Complete revamp of model loading to allow for more discreet control by

the user of the models loading behavior.

Signed-off-by: Adam Treat <treat.adam@gmail.com>

gpt4all-backend/llamamodel.cpp

@@ -180,6 +180,9 @@ bool LLamaModel::loadModel(const std::string &modelPath, int n_ctx, int ngl)
     d_ptr->model_params.use_mlock = params.use_mlock;
 #endif
 
+    d_ptr->model_params.progress_callback = &LLModel::staticProgressCallback;
+    d_ptr->model_params.progress_callback_user_data = this;
+
 #ifdef GGML_USE_METAL
     if (llama_verbose()) {
         std::cerr << "llama.cpp: using Metal" << std::endl;

gpt4all-backend/llmodel.h

@@ -74,6 +74,8 @@ public:
         int32_t n_last_batch_tokens = 0;
     };
 
+    using ProgressCallback = std::function<bool(float progress)>;
+
     explicit LLModel() {}
     virtual ~LLModel() {}
 
@@ -125,6 +127,8 @@ public:
     virtual bool hasGPUDevice() { return false; }
     virtual bool usingGPUDevice() { return false; }
 
+    void setProgressCallback(ProgressCallback callback) { m_progressCallback = callback; }
+
 protected:
     // These are pure virtual because subclasses need to implement as the default implementation of
     // 'prompt' above calls these functions
@@ -153,6 +157,15 @@ protected:
 
     const Implementation *m_implementation = nullptr;
 
+    ProgressCallback m_progressCallback;
+    static bool staticProgressCallback(float progress, void* ctx)
+    {
+        LLModel* model = static_cast<LLModel*>(ctx);
+        if (model && model->m_progressCallback)
+            return model->m_progressCallback(progress);
+        return true;
+    }
+
 private:
     friend class LLMImplementation;
 };

gpt4all-chat/CMakeLists.txt

@@ -109,6 +109,7 @@ qt_add_qml_module(chat
       qml/ModelSettings.qml
       qml/ApplicationSettings.qml
       qml/LocalDocsSettings.qml
+      qml/SwitchModelDialog.qml
       qml/MySettingsTab.qml
       qml/MySettingsStack.qml
       qml/MySettingsDestructiveButton.qml
@@ -123,6 +124,7 @@ qt_add_qml_module(chat
       qml/MyTextField.qml
       qml/MyCheckBox.qml
       qml/MyBusyIndicator.qml
+      qml/MyMiniButton.qml
       qml/MyToolButton.qml
     RESOURCES
       icons/send_message.svg
@@ -133,6 +135,7 @@ qt_add_qml_module(chat
       icons/db.svg
       icons/download.svg
       icons/settings.svg
+      icons/eject.svg
       icons/edit.svg
       icons/image.svg
       icons/trash.svg

gpt4all-chat/chat.cpp

@@ -23,14 +23,10 @@ Chat::Chat(bool isServer, QObject *parent)
     , m_id(Network::globalInstance()->generateUniqueId())
     , m_name(tr("Server Chat"))
     , m_chatModel(new ChatModel(this))
-    , m_responseInProgress(false)
     , m_responseState(Chat::ResponseStopped)
     , m_creationDate(QDateTime::currentSecsSinceEpoch())
     , m_llmodel(new Server(this))
     , m_isServer(true)
-    , m_shouldDeleteLater(false)
-    , m_isModelLoaded(false)
-    , m_shouldLoadModelWhenInstalled(false)
     , m_collectionModel(new LocalDocsCollectionsModel(this))
 {
     connectLLM();
@@ -45,7 +41,7 @@ Chat::~Chat()
 void Chat::connectLLM()
 {
     // Should be in different threads
-    connect(m_llmodel, &ChatLLM::isModelLoadedChanged, this, &Chat::handleModelLoadedChanged, Qt::QueuedConnection);
+    connect(m_llmodel, &ChatLLM::modelLoadingPercentageChanged, this, &Chat::handleModelLoadingPercentageChanged, Qt::QueuedConnection);
     connect(m_llmodel, &ChatLLM::responseChanged, this, &Chat::handleResponseChanged, Qt::QueuedConnection);
     connect(m_llmodel, &ChatLLM::promptProcessing, this, &Chat::promptProcessing, Qt::QueuedConnection);
     connect(m_llmodel, &ChatLLM::responseStopped, this, &Chat::responseStopped, Qt::QueuedConnection);
@@ -57,6 +53,7 @@ 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(this, &Chat::promptRequested, m_llmodel, &ChatLLM::prompt, Qt::QueuedConnection);
     connect(this, &Chat::modelChangeRequested, m_llmodel, &ChatLLM::modelChangeRequested, Qt::QueuedConnection);
@@ -69,8 +66,6 @@ void Chat::connectLLM()
     connect(this, &Chat::processSystemPromptRequested, m_llmodel, &ChatLLM::processSystemPrompt, Qt::QueuedConnection);
 
     connect(this, &Chat::collectionListChanged, m_collectionModel, &LocalDocsCollectionsModel::setCollections);
-    connect(ModelList::globalInstance()->installedModels(), &InstalledModels::countChanged,
-        this, &Chat::handleModelInstalled, Qt::QueuedConnection);
 }
 
 void Chat::reset()
@@ -101,7 +96,12 @@ void Chat::processSystemPrompt()
 
 bool Chat::isModelLoaded() const
 {
-    return m_isModelLoaded;
+    return m_modelLoadingPercentage == 1.0f;
+}
+
+float Chat::modelLoadingPercentage() const
+{
+    return m_modelLoadingPercentage;
 }
 
 void Chat::resetResponseState()
@@ -158,15 +158,17 @@ void Chat::handleResponseChanged(const QString &response)
     emit responseChanged();
 }
 
