refactor: 全局共享 STT 模型，避免重复加载

将 SenseVoiceEngine 提升为 Application 级别的全局单例，应用启动时
异步加载一次模型，实时语音识别、文件转写和快捷键语音输入共享同一实例。

- Application 创建并管理全局 SenseVoiceEngine，启动时加载模型
- STTTestPage、FileTranscribePage、VoiceInputService 不再各自
  创建引擎，改为接收全局实例
- 移除各模块中冗余的 loadModel/loadModelAsync/unloadModel 调用
- 模型未加载时提供友好的等待提示，而非加载失败的错误弹窗

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/application.cpp

@@ -1,5 +1,6 @@
 #include "application.h"
 #include "config_manager.h"
+#include "core/sense_voice_engine.h"
 #include "utils/logger.h"
 #include <QFile>
 
@@ -14,6 +15,22 @@ Application::Application(int& argc, char** argv)
 
     configManager_ = std::make_unique<ConfigManager>(this);
     configManager_->loadDefaults();
+
+    // 创建全局 STT 引擎（共享实例）
+    sttEngine_ = new SenseVoiceEngine(this);
+    connect(sttEngine_, &SenseVoiceEngine::modelLoaded, this, [this](const QString& path) {
+        modelLoaded_ = true;
+        LOG_INFO(kTag, QString("全局模型已加载: %1").arg(path));
+        emit modelLoaded();
+    });
+    connect(sttEngine_, &SenseVoiceEngine::modelLoadError, this, [this](const QString&, const QString& err) {
+        modelLoaded_ = false;
+        LOG_ERROR(kTag, QString("全局模型加载失败: %1").arg(err));
+        emit modelLoadError(err);
+    });
+
+    // 异步加载全局模型
+    loadGlobalModel();
 }
 
 Application::~Application() {
@@ -25,4 +42,30 @@ ConfigManager* Application::configManager() const {
     return configManager_.get();
 }
 
+SenseVoiceEngine* Application::sttEngine() const {
+    return sttEngine_;
+}
+
+bool Application::isModelLoaded() const {
+    return modelLoaded_;
+}
+
+void Application::loadGlobalModel() {
+    QString modelPath = configManager_->get("stt.model_path").toString();
+    if (modelPath.isEmpty()) {
+        LOG_WARNING(kTag, "模型路径为空，请在配置中设置后重启");
+        return;
+    }
+
+    QString tokensPath = configManager_->get("stt.tokens_path").toString();
+    QString device = configManager_->get("stt.device").toString();
+    int numThreads = configManager_->get("stt.num_threads").toInt();
+
+    bool debugSave = configManager_->get("stt.debug_save_audio").toBool();
+    sttEngine_->setDebugSaveAudio(debugSave);
+
+    LOG_INFO(kTag, QString("正在异步加载全局模型: %1").arg(modelPath));
+    sttEngine_->loadModelAsync(modelPath, tokensPath, device, numThreads);
+}
+
 } // namespace impress

src/app/application.h

@@ -6,9 +6,13 @@
 namespace impress {
 
 class ConfigManager;
+class SenseVoiceEngine;
 
 /**
  * @brief 应用入口封装
+ *
+ * 管理全局共享组件：配置管理器、STT 引擎。
+ * STT 引擎在启动时异步加载模型，所有页面和服务共享同一实例。
  */
 class Application : public QApplication {
     Q_OBJECT
@@ -19,8 +23,25 @@ public:
     /** @brief 获取全局配置管理器 */
     ConfigManager* configManager() const;
 
+    /** @brief 获取全局 STT 引擎（共享实例） */
+    SenseVoiceEngine* sttEngine() const;
+
+    /** @brief 获取全局 STT 引擎加载状态 */
+    bool isModelLoaded() const;
+
+signals:
+    /** @brief 模型加载完成 */
+    void modelLoaded();
+
+    /** @brief 模型加载失败 */
+    void modelLoadError(const QString& error);
+
 private:
+    void loadGlobalModel();
+
     std::unique_ptr<ConfigManager> configManager_;
+    SenseVoiceEngine* sttEngine_ = nullptr;
+    bool modelLoaded_ = false;
 };
 
 } // namespace impress

src/core/voice_input_service.cpp

@@ -31,11 +31,14 @@ struct VoiceInputService::Impl {
     WaylandTextInjector* injector = nullptr;
 };
 
