support pruning of new databases

main.qml

@@ -724,7 +724,7 @@ ApplicationWindow {
 
         const noSync = appWindow.walletMode === 0;
         const bootstrapNodeAddress = persistentSettings.walletMode < 2 ? "auto" : persistentSettings.bootstrapNodeAddress
-        daemonManager.start(flags, persistentSettings.nettype, persistentSettings.blockchainDataDir, bootstrapNodeAddress, noSync);
+        daemonManager.start(flags, persistentSettings.nettype, persistentSettings.blockchainDataDir, bootstrapNodeAddress, noSync, persistentSettings.pruneBlockchain);
     }
 
     function stopDaemon(callback, splash){
@@ -1410,6 +1410,7 @@ ApplicationWindow {
         property bool checkForUpdates: true
         property bool autosave: true
         property int autosaveMinutes: 10
+        property bool pruneBlockchain: false
 
         property bool fiatPriceEnabled: false
         property bool fiatPriceToggle: false

src/daemon/DaemonManager.cpp

@@ -27,6 +27,7 @@
 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "DaemonManager.h"
+#include "common/util.h"
 #include <QElapsedTimer>
 #include <QFile>
 #include <QMutexLocker>
@@ -47,7 +48,7 @@ namespace {
     static const int DAEMON_START_TIMEOUT_SECONDS = 120;
 }
 
-bool DaemonManager::start(const QString &flags, NetworkType::Type nettype, const QString &dataDir, const QString &bootstrapNodeAddress, bool noSync /* = false*/)
+bool DaemonManager::start(const QString &flags, NetworkType::Type nettype, const QString &dataDir, const QString &bootstrapNodeAddress, bool noSync /* = false*/, bool pruneBlockchain /* = false*/)
 {
     if (!QFileInfo(m_monerod).isFile())
     {
@@ -85,6 +86,12 @@ bool DaemonManager::start(const QString &flags, NetworkType::Type nettype, const
         arguments << "--bootstrap-daemon-address" << bootstrapNodeAddress;
     }
 
+    if (pruneBlockchain) {
+        if (!checkLmdbExists(dataDir)) { // check that DB has not already been created
+            arguments << "--prune-blockchain";
+        }
+    }
+
     if (noSync) {
         arguments << "--no-sync";
     }
@@ -322,6 +329,13 @@ QVariantMap DaemonManager::validateDataDir(const QString &dataDir) const
     return result;
 }
 
+bool DaemonManager::checkLmdbExists(QString datadir) {
+    if (datadir.isEmpty() || datadir.isNull()) {
+        datadir = QString::fromStdString(tools::get_default_data_dir());
+    }
+    return validateDataDir(datadir).value("lmdbExists").value<bool>();
+}
+
 DaemonManager::DaemonManager(QObject *parent)
     : QObject(parent)
     , m_scheduler(this)

src/daemon/DaemonManager.h

@@ -47,7 +47,7 @@ public:
     explicit DaemonManager(QObject *parent = 0);
     ~DaemonManager();
 
-    Q_INVOKABLE bool start(const QString &flags, NetworkType::Type nettype, const QString &dataDir = "", const QString &bootstrapNodeAddress = "", bool noSync = false);
+    Q_INVOKABLE bool start(const QString &flags, NetworkType::Type nettype, const QString &dataDir = "", const QString &bootstrapNodeAddress = "", bool noSync = false, bool pruneBlockchain = false);
     Q_INVOKABLE void stopAsync(NetworkType::Type nettype, const QJSValue& callback);
 
     Q_INVOKABLE bool noSync() const noexcept;
@@ -57,6 +57,7 @@ public:
     Q_INVOKABLE void sendCommandAsync(const QStringList &cmd, NetworkType::Type nettype, const QJSValue& callback) const;
     Q_INVOKABLE void exit();
     Q_INVOKABLE QVariantMap validateDataDir(const QString &dataDir) const;
+    Q_INVOKABLE bool checkLmdbExists(QString datadir);
 
 private:
 

wizard/WizardDaemonSettings.qml

@@ -94,6 +94,28 @@ ColumnLayout {
             }
         }
 
+        RowLayout {
+            id: pruningOptionRow
+            MoneroComponents.CheckBox {
+                id: pruneBlockchainCheckBox
+                checked: !existingDbWarning.visible ? persistentSettings.pruneBlockchain : false
+                enabled: !existingDbWarning.visible
+                onClicked: {
+                    persistentSettings.pruneBlockchain =  !persistentSettings.pruneBlockchain
+                    this.checked = persistentSettings.pruneBlockchain
+                }
+                text: qsTr("Prune blockchain") + translationManager.emptyString
+            }
+
+            Text {
+                id: existingDbWarning
+                text: "A blockchain database already exists here. Select a new location to start a pruned node"
+                visible: daemonManager ? daemonManager.checkLmdbExists(blockchainFolder.text) : false
+                color: MoneroComponents.Style.defaultFontColor
+                font.family: MoneroComponents.Style.fontRegular.name
+            }
+        }
+
         ColumnLayout{
             Layout.topMargin: 6
             spacing: 0

wizard/WizardModeSelection.qml

@@ -119,6 +119,7 @@ Rectangle {
 
                 onMenuClicked: {
                     if(appWindow.persistentSettings.nettype == 0){
+                        appWindow.persistentSettings.pruneBlockchain = true;
                         applyWalletMode(1, 'wizardModeBootstrap');
                     }
                 }
@@ -139,6 +140,7 @@ Rectangle {
                 imageIcon: "qrc:///images/local-node-full.png"
 
                 onMenuClicked: {
+                    appWindow.persistentSettings.pruneBlockchain = false; // can be toggled on next page
                     applyWalletMode(2, 'wizardHome');
                 }
             }