-void Chat::handleModelLoadedChanged(bool loaded)
+void Chat::handleModelLoadingPercentageChanged(float loadingPercentage)
 {
     if (m_shouldDeleteLater)
         deleteLater();
 
-    if (loaded == m_isModelLoaded)
+    if (loadingPercentage == m_modelLoadingPercentage)
         return;
 
-    m_isModelLoaded = loaded;
+    m_modelLoadingPercentage = loadingPercentage;
+    emit modelLoadingPercentageChanged();
+    if (m_modelLoadingPercentage == 1.0f || m_modelLoadingPercentage == 0.0f)
         emit isModelLoadedChanged();
 }
 
@@ -238,10 +240,10 @@ ModelInfo Chat::modelInfo() const
 
 void Chat::setModelInfo(const ModelInfo &modelInfo)
 {
-    if (m_modelInfo == modelInfo)
+    if (m_modelInfo == modelInfo && isModelLoaded())
         return;
 
-    m_isModelLoaded = false;
+    m_modelLoadingPercentage = std::numeric_limits<float>::min();
     emit isModelLoadedChanged();
     m_modelLoadingError = QString();
     emit modelLoadingErrorChanged();
@@ -291,21 +293,26 @@ void Chat::unloadModel()
 
 void Chat::reloadModel()
 {
-    // If the installed model list is empty, then we mark a special flag and monitor for when a model
-    // is installed
-    if (!ModelList::globalInstance()->installedModels()->count()) {
-        m_shouldLoadModelWhenInstalled = true;
-        return;
-    }
     m_llmodel->setShouldBeLoaded(true);
 }
 
-void Chat::handleModelInstalled()
+void Chat::forceUnloadModel()
 {
-    if (!m_shouldLoadModelWhenInstalled)
+    stopGenerating();
-        return;
+    m_llmodel->setForceUnloadModel(true);
-    m_shouldLoadModelWhenInstalled = false;
+    m_llmodel->setShouldBeLoaded(false);
-    reloadModel();
+}
+
+void Chat::forceReloadModel()
+{
+    m_llmodel->setForceUnloadModel(true);
+    m_llmodel->setShouldBeLoaded(true);
+}
+
+void Chat::trySwitchContextOfLoadedModel()
+{
+    emit trySwitchContextOfLoadedModelAttempted();
+    m_llmodel->setShouldTrySwitchContext(true);
 }
 
 void Chat::generatedNameChanged(const QString &name)

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(float modelLoadingPercentage READ modelLoadingPercentage NOTIFY modelLoadingPercentageChanged)
     Q_PROPERTY(QString response READ response NOTIFY responseChanged)
     Q_PROPERTY(ModelInfo modelInfo READ modelInfo WRITE setModelInfo NOTIFY modelInfoChanged)
     Q_PROPERTY(bool responseInProgress READ responseInProgress NOTIFY responseInProgressChanged)
@@ -61,6 +62,7 @@ public:
     Q_INVOKABLE void reset();
     Q_INVOKABLE void processSystemPrompt();
     Q_INVOKABLE bool isModelLoaded() const;
+    Q_INVOKABLE float modelLoadingPercentage() const;
     Q_INVOKABLE void prompt(const QString &prompt);
     Q_INVOKABLE void regenerateResponse();
     Q_INVOKABLE void stopGenerating();
@@ -75,8 +77,11 @@ public:
     void setModelInfo(const ModelInfo &modelInfo);
     bool isRecalc() const;
 
-    void unloadModel();
+    Q_INVOKABLE void unloadModel();
-    void reloadModel();
+    Q_INVOKABLE void reloadModel();
+    Q_INVOKABLE void forceUnloadModel();
+    Q_INVOKABLE void forceReloadModel();
+    Q_INVOKABLE void trySwitchContextOfLoadedModel();
     void unloadAndDeleteLater();
 
     qint64 creationDate() const { return m_creationDate; }
@@ -106,6 +111,7 @@ Q_SIGNALS:
     void nameChanged();
     void chatModelChanged();
     void isModelLoadedChanged();
+    void modelLoadingPercentageChanged();
     void responseChanged();
     void responseInProgressChanged();
     void responseStateChanged();
@@ -127,10 +133,12 @@ Q_SIGNALS:
     void deviceChanged();
     void fallbackReasonChanged();
     void collectionModelChanged();
+    void trySwitchContextOfLoadedModelAttempted();
+    void trySwitchContextOfLoadedModelCompleted(bool);
 