-VoiceInputService::VoiceInputService(ConfigManager* configManager, QObject* parent)
+VoiceInputService::VoiceInputService(ConfigManager* configManager,
+                                     SenseVoiceEngine* sttEngine,
+                                     QObject* parent)
     : QObject(parent)
     , configManager_(configManager)
     , impl_(std::make_unique<Impl>())
 {
+    impl_->sttEngine = sttEngine;
     longPressTimer_ = new QTimer(this);
     longPressTimer_->setSingleShot(true);
     connect(longPressTimer_, &QTimer::timeout, this, [this]() {
@@ -59,30 +62,7 @@ bool VoiceInputService::start() {
     connect(impl_->audioCapture, &AudioCapture::audioDataReady,
             this, &VoiceInputService::onAudioData);
 
-    // 2. 初始化 STT 引擎并加载模型
+    // 2. STT 引擎已作为参数传入（共享全局实例）
-    impl_->sttEngine = new SenseVoiceEngine(this);
-
-    // 从配置加载模型
-    QString modelPath = configManager_->get("stt.model_path").toString();
-    QString tokensPath = configManager_->get("stt.tokens_path").toString();
-    QString device = configManager_->get("stt.device").toString();
-    int numThreads = configManager_->get("stt.num_threads").toInt();
-
-    if (!modelPath.isEmpty()) {
-        LOG_INFO(kTag, QString("正在加载 STT 模型: %1").arg(modelPath));
-        bool modelLoaded = impl_->sttEngine->loadModelSync(modelPath, tokensPath, device, numThreads);
-        if (!modelLoaded) {
-            emit error(QString("STT 模型加载失败: %1").arg(modelPath));
-            LOG_ERROR(kTag, "STT 模型加载失败");
-        } else {
-            LOG_INFO(kTag, "STT 模型加载成功");
-            // 同步调试音频设置
-            bool debugSave = configManager_->get("stt.debug_save_audio").toBool();
-            impl_->sttEngine->setDebugSaveAudio(debugSave);
-        }
-    } else {
-        LOG_WARNING(kTag, "模型路径为空，请先在配置中设置模型路径");
-    }
 
     // 3. 初始化全局快捷键
     impl_->hotkey = new CapsLockVoiceHotkey(this);
@@ -124,9 +104,6 @@ void VoiceInputService::stop() {
     if (impl_->audioCapture) {
         impl_->audioCapture->stop();
     }
-    if (impl_->sttEngine) {
-        impl_->sttEngine->unloadModel();
-    }
     if (impl_->hotkey) {
         impl_->hotkey->stop();
     }

src/core/voice_input_service.h

@@ -27,7 +27,9 @@ class ConfigManager;
 class VoiceInputService : public QObject {
     Q_OBJECT
 public:
-    explicit VoiceInputService(ConfigManager* configManager, QObject* parent = nullptr);
+    explicit VoiceInputService(ConfigManager* configManager,
+                               SenseVoiceEngine* sttEngine,
+                               QObject* parent = nullptr);
     ~VoiceInputService() override;
 
     /** @brief 启动服务（初始化所有组件） */

src/main.cpp

@@ -56,8 +56,8 @@ int main(int argc, char* argv[])
         configManager->set("stt.model_path", modelPath);
     }
 
-    // 创建并显示主窗口
+    // 创建并显示主窗口（传入全局引擎）
-    impress::MainWindow mainWindow(configManager);
+    impress::MainWindow mainWindow(configManager, app.sttEngine());
     mainWindow.show();
 
     return app.exec();

src/ui/file_transcribe_page.cpp

@@ -31,10 +31,12 @@ static const char* const kTag = "FileTranscribePage";
 
 namespace impress {
 
-FileTranscribePage::FileTranscribePage(ConfigManager* configManager, QWidget* parent)
+FileTranscribePage::FileTranscribePage(ConfigManager* configManager,
+                                       SenseVoiceEngine* sttEngine,
+                                       QWidget* parent)
     : QWidget(parent)
     , configManager_(configManager)
-    , sttEngine_(new SenseVoiceEngine(this))
+    , sttEngine_(sttEngine)
     , audioDecoder_(new AudioDecoder(this))
 {
     setupUI();
@@ -148,29 +150,10 @@ void FileTranscribePage::onStartTranscribe() {
         return;
     }
 
-    QString modelPath = configManager_->get("stt.model_path").toString();
+    // 检查全局模型是否已加载
-    if (modelPath.isEmpty()) {
+    if (!sttEngine_->isLoaded()) {
-        QMessageBox::warning(this, "提示", "请先在配置页面设置模型路径");
+        QMessageBox::warning(this, "提示",
-        return;
+            "模型尚未加载完成，请稍候再试");
-    }
-
-    // 在后台线程中加载模型（不阻塞 UI）
-    statusLabel_->setText("正在加载模型...");
-    startBtn_->setEnabled(false);
-    activeWorkers_ = 1; // 标记正在加载模型
-
-    (void)QtConcurrent::run([this, modelPath]() {
-        bool success = sttEngine_->loadModelSync(modelPath,
-            configManager_->get("stt.tokens_path").toString(),
-            configManager_->get("stt.device").toString(),
-            configManager_->get("stt.num_threads").toInt());
-
-        QMetaObject::invokeMethod(this, [this, success]() {
-            activeWorkers_--;
-            if (!success) {
-                QMessageBox::critical(this, "错误", "模型加载失败");
-                statusLabel_->setText("模型加载失败");
-                startBtn_->setEnabled(true);
         return;
     }
 
