poc: Load snapshot through the options dialog

This is a quick and dirty POC to showcase and test the load snapshot functionality. This is by no means meant to be a robust approach...

Author: D33r-Gee

src/qt/CMakeLists.txt

@@ -116,6 +116,8 @@ add_library(bitcoinqt STATIC EXCLUDE_FROM_ALL
   qvaluecombobox.h
   rpcconsole.cpp
   rpcconsole.h
+  snapshotmodel.cpp
+  snapshotmodel.h
   splashscreen.cpp
   splashscreen.h
   trafficgraphwidget.cpp

src/qt/optionsdialog.cpp

@@ -12,6 +12,7 @@
 #include <qt/guiconstants.h>
 #include <qt/guiutil.h>
 #include <qt/optionsmodel.h>
+#include <qt/snapshotmodel.h>
 
 #include <common/system.h>
 #include <interfaces/node.h>
@@ -25,6 +26,7 @@
 #include <QApplication>
 #include <QDataWidgetMapper>
 #include <QDir>
+#include <QFileDialog>
 #include <QFontDialog>
 #include <QIntValidator>
 #include <QLocale>
@@ -121,6 +123,10 @@ OptionsDialog::OptionsDialog(QWidget* parent, bool enableWallet)
     connect(ui->connectSocksTor, &QPushButton::toggled, ui->proxyPortTor, &QWidget::setEnabled);
     connect(ui->connectSocksTor, &QPushButton::toggled, this, &OptionsDialog::updateProxyValidationState);
 
+    QPushButton* loadSnapshotButton = new QPushButton(tr("Load Snapshot..."), this);
+    ui->verticalLayout_Main->insertWidget(ui->verticalLayout_Main->indexOf(ui->enableServer) + 1, loadSnapshotButton);
+    connect(loadSnapshotButton, &QPushButton::clicked, this, &OptionsDialog::on_loadSnapshotButton_clicked);
+
     /* Window elements init */
 #ifdef Q_OS_MACOS
     /* remove Window tab on Mac */
@@ -400,6 +406,34 @@ void OptionsDialog::on_showTrayIcon_stateChanged(int state)
     }
 }
 
+void OptionsDialog::on_loadSnapshotButton_clicked()
+{
+    QString snapshotFile = QFileDialog::getOpenFileName(this,
+        tr("Select Snapshot File"), "",
+        tr("Bitcoin Snapshot Files (*.dat);;All Files (*)"));
+
+    if (snapshotFile.isEmpty())
+        return;
+
+    QMessageBox::StandardButton reply = QMessageBox::question(this,
+        tr("Load Snapshot"),
+        tr("Loading a snapshot will require restarting Bitcoin. The current blockchain data will be replaced with the snapshot data. Are you sure you want to proceed?"),
+        QMessageBox::Yes|QMessageBox::No);
+
+    if (reply == QMessageBox::Yes) {
+        SnapshotModel snapshotModel(model->node(), snapshotFile);
+        if (snapshotModel.processPath()) {
+            QMessageBox::information(this,
+                tr("Snapshot loaded successfully"),
+                tr("The snapshot has been loaded successfully. You can now start the client with the new snapshot."));
+        } else {
+            QMessageBox::critical(this,
+                tr("Error"),
+                tr("Failed to load the snapshot. Please ensure the file is a valid snapshot and try again."));
+        }
+    }
+}
+
 void OptionsDialog::togglePruneWarning(bool enabled)
 {
     ui->pruneWarning->setVisible(!ui->pruneWarning->isVisible());

src/qt/optionsdialog.h

@@ -58,6 +58,8 @@ private Q_SLOTS:
     void on_openBitcoinConfButton_clicked();
     void on_okButton_clicked();
     void on_cancelButton_clicked();
+    void on_loadSnapshotButton_clicked();
+
 
     void on_showTrayIcon_stateChanged(int state);
 

src/qt/snapshotmodel.cpp

@@ -0,0 +1,45 @@
+// Copyright (c) 2024 - present The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <qt/snapshotmodel.h>
+
+#include <interfaces/node.h>
+#include <node/context.h>
+#include <node/utxo_snapshot.h>
+#include <clientversion.h>
+#include <validation.h>
+#include <util/fs.h>
+#include <util/fs_helpers.h>
+
+SnapshotModel::SnapshotModel(interfaces::Node& node, QString path)
+    : m_node(node), m_path(path) {}
+
+bool SnapshotModel::processPath()
+{
+    ChainstateManager& chainman = *m_node.context()->chainman;
+    const fs::path snapshot_path = fs::u8path(m_path.toStdString());
+    if (!fs::exists(snapshot_path)) {
+        return false;
+    }
+
+    FILE* snapshot_file{fsbridge::fopen(snapshot_path, "rb")};
+    AutoFile coins_file{snapshot_file};
+    if (coins_file.IsNull()) {
+        return false;
+    }
+
+    node::SnapshotMetadata metadata{chainman.GetParams().MessageStart()};
+    try {
+        coins_file >> metadata;
+    } catch (const std::exception& e) {
+        return false;
+    }
+
+    bool result = m_node.loadSnapshot(coins_file, metadata, false);
+    if (!result) {
+        return false;
+    }
+
+    return true;
+}

src/qt/snapshotmodel.h

@@ -0,0 +1,28 @@
+// Copyright (c) 2024 - present The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_QT_SNAPSHOTMODEL_H
+#define BITCOIN_QT_SNAPSHOTMODEL_H
+
+#include <QObject>
+#include <interfaces/node.h>
+#include <node/context.h>
+#include <node/utxo_snapshot.h>
+
+/** Model for snapshot operations. */
+class SnapshotModel : public QObject
+{
+    Q_OBJECT
+
+public:
+    SnapshotModel(interfaces::Node& node, QString path);
+
+    bool processPath();
+
+private:
+    interfaces::Node& m_node;
+    QString m_path;
+};
+
+#endif // BITCOIN_QT_SNAPSHOTMODEL_H