 private Q_SLOTS:
     void handleResponseChanged(const QString &response);
-    void handleModelLoadedChanged(bool);
+    void handleModelLoadingPercentageChanged(float);
     void promptProcessing();
     void responseStopped();
     void generatedNameChanged(const QString &name);
@@ -141,7 +149,6 @@ private Q_SLOTS:
     void handleFallbackReasonChanged(const QString &device);
     void handleDatabaseResultsChanged(const QList<ResultInfo> &results);
     void handleModelInfoChanged(const ModelInfo &modelInfo);
-    void handleModelInstalled();
 
 private:
     QString m_id;
@@ -163,8 +170,7 @@ private:
     QList<ResultInfo> m_databaseResults;
     bool m_isServer = false;
     bool m_shouldDeleteLater = false;
-    bool m_isModelLoaded = false;
+    float m_modelLoadingPercentage = 0.0f;
-    bool m_shouldLoadModelWhenInstalled = false;
     LocalDocsCollectionsModel *m_collectionModel;
 };
 

gpt4all-chat/chatlistmodel.h

@@ -179,9 +179,9 @@ public:
         if (m_currentChat && m_currentChat != m_serverChat)
             m_currentChat->unloadModel();
         m_currentChat = chat;
-        if (!m_currentChat->isModelLoaded() && m_currentChat != m_serverChat)
-            m_currentChat->reloadModel();
         emit currentChatChanged();
+        if (!m_currentChat->isModelLoaded() && m_currentChat != m_serverChat)
+            m_currentChat->trySwitchContextOfLoadedModel();
     }
 
     Q_INVOKABLE Chat* get(int index)

gpt4all-chat/chatllm.cpp

@@ -62,7 +62,9 @@ ChatLLM::ChatLLM(Chat *parent, bool isServer)
     , m_promptResponseTokens(0)
     , m_promptTokens(0)
     , m_isRecalc(false)
-    , m_shouldBeLoaded(true)
+    , m_shouldBeLoaded(false)
+    , m_forceUnloadModel(false)
+    , m_shouldTrySwitchContext(false)
     , m_stopGenerating(false)
     , m_timer(nullptr)
     , m_isServer(isServer)
@@ -76,6 +78,8 @@ ChatLLM::ChatLLM(Chat *parent, bool isServer)
     connect(this, &ChatLLM::sendModelLoaded, Network::globalInstance(), &Network::sendModelLoaded);
     connect(this, &ChatLLM::shouldBeLoadedChanged, this, &ChatLLM::handleShouldBeLoadedChanged,
         Qt::QueuedConnection); // explicitly queued
+    connect(this, &ChatLLM::shouldTrySwitchContextChanged, this, &ChatLLM::handleShouldTrySwitchContextChanged,
+        Qt::QueuedConnection); // explicitly queued
     connect(parent, &Chat::idChanged, this, &ChatLLM::handleChatIdChanged);
     connect(&m_llmThread, &QThread::started, this, &ChatLLM::handleThreadStarted);
     connect(MySettings::globalInstance(), &MySettings::forceMetalChanged, this, &ChatLLM::handleForceMetalChanged);
@@ -143,6 +147,54 @@ bool ChatLLM::loadDefaultModel()
     return loadModel(defaultModel);
 }
 
+bool ChatLLM::trySwitchContextOfLoadedModel(const ModelInfo &modelInfo)
+{
+    // We're trying to see if the store already has the model fully loaded that we wish to use
+    // and if so we just acquire it from the store and switch the context and return true. If the
+    // store doesn't have it or we're already loaded or in any other case just return false.
+
+    // If we're already loaded or a server or we're reloading to change the variant/device or the
+    // modelInfo is empty, then this should fail
+    if (isModelLoaded() || m_isServer || m_reloadingToChangeVariant || modelInfo.name().isEmpty()) {
+        m_shouldTrySwitchContext = false;
+        emit trySwitchContextOfLoadedModelCompleted(false);
+        return false;
+    }
+
+    QString filePath = modelInfo.dirpath + modelInfo.filename();
+    QFileInfo fileInfo(filePath);
+
+    m_llModelInfo = LLModelStore::globalInstance()->acquireModel();
+#if defined(DEBUG_MODEL_LOADING)
+        qDebug() << "acquired model from store" << m_llmThread.objectName() << m_llModelInfo.model;
+#endif
+
+    // The store gave us no already loaded model, the wrong type of model, then give it back to the
+    // store and fail
+    if (!m_llModelInfo.model || m_llModelInfo.fileInfo != fileInfo) {
+        LLModelStore::globalInstance()->releaseModel(m_llModelInfo);
+        m_llModelInfo = LLModelInfo();
+        m_shouldTrySwitchContext = false;
+        emit trySwitchContextOfLoadedModelCompleted(false);
+        return false;
+    }
+
+#if defined(DEBUG_MODEL_LOADING)
+    qDebug() << "store had our model" << m_llmThread.objectName() << m_llModelInfo.model;
+#endif
+
+    // We should be loaded and now we are
+    m_shouldBeLoaded = true;
+    m_shouldTrySwitchContext = false;
+
+    // Restore, signal and process
+    restoreState();
+    emit modelLoadingPercentageChanged(1.0f);
+    emit trySwitchContextOfLoadedModelCompleted(true);
+    processSystemPrompt();
+    return true;
+}
+
 bool ChatLLM::loadModel(const ModelInfo &modelInfo)
 {
     // This is a complicated method because N different possible threads are interested in the outcome
@@ -170,7 +222,7 @@ bool ChatLLM::loadModel(const ModelInfo &modelInfo)
 #endif
         delete m_llModelInfo.model;
         m_llModelInfo.model = nullptr;
-        emit isModelLoadedChanged(false);
+        emit modelLoadingPercentageChanged(std::numeric_limits<float>::min());
     } else if (!m_isServer) {
         // This is a blocking call that tries to retrieve the model we need from the model store.
         // If it succeeds, then we just have to restore state. If the store has never had a model
@@ -188,7 +240,7 @@ bool ChatLLM::loadModel(const ModelInfo &modelInfo)
 #endif
             LLModelStore::globalInstance()->releaseModel(m_llModelInfo);
             m_llModelInfo = LLModelInfo();
-            emit isModelLoadedChanged(false);
+            emit modelLoadingPercentageChanged(0.0f);
             return false;
         }
 
