Implement restore database in the GUI

src/calibre/gui2/actions/choose_library.py

@@ -16,7 +16,6 @@ from calibre.utils.config import prefs
 from calibre.gui2 import gprefs, warning_dialog, Dispatcher, error_dialog, \
     question_dialog, info_dialog
 from calibre.gui2.actions import InterfaceAction
-from calibre.gui2.dialogs.check_library import CheckLibraryDialog, DBCheck
 
 class LibraryUsageStats(object): # {{{
 
@@ -139,6 +138,12 @@ class ChooseLibraryAction(InterfaceAction):
                                       None, None), attr='action_check_library')
         ac.triggered.connect(self.check_library, type=Qt.QueuedConnection)
         self.maintenance_menu.addAction(ac)
+        ac = self.create_action(spec=(_('Restore database'), 'lt.png',
+                                      None, None),
+                                      attr='action_restore_database')
+        ac.triggered.connect(self.restore_database, type=Qt.QueuedConnection)
+        self.maintenance_menu.addAction(ac)
+
         self.choose_menu.addMenu(self.maintenance_menu)
 
     def pick_random(self, *args):
@@ -267,7 +272,17 @@ class ChooseLibraryAction(InterfaceAction):
             _('Metadata will be backed up while calibre is running, at the '
               'rate of approximately 1 book every three seconds.'), show=True)
 
+    def restore_database(self):
+        from calibre.gui2.dialogs.restore_library import restore_database
+        m = self.gui.library_view.model()
+        m.stop_metadata_backup()
+        db = m.db
+        db.prefs.disable_setting = True
+        if restore_database(db, self.gui):
+            self.gui.library_moved(db.library_path, call_close=False)
+
     def check_library(self):
+        from calibre.gui2.dialogs.check_library import CheckLibraryDialog, DBCheck
         self.gui.library_view.save_state()
         m = self.gui.library_view.model()
         m.stop_metadata_backup()

src/calibre/gui2/dialogs/restore_library.py

@@ -0,0 +1,115 @@
+#!/usr/bin/env python
+# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+
+__license__   = 'GPL v3'
+__copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
+__docformat__ = 'restructuredtext en'
+
+from PyQt4.Qt import QDialog, QLabel, QVBoxLayout, QDialogButtonBox, \
+        QProgressBar, QSize, QTimer, pyqtSignal, Qt
+
+from calibre.library.restore import Restore
+from calibre.gui2 import error_dialog, question_dialog, warning_dialog, \
+    info_dialog
+
+class DBRestore(QDialog):
+
+    update_signal = pyqtSignal(object, object)
+
+    def __init__(self, parent, library_path):