@@ -186,8 +169,6 @@ void FileTranscribePage::onStartTranscribe() {
 
     // 启动后台转写队列
     startBatchTranscription();
-        }, Qt::QueuedConnection);
-    });
 }
 
 void FileTranscribePage::onStopTranscribe() {
@@ -195,7 +176,6 @@ void FileTranscribePage::onStopTranscribe() {
     activeWorkers_ = 0;
     progressBar_->setVisible(false);
     statusLabel_->setText("已停止");
-    sttEngine_->unloadModel();
     updateUIState();
 }
 
@@ -296,7 +276,6 @@ void FileTranscribePage::onAllComplete() {
     isTranscribing_ = false;
     statusLabel_->setText("全部完成");
     progressBar_->setVisible(false);
-    sttEngine_->unloadModel();
     updateUIState();
 }
 

src/ui/file_transcribe_page.h

@@ -36,7 +36,9 @@ struct TranscribeTask {
 class FileTranscribePage : public QWidget {
     Q_OBJECT
 public:
-    explicit FileTranscribePage(ConfigManager* configManager, QWidget* parent = nullptr);
+    explicit FileTranscribePage(ConfigManager* configManager,
+                                SenseVoiceEngine* sttEngine,
+                                QWidget* parent = nullptr);
     ~FileTranscribePage() override;
 
 private slots:

src/ui/main_window.cpp

@@ -3,6 +3,7 @@
 #include "file_transcribe_page.h"
 #include "settings_page.h"
 #include "core/voice_input_service.h"
+#include "core/sense_voice_engine.h"
 #include "app/config_manager.h"
 #include "utils/logger.h"
 
@@ -16,19 +17,21 @@ static const char* const kTag = "MainWindow";
 
 namespace impress {
 
-MainWindow::MainWindow(ConfigManager* configManager, QWidget* parent)
+MainWindow::MainWindow(ConfigManager* configManager,
+                       SenseVoiceEngine* sttEngine,
+                       QWidget* parent)
     : QMainWindow(parent)
     , configManager_(configManager)
 {
     setWindowTitle("Impress Voice Input");
     resize(1000, 700);
 
-    setupUI();
+    setupUI(sttEngine);
     setupMenuBar();
     loadStyleSheet();
 
-    // 初始化语音输入服务
+    // 初始化语音输入服务（共享全局引擎）
-    voiceInputService_ = new VoiceInputService(configManager_, this);
+    voiceInputService_ = new VoiceInputService(configManager_, sttEngine, this);
     connect(voiceInputService_, &VoiceInputService::statusChanged,
             this, [this](const QString& status) {
                 LOG_DEBUG(kTag, QString("语音输入状态: %1").arg(status));
@@ -54,11 +57,11 @@ MainWindow::MainWindow(ConfigManager* configManager, QWidget* parent)
 
 MainWindow::~MainWindow() = default;
 
-void MainWindow::setupUI() {
+void MainWindow::setupUI(SenseVoiceEngine* sttEngine) {
     tabWidget_ = new QTabWidget(this);
 
-    sttPage_ = new STTTestPage(configManager_, tabWidget_);
+    sttPage_ = new STTTestPage(configManager_, sttEngine, tabWidget_);
-    transcribePage_ = new FileTranscribePage(configManager_, tabWidget_);
+    transcribePage_ = new FileTranscribePage(configManager_, sttEngine, tabWidget_);
     settingsPage_ = new SettingsPage(configManager_, tabWidget_);
 
     tabWidget_->addTab(sttPage_, "实时语音识别");

src/ui/main_window.h

@@ -7,6 +7,7 @@
 namespace impress {
 
 class ConfigManager;
+class SenseVoiceEngine;
 class STTTestPage;
 class FileTranscribePage;
 class SettingsPage;
@@ -15,19 +16,21 @@ class VoiceInputService;
 /**
  * @brief 主窗口
  *
- * 使用 Tab 页导航管理三个功能页面。
+ * 使用 Tab 页导航管理三个功能页面，共享全局 STT 引擎。
  */
 class MainWindow : public QMainWindow {
     Q_OBJECT
 public:
-    explicit MainWindow(ConfigManager* configManager, QWidget* parent = nullptr);
+    explicit MainWindow(ConfigManager* configManager,
+                        SenseVoiceEngine* sttEngine,
+                        QWidget* parent = nullptr);
     ~MainWindow() override;
 