@@ -198,7 +250,7 @@ bool ChatLLM::loadModel(const ModelInfo &modelInfo)
             qDebug() << "store had our model" << m_llmThread.objectName() << m_llModelInfo.model;
 #endif
             restoreState();
-            emit isModelLoadedChanged(true);
+            emit modelLoadingPercentageChanged(1.0f);
             setModelInfo(modelInfo);
             Q_ASSERT(!m_modelInfo.filename().isEmpty());
             if (m_modelInfo.filename().isEmpty())
@@ -261,6 +313,12 @@ bool ChatLLM::loadModel(const ModelInfo &modelInfo)
             m_llModelInfo.model = LLModel::Implementation::construct(filePath.toStdString(), buildVariant, n_ctx);
 
             if (m_llModelInfo.model) {
+
+                m_llModelInfo.model->setProgressCallback([this](float progress) -> bool {
+                    emit modelLoadingPercentageChanged(progress);
+                    return m_shouldBeLoaded;
+                });
+
                 // Update the settings that a model is being loaded and update the device list
                 MySettings::globalInstance()->setAttemptModelLoad(filePath);
 
@@ -354,7 +412,7 @@ bool ChatLLM::loadModel(const ModelInfo &modelInfo)
         qDebug() << "modelLoadedChanged" << m_llmThread.objectName();
         fflush(stdout);
 #endif
-        emit isModelLoadedChanged(isModelLoaded());
+        emit modelLoadingPercentageChanged(isModelLoaded() ? 1.0f : 0.0f);
 
         static bool isFirstLoad = true;
         if (isFirstLoad) {
@@ -456,6 +514,7 @@ void ChatLLM::setModelInfo(const ModelInfo &modelInfo)
 
 void ChatLLM::modelChangeRequested(const ModelInfo &modelInfo)
 {
+    m_shouldBeLoaded = true;
     loadModel(modelInfo);
 }
 
@@ -598,6 +657,12 @@ void ChatLLM::setShouldBeLoaded(bool b)
     emit shouldBeLoadedChanged();
 }
 
+void ChatLLM::setShouldTrySwitchContext(bool b)
+{
+    m_shouldTrySwitchContext = b; // atomic
+    emit shouldTrySwitchContextChanged();
+}
+
 void ChatLLM::handleShouldBeLoadedChanged()
 {
     if (m_shouldBeLoaded)
@@ -606,10 +671,10 @@ void ChatLLM::handleShouldBeLoadedChanged()
         unloadModel();
 }
 
-void ChatLLM::forceUnloadModel()
+void ChatLLM::handleShouldTrySwitchContextChanged()
 {
-    m_shouldBeLoaded = false; // atomic
+    if (m_shouldTrySwitchContext)
-    unloadModel();
+        trySwitchContextOfLoadedModel(modelInfo());
 }
 
 void ChatLLM::unloadModel()
@@ -617,17 +682,27 @@ void ChatLLM::unloadModel()
     if (!isModelLoaded() || m_isServer)
         return;
 
