cpp: Implement snapshot load progress notifications

- Added a new signal for snapshot load progress in the UI interface.
- Updated the notifications interface to include a method for reporting snapshot loading progress.
- Enhanced the ChainstateManager to report progress during snapshot loading.
- Implemented the necessary handler in the kernel notifications to relay progress updates.

This change improves user feedback during the snapshot loading process.

Author: D33r-Gee

src/interfaces/node.h

@@ -237,6 +237,10 @@ class Node
     using ShowProgressFn = std::function<void(const std::string& title, int progress, bool resume_possible)>;
     virtual std::unique_ptr<Handler> handleShowProgress(ShowProgressFn fn) = 0;
 
+    //! Register handler for snapshot load progress.
+    using SnapshotLoadProgressFn = std::function<void(double progress)>;
+    virtual std::unique_ptr<Handler> handleSnapshotLoadProgress(SnapshotLoadProgressFn fn) = 0;
+
     //! Register handler for wallet loader constructed messages.
     using InitWalletFn = std::function<void()>;
     virtual std::unique_ptr<Handler> handleInitWallet(InitWalletFn fn) = 0;

src/kernel/notifications_interface.h

@@ -40,6 +40,7 @@ class Notifications
     [[nodiscard]] virtual InterruptResult blockTip(SynchronizationState state, CBlockIndex& index, double verification_progress) { return {}; }
     virtual void headerTip(SynchronizationState state, int64_t height, int64_t timestamp, bool presync) {}
     virtual void progress(const bilingual_str& title, int progress_percent, bool resume_possible) {}
+    virtual void snapshotLoadProgress(double progress) {}
     virtual void warningSet(Warning id, const bilingual_str& message) {}
     virtual void warningUnset(Warning id) {}
 

src/node/interface_ui.cpp

@@ -23,6 +23,7 @@ struct UISignals {
     boost::signals2::signal<CClientUIInterface::NotifyNetworkActiveChangedSig> NotifyNetworkActiveChanged;
     boost::signals2::signal<CClientUIInterface::NotifyAlertChangedSig> NotifyAlertChanged;
     boost::signals2::signal<CClientUIInterface::ShowProgressSig> ShowProgress;
+    boost::signals2::signal<CClientUIInterface::SnapshotLoadProgressSig> SnapshotLoadProgress;
     boost::signals2::signal<CClientUIInterface::NotifyBlockTipSig> NotifyBlockTip;
     boost::signals2::signal<CClientUIInterface::NotifyHeaderTipSig> NotifyHeaderTip;
     boost::signals2::signal<CClientUIInterface::BannedListChangedSig> BannedListChanged;
@@ -46,6 +47,7 @@ ADD_SIGNALS_IMPL_WRAPPER(ShowProgress);
 ADD_SIGNALS_IMPL_WRAPPER(NotifyBlockTip);
 ADD_SIGNALS_IMPL_WRAPPER(NotifyHeaderTip);
 ADD_SIGNALS_IMPL_WRAPPER(BannedListChanged);
+ADD_SIGNALS_IMPL_WRAPPER(SnapshotLoadProgress);
 
 bool CClientUIInterface::ThreadSafeMessageBox(const bilingual_str& message, const std::string& caption, unsigned int style) { return g_ui_signals.ThreadSafeMessageBox(message, caption, style).value_or(false);}
 bool CClientUIInterface::ThreadSafeQuestion(const bilingual_str& message, const std::string& non_interactive_message, const std::string& caption, unsigned int style) { return g_ui_signals.ThreadSafeQuestion(message, non_interactive_message, caption, style).value_or(false);}
@@ -55,6 +57,7 @@ void CClientUIInterface::NotifyNumConnectionsChanged(int newNumConnections) { re
 void CClientUIInterface::NotifyNetworkActiveChanged(bool networkActive) { return g_ui_signals.NotifyNetworkActiveChanged(networkActive); }
 void CClientUIInterface::NotifyAlertChanged() { return g_ui_signals.NotifyAlertChanged(); }
 void CClientUIInterface::ShowProgress(const std::string& title, int nProgress, bool resume_possible) { return g_ui_signals.ShowProgress(title, nProgress, resume_possible); }
+void CClientUIInterface::SnapshotLoadProgress(double progress) { return g_ui_signals.SnapshotLoadProgress(progress); }
 void CClientUIInterface::NotifyBlockTip(SynchronizationState s, const CBlockIndex& block, double verification_progress) { return g_ui_signals.NotifyBlockTip(s, block, verification_progress); }
 void CClientUIInterface::NotifyHeaderTip(SynchronizationState s, int64_t height, int64_t timestamp, bool presync) { return g_ui_signals.NotifyHeaderTip(s, height, timestamp, presync); }
 void CClientUIInterface::BannedListChanged() { return g_ui_signals.BannedListChanged(); }

src/node/interface_ui.h

@@ -102,6 +102,9 @@ class CClientUIInterface
      */
     ADD_SIGNALS_DECL_WRAPPER(ShowProgress, void, const std::string& title, int nProgress, bool resume_possible);
 
+    /** Snapshot load progress. */
+    ADD_SIGNALS_DECL_WRAPPER(SnapshotLoadProgress, void, double progress);
+
     /** New block has been accepted */
     ADD_SIGNALS_DECL_WRAPPER(NotifyBlockTip, void, SynchronizationState, const CBlockIndex& block, double verification_progress);
 

src/node/interfaces.cpp

@@ -391,6 +391,10 @@ class NodeImpl : public Node
     {
         return MakeSignalHandler(::uiInterface.ShowProgress_connect(fn));
     }
+    std::unique_ptr<Handler> handleSnapshotLoadProgress(SnapshotLoadProgressFn fn) override
+    {
+        return MakeSignalHandler(::uiInterface.SnapshotLoadProgress_connect(fn));
+    }
     std::unique_ptr<Handler> handleInitWallet(InitWalletFn fn) override
     {
         return MakeSignalHandler(::uiInterface.InitWallet_connect(fn));

src/node/kernel_notifications.cpp

@@ -77,6 +77,11 @@ void KernelNotifications::progress(const bilingual_str& title, int progress_perc
     uiInterface.ShowProgress(title.translated, progress_percent, resume_possible);
 }
 
+void KernelNotifications::snapshotLoadProgress(double progress)
+{
+    uiInterface.SnapshotLoadProgress(progress);
+}
+
 void KernelNotifications::warningSet(kernel::Warning id, const bilingual_str& message)
 {
     if (m_warnings.Set(id, message)) {

src/node/kernel_notifications.h

@@ -41,6 +41,8 @@ class KernelNotifications : public kernel::Notifications
 
     void progress(const bilingual_str& title, int progress_percent, bool resume_possible) override;
 
+    void snapshotLoadProgress(double progress) override;
+
     void warningSet(kernel::Warning id, const bilingual_str& message) override;
 
     void warningUnset(kernel::Warning id) override;

src/validation.cpp

@@ -5980,6 +5980,10 @@ util::Result<void> ChainstateManager::PopulateAndValidateSnapshot(
                 --coins_left;
                 ++coins_processed;
 
+                // Show Snapshot Loading progress
+                double progress = static_cast<double>(coins_processed) / static_cast<double>(coins_count);
+                GetNotifications().snapshotLoadProgress(progress);
+
                 if (coins_processed % 1000000 == 0) {
                     LogInfo("[snapshot] %d coins loaded (%.2f%%, %.2f MB)",
                         coins_processed,