 protected:
     void closeEvent(QCloseEvent* event) override;
 
 private:
-    void setupUI();
+    void setupUI(SenseVoiceEngine* sttEngine);
     void setupMenuBar();
     void loadStyleSheet();
     void onVoiceInputConfigChanged();

src/ui/stt_test_page.cpp

@@ -25,10 +25,12 @@ static const char* const kTag = "STTTestPage";
 
 namespace impress {
 
-STTTestPage::STTTestPage(ConfigManager* configManager, QWidget* parent)
+STTTestPage::STTTestPage(ConfigManager* configManager,
+                         SenseVoiceEngine* sttEngine,
+                         QWidget* parent)
     : QWidget(parent)
     , configManager_(configManager)
-    , sttEngine_(new SenseVoiceEngine(this))
+    , sttEngine_(sttEngine)
     , audioCapture_(new AudioCapture(this))
     , inferenceTimer_(new QTimer(this))
 {
@@ -122,16 +124,14 @@ void STTTestPage::onToggleRecording() {
     if (isRecording_) {
         audioCapture_->stop();
         inferenceTimer_->stop();
-        sttEngine_->unloadModel();
         isRecording_ = false;
         isInferencing_ = false;
         audioBuffer_.clear();
     } else {
-        // 读取配置
+        // 检查全局模型是否已加载
-        QString modelPath = configManager_->get("stt.model_path").toString();
+        if (!sttEngine_->isLoaded()) {
-        if (modelPath.isEmpty()) {
             QMessageBox::warning(this, "提示",
-                "请先在「配置」页面设置模型路径并保存");
+                "模型尚未加载完成，请稍候再试");
             return;
         }
 
@@ -139,38 +139,17 @@ void STTTestPage::onToggleRecording() {
         sttEngine_->setDebugSaveAudio(
             configManager_->get("stt.debug_save_audio").toBool());
 
-        // 异步加载模型
-        if (!sttEngine_->isLoaded() ||
-            currentModelPath_ != modelPath) {
-            isLoadingModel_ = true;
-            statusLabel_->setText("正在加载模型，请稍候...");
-            updateUIState();
-
-            sttEngine_->loadModelAsync(modelPath,
-                configManager_->get("stt.tokens_path").toString(),
-                configManager_->get("stt.device").toString(),
-                configManager_->get("stt.num_threads").toInt());
-
-            currentModelPath_ = modelPath;
-            // 注意：startAudioCapture() 将在 onModelLoaded() 回调中调用
-        } else {
         startAudioCapture();
     }
-    }
     updateUIState();
 }
 
 void STTTestPage::onModelLoaded(const QString& modelPath) {
-    LOG_INFO(kTag, QString("模型加载成功: %1").arg(modelPath));
+    LOG_INFO(kTag, QString("全局模型加载成功: %1").arg(modelPath));
     isLoadingModel_ = false;
     statusLabel_->setText(QString("模型就绪: %1").arg(
         QFileInfo(modelPath).fileName()));
     updateUIState();
-
-    // 如果用户仍在录音状态（已切换 UI），启动采集
-    if (!isRecording_) {
-        startAudioCapture();
-    }
 }
 
 void STTTestPage::onModelLoadError(const QString& modelPath, const QString& error) {
@@ -206,8 +185,7 @@ void STTTestPage::startAudioCapture() {
     // 启动周期性推理定时器
     startInferenceTimer();
 
-    statusLabel_->setText(QString("录音中 | 模型: %1").arg(
+    statusLabel_->setText("录音中 | 模型已加载");
-        QFileInfo(currentModelPath_).fileName()));
     updateUIState();
 }
 

src/ui/stt_test_page.h

@@ -27,7 +27,9 @@ class AudioCapture;
 class STTTestPage : public QWidget {
     Q_OBJECT
 public:
-    explicit STTTestPage(ConfigManager* configManager, QWidget* parent = nullptr);
+    explicit STTTestPage(ConfigManager* configManager,
+                         SenseVoiceEngine* sttEngine,
+                         QWidget* parent = nullptr);
     ~STTTestPage() override;
 
 private slots:
@@ -64,7 +66,6 @@ private:
     bool isInferencing_ = false;
     int audioSampleRate_ = 16000;
     std::vector<float> audioBuffer_;
-    QString currentModelPath_;
 };
 
 } // namespace impress