+    emit modelLoadingPercentageChanged(0.0f);
     saveState();
 #if defined(DEBUG_MODEL_LOADING)
     qDebug() << "unloadModel" << m_llmThread.objectName() << m_llModelInfo.model;
 #endif
+
+    if (m_forceUnloadModel) {
+        delete m_llModelInfo.model;
+        m_llModelInfo.model = nullptr;
+        m_forceUnloadModel = false;
+    }
+
     LLModelStore::globalInstance()->releaseModel(m_llModelInfo);
     m_llModelInfo = LLModelInfo();
-    emit isModelLoadedChanged(false);
 }
 
 void ChatLLM::reloadModel()
 {
+    if (isModelLoaded() && m_forceUnloadModel)
+        unloadModel(); // we unload first if we are forcing an unload
+
     if (isModelLoaded() || m_isServer)
         return;
 

gpt4all-chat/chatllm.h

@@ -81,6 +81,8 @@ public:
 
     bool shouldBeLoaded() const { return m_shouldBeLoaded; }
     void setShouldBeLoaded(bool b);
+    void setShouldTrySwitchContext(bool b);
+    void setForceUnloadModel(bool b) { m_forceUnloadModel = b; }
 
     QString response() const;
 
@@ -98,14 +100,15 @@ public:
 public Q_SLOTS:
     bool prompt(const QList<QString> &collectionList, const QString &prompt);
     bool loadDefaultModel();
+    bool trySwitchContextOfLoadedModel(const ModelInfo &modelInfo);
     bool loadModel(const ModelInfo &modelInfo);
     void modelChangeRequested(const ModelInfo &modelInfo);
-    void forceUnloadModel();
     void unloadModel();
     void reloadModel();
     void generateName();
     void handleChatIdChanged(const QString &id);
     void handleShouldBeLoadedChanged();
+    void handleShouldTrySwitchContextChanged();
     void handleThreadStarted();
     void handleForceMetalChanged(bool forceMetal);
     void handleDeviceChanged();
@@ -114,7 +117,7 @@ public Q_SLOTS:
 
 Q_SIGNALS:
     void recalcChanged();
-    void isModelLoadedChanged(bool);
+    void modelLoadingPercentageChanged(float);
     void modelLoadingError(const QString &error);
     void responseChanged(const QString &response);
     void promptProcessing();
@@ -125,6 +128,8 @@ Q_SIGNALS:
     void stateChanged();
     void threadStarted();
     void shouldBeLoadedChanged();
+    void shouldTrySwitchContextChanged();
+    void trySwitchContextOfLoadedModelCompleted(bool);
     void requestRetrieveFromDB(const QList<QString> &collections, const QString &text, int retrievalSize, QList<ResultInfo> *results);
     void reportSpeed(const QString &speed);
     void reportDevice(const QString &device);
@@ -167,7 +172,9 @@ private:
     QThread m_llmThread;
     std::atomic<bool> m_stopGenerating;
     std::atomic<bool> m_shouldBeLoaded;
+    std::atomic<bool> m_shouldTrySwitchContext;
     std::atomic<bool> m_isRecalc;
+    std::atomic<bool> m_forceUnloadModel;
     bool m_isServer;
     bool m_forceMetal;
     bool m_reloadingToChangeVariant;

gpt4all-chat/icons/eject.svg

@@ -0,0 +1,6 @@
+
+<svg xmlns="http://www.w3.org/2000/svg" fill="#7d7d8e" viewBox="0 0 448 512"><path d="M448 384v64c0 17.673-14.327 32-32 32H32c-17.673 0-32-14.327-32-32v-64c0-17.673 14.327-32 32-32h384c17.673 0 32 14.327 32 32zM48.053 320h351.886c41.651 0 63.581-49.674 35.383-80.435L259.383 47.558c-19.014-20.743-51.751-20.744-70.767 0L12.67 239.565C-15.475 270.268 6.324 320 48.053 320z"/></svg>
+<!--
+Font Awesome Free 5.2.0 by @fontawesome - https://fontawesome.com
+License - https://fontawesome.com/license (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License)
+-->

gpt4all-chat/main.qml

@@ -126,6 +126,10 @@ Window {
         }
     }
 
+    function currentModelName() {
+        return ModelList.modelInfo(currentChat.modelInfo.id).name;
+    }
+
     PopupDialog {
         id: errorCompatHardware
         anchors.centerIn: parent
@@ -282,6 +286,18 @@ Window {
         }
     }
 
+    SwitchModelDialog {
+        id: switchModelDialog
+        anchors.centerIn: parent
+        width: Math.min(1024, window.width - (window.width * .2))
+        height: Math.min(600, window.height - (window.height * .2))
+        Item {
+            Accessible.role: Accessible.Dialog
+            Accessible.name: qsTr("Switch model dialog")
+            Accessible.description: qsTr("Warn the user if they switch models, then context will be erased")
+        }
+    }
+
     Rectangle {
         id: header
         anchors.left: parent.left
@@ -292,7 +308,9 @@ Window {
         Item {
             anchors.centerIn: parent
             height: childrenRect.height
-            visible: currentChat.isModelLoaded || currentChat.modelLoadingError !== "" || currentChat.isServer
+            visible: true
+                || currentChat.modelLoadingError !== ""
+                || currentChat.isServer
 
             Label {
                 id: modelLabel
@@ -306,46 +324,92 @@ Window {
                 horizontalAlignment: TextInput.AlignRight
             }
 
-            MyComboBox {
+            RowLayout {
-                id: comboBox
+                id: comboLayout
-                implicitWidth: 375
-                width: window.width >= 750 ? implicitWidth : implicitWidth - ((750 - window.width))
                 anchors.top: modelLabel.top
                 anchors.bottom: modelLabel.bottom
                 anchors.horizontalCenter: parent.horizontalCenter
                 anchors.horizontalCenterOffset: window.width >= 950 ? 0 : Math.max(-((950 - window.width) / 2), -99.5)
+                spacing: 20
+
+                MyComboBox {
+                    id: comboBox
+                    Layout.fillWidth: true
+                    Layout.fillHeight: true
+                    implicitWidth: 575
+                    width: window.width >= 750 ? implicitWidth : implicitWidth - ((750 - window.width))
                     enabled: !currentChat.isServer
                     model: ModelList.installedModels
                     valueRole: "id"
                     textRole: "name"
-                property string currentModelName: ""
+                    property bool isCurrentlyLoading: false
-                function updateCurrentModelName() {
+                    property real modelLoadingPercentage: 0.0
-                    var info = ModelList.modelInfo(currentChat.modelInfo.id);
+                    property bool trySwitchContextInProgress: false
-                    comboBox.currentModelName = info.name;
+
+                    function changeModel(index) {
+                        comboBox.modelLoadingPercentage = 0.0;
+                        comboBox.isCurrentlyLoading = true;
+                        currentChat.stopGenerating()
+                        currentChat.reset();
+                        currentChat.modelInfo = ModelList.modelInfo(comboBox.valueAt(index))
                     }
+
                     Connections {
                         target: currentChat
-                    function onModelInfoChanged() {
+                        function onModelLoadingPercentageChanged() {
-                        comboBox.updateCurrentModelName();
+                            comboBox.modelLoadingPercentage = currentChat.modelLoadingPercentage;
+                            comboBox.isCurrentlyLoading = currentChat.modelLoadingPercentage !== 0.0
+                                && currentChat.modelLoadingPercentage !== 1.0;
+                        }
+                        function onTrySwitchContextOfLoadedModelAttempted() {
+                            comboBox.trySwitchContextInProgress = true;
+                        }
+                        function onTrySwitchContextOfLoadedModelCompleted() {
+                            comboBox.trySwitchContextInProgress = false;
                         }
                     }
                     Connections {
-                    target: window
+                        target: switchModelDialog
-                    function onCurrentChatChanged() {
+                        function onAccepted() {
-                        comboBox.updateCurrentModelName();
+                            comboBox.changeModel(switchModelDialog.index)
                         }
                     }
+
+                    background: ProgressBar {
+                        id: modelProgress
+                        value: comboBox.modelLoadingPercentage
                         background: Rectangle {
                             color: theme.mainComboBackground
                             radius: 10
                         }
+                        contentItem: Item {
+                            Rectangle {
+                                visible: comboBox.isCurrentlyLoading
+                                anchors.bottom: parent.bottom
+                                width: modelProgress.visualPosition * parent.width
+                                height: 10
+                                radius: 2
+                                color: theme.progressForeground
+                            }
+                        }
+                    }
                     contentItem: Text {
                         anchors.horizontalCenter: parent.horizontalCenter
                         leftPadding: 10
                         rightPadding: 20
-                    text: currentChat.modelLoadingError !== ""
+                        text: {
-                        ? qsTr("Model loading error...")
+                            if (currentChat.modelLoadingError !== "")
-                        : comboBox.currentModelName
+                                return qsTr("Model loading error...")
+                            if (comboBox.trySwitchContextInProgress)
+                                return qsTr("Switching context...")
+                            if (currentModelName() === "")
+                                return qsTr("Choose a model...")
+                            if (currentChat.modelLoadingPercentage === 0.0)
+                                return qsTr("Reload \u00B7 ") + currentModelName()
+                            if (comboBox.isCurrentlyLoading)
+                                return qsTr("Loading \u00B7 ") + currentModelName()
+                            return currentModelName()
+                        }
                         font.pixelSize: theme.fontSizeLarger
                         color: theme.white
                         verticalAlignment: Text.AlignVCenter
@@ -353,6 +417,7 @@ Window {
                         elide: Text.ElideRight
                     }
                     delegate: ItemDelegate {
+                        id: comboItemDelegate
                         width: comboBox.width
                         contentItem: Text {
                             text: name
@@ -369,39 +434,58 @@ Window {
                         highlighted: comboBox.highlightedIndex === index
                     }
                     Accessible.role: Accessible.ComboBox
-                Accessible.name: comboBox.currentModelName
+                    Accessible.name: currentModelName()
                     Accessible.description: qsTr("The top item is the current model")
                     onActivated: function (index) {
-                    currentChat.stopGenerating()
+                        var newInfo = ModelList.modelInfo(comboBox.valueAt(index));
-                    currentChat.reset();
+                        if (currentModelName() !== ""
-                    currentChat.modelInfo = ModelList.modelInfo(comboBox.valueAt(index))
+                            && newInfo !== currentChat.modelInfo
-                }
+                            && chatModel.count !== 0) {
+                            switchModelDialog.index = index;
+                            switchModelDialog.open();
+                        } else {
+                            comboBox.changeModel(index);
                         }
                     }
 
