trySwitchContextInProgressChanged();
 
 private Q_SLOTS:
     void handleResponseChanged(const QString &response);
@@ -152,6 +158,7 @@ private Q_SLOTS:
     void handleFallbackReasonChanged(const QString &device);
     void handleDatabaseResultsChanged(const QList<ResultInfo> &results);
     void handleModelInfoChanged(const ModelInfo &modelInfo);
+    void handleTrySwitchContextOfLoadedModelCompleted(int value);
 
 private:
     QString m_id;
@@ -176,6 +183,8 @@ private Q_SLOTS:
     float m_modelLoadingPercentage = 0.0f;
     LocalDocsCollectionsModel *m_collectionModel;
     bool m_firstResponse = true;
+    int m_trySwitchContextInProgress = 0;
+    bool m_isCurrentlyLoading = false;
 };
 
 #endif // CHAT_H

gpt4all-chat/chatlistmodel.h

@@ -195,7 +195,11 @@ class ChatListModel : public QAbstractListModel
     int count() const { return m_chats.size(); }
 
     // stop ChatLLM threads for clean shutdown
-    void destroyChats() { for (auto *chat: m_chats) { chat->destroy(); } }
+    void destroyChats()
+    {
+        for (auto *chat: m_chats) { chat->destroy(); }
+        ChatLLM::destroyStore();
+    }
 
     void removeChatFile(Chat *chat) const;
     Q_INVOKABLE void saveChats();