-        Item {
+                    MyMiniButton {
-            anchors.centerIn: parent
+                        id: ejectButton
-            visible: ModelList.installedModels.count
+                        visible: currentChat.isModelLoaded
-                && !currentChat.isModelLoaded
+                        z: 500
-                && currentChat.modelLoadingError === ""
+                        anchors.right: parent.right
-                && !currentChat.isServer
+                        anchors.rightMargin: 50
-            width: childrenRect.width
-            height: childrenRect.height
-            Row {
-                spacing: 5
-                MyBusyIndicator {
                         anchors.verticalCenter: parent.verticalCenter
-                    running: parent.visible
+                        source: "qrc:/gpt4all/icons/eject.svg"
-                    Accessible.role: Accessible.Animation
+                        backgroundColor: theme.gray300
-                    Accessible.name: qsTr("Busy indicator")
+                        backgroundColorHovered: theme.iconBackgroundLight
-                    Accessible.description: qsTr("loading model...")
+                        onClicked: {
+                            currentChat.forceUnloadModel();
+                        }
+                        ToolTip.text: qsTr("Eject the currently loaded model")
+                        ToolTip.visible: hovered
                     }
 
-                Label {
+                    MyMiniButton {
+                        id: reloadButton
+                        visible: currentChat.modelLoadingError === ""
+                            && !comboBox.trySwitchContextInProgress
+                            && (currentChat.isModelLoaded || currentModelName() !== "")
+                        z: 500
+                        anchors.right: ejectButton.visible ? ejectButton.left : parent.right
+                        anchors.rightMargin: ejectButton.visible ? 10 : 50
                         anchors.verticalCenter: parent.verticalCenter
-                    text: qsTr("Loading model...")
+                        source: "qrc:/gpt4all/icons/regenerate.svg"
-                    font.pixelSize: theme.fontSizeLarge
+                        backgroundColor: theme.gray300
-                    color: theme.oppositeTextColor
+                        backgroundColorHovered: theme.iconBackgroundLight
+                        onClicked: {
+                            if (currentChat.isModelLoaded)
+                                currentChat.forceReloadModel();
+                            else
+                                currentChat.reloadModel();
+                        }
+                        ToolTip.text: qsTr("Reload the currently loaded model")
+                        ToolTip.visible: hovered
+                    }
                 }
             }
         }
@@ -790,9 +874,9 @@ Window {
 
                 Rectangle {
                     id: homePage
-                    color: "transparent"//theme.green200
+                    color: "transparent"
                     anchors.fill: parent
-                    visible: (ModelList.installedModels.count === 0 || chatModel.count === 0) && !currentChat.isServer
+                    visible: !currentChat.isModelLoaded && (ModelList.installedModels.count === 0 || currentModelName() === "") && !currentChat.isServer
 
                     ColumnLayout {
                         anchors.centerIn: parent
@@ -1138,10 +1222,14 @@ Window {
             }
         }
 
+        RowLayout {
+            anchors.bottom: textInputView.top
+            anchors.horizontalCenter: textInputView.horizontalCenter
+            anchors.bottomMargin: 20
+            spacing: 10
             MyButton {
-            id: myButton
-            visible: chatModel.count && !currentChat.isServer
                 textColor: theme.textColor
+                visible: chatModel.count && !currentChat.isServer && currentChat.isModelLoaded
                 Image {
                     anchors.verticalCenter: parent.verticalCenter
                     anchors.left: parent.left
@@ -1170,20 +1258,50 @@ Window {
                         }
                     }
                 }
-            background: Rectangle {
+
-                border.color: theme.conversationButtonBorder
+                borderWidth: 1
-                border.width: 2
+                backgroundColor: theme.conversationButtonBackground
-                radius: 10
+                backgroundColorHovered: theme.conversationButtonBackgroundHovered
-                color: myButton.hovered ? theme.conversationButtonBackgroundHovered : theme.conversationButtonBackground
+                backgroundRadius: 5
-            }
-            anchors.bottom: textInputView.top
-            anchors.horizontalCenter: textInputView.horizontalCenter
-            anchors.bottomMargin: 20
                 padding: 15
+                topPadding: 4
+                bottomPadding: 4
                 text: currentChat.responseInProgress ? qsTr("Stop generating") : qsTr("Regenerate response")
+                fontPixelSize: theme.fontSizeSmaller
                 Accessible.description: qsTr("Controls generation of the response")
             }
 
+            MyButton {
+                textColor: theme.textColor
+                visible: chatModel.count
+                    && !currentChat.isServer
+                    && !currentChat.isModelLoaded
+                    && currentChat.modelLoadingPercentage === 0.0
+                    && currentChat.modelInfo.name !== ""
+                Image {
+                    anchors.verticalCenter: parent.verticalCenter
+                    anchors.left: parent.left
+                    anchors.leftMargin: 15
+                    source: "qrc:/gpt4all/icons/regenerate.svg"
+                }
+                leftPadding: 50
+                onClicked: {
+                    currentChat.reloadModel();
+                }
+
+                borderWidth: 1
+                backgroundColor: theme.conversationButtonBackground
+                backgroundColorHovered: theme.conversationButtonBackgroundHovered
+                backgroundRadius: 5
+                padding: 15
+                topPadding: 4
+                bottomPadding: 4
+                text: qsTr("Reload \u00B7 ") + currentChat.modelInfo.name
+                fontPixelSize: theme.fontSizeSmaller
+                Accessible.description: qsTr("Reloads the model")
+            }
+        }
+
         Text {
             id: device
             anchors.bottom: textInputView.top
@@ -1224,7 +1342,7 @@ Window {
                 rightPadding: 40
                 enabled: currentChat.isModelLoaded && !currentChat.isServer
                 font.pixelSize: theme.fontSizeLarger
-                placeholderText: qsTr("Send a message...")
+                placeholderText: currentChat.isModelLoaded ? qsTr("Send a message...") : qsTr("Load a model to continue...")
                 Accessible.role: Accessible.EditableText
                 Accessible.name: placeholderText
                 Accessible.description: qsTr("Send messages/prompts to the model")

gpt4all-chat/qml/MyButton.qml

@@ -13,6 +13,7 @@ Button {
     property color mutedTextColor: theme.oppositeMutedTextColor
     property color backgroundColor: theme.buttonBackground
     property color backgroundColorHovered: theme.buttonBackgroundHovered
+    property real  backgroundRadius: 10
     property real  borderWidth: MySettings.chatTheme === "LegacyDark" ? 1 : 0
     property color borderColor: theme.buttonBorder
     property real  fontPixelSize: theme.fontSizeLarge
@@ -25,7 +26,7 @@ Button {
         Accessible.name: text
     }
     background: Rectangle {
-        radius: 10
+        radius: myButton.backgroundRadius
         border.width: myButton.borderWidth
         border.color: myButton.borderColor
         color: myButton.hovered ? backgroundColorHovered : backgroundColor

gpt4all-chat/qml/MyMiniButton.qml

@@ -0,0 +1,47 @@
+import QtCore
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Controls.Basic
+import Qt5Compat.GraphicalEffects
+
+Button {
+    id: myButton
+    padding: 0
+    property color backgroundColor: theme.iconBackgroundDark
+    property color backgroundColorHovered: theme.iconBackgroundHovered
+    property alias source: image.source
+    property alias fillMode: image.fillMode
+    width: 30
+    height: 30
+    contentItem: Text {
+        text: myButton.text
+        horizontalAlignment: Text.AlignHCenter
+        color: myButton.enabled ? theme.textColor : theme.mutedTextColor
+        font.pixelSize: theme.fontSizeLarge
+        Accessible.role: Accessible.Button
+        Accessible.name: text
+    }
+
+    background: Item {
+        anchors.fill: parent
+        Rectangle {
+            anchors.fill: parent
+            color: "transparent"
+        }
+        Image {
+            id: image
+            anchors.centerIn: parent
+            mipmap: true
+            width: 20
+            height: 20
+        }
+        ColorOverlay {
+            anchors.fill: image
+            source: image
+            color: myButton.hovered ? backgroundColorHovered : backgroundColor
+        }
+    }
+    Accessible.role: Accessible.Button
+    Accessible.name: text
+    ToolTip.delay: Qt.styleHints.mousePressAndHoldInterval
+}

gpt4all-chat/qml/SwitchModelDialog.qml

@@ -0,0 +1,44 @@
+import QtCore
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Controls.Basic
+import QtQuick.Layouts
+import llm
+import mysettings
+
+MyDialog {
+    id: switchModelDialog
+    anchors.centerIn: parent
+    modal: true
+    padding: 20
+    property int index: -1
+
+    Theme {
+        id: theme
+    }
+
+    Column {
+        id: column
+        spacing: 20
+    }
+
+    footer: DialogButtonBox {
+        id: dialogBox
+        padding: 20
+        alignment: Qt.AlignRight
+        spacing: 10
+        MySettingsButton {
+            text: qsTr("Continue")
+            Accessible.description: qsTr("Continue with model loading")
+            DialogButtonBox.buttonRole: DialogButtonBox.AcceptRole
+        }
+        MySettingsButton {
+            text: qsTr("Cancel")
+            Accessible.description: qsTr("Cancel")
+            DialogButtonBox.buttonRole: DialogButtonBox.RejectRole
+        }
+        background: Rectangle {
+            color: "transparent"
+        }
+    }
+}

gpt4all-chat/qml/Theme.qml

@@ -555,6 +555,7 @@ QtObject {
     property real fontSizeFixedSmall: 16
     property real fontSize: Qt.application.font.pixelSize
 
+    property real fontSizeSmaller: fontSizeLarge - 4
     property real fontSizeSmall: fontSizeLarge - 2
     property real  fontSizeLarge: MySettings.fontSize === "Small" ?
         fontSize : MySettings.fontSize === "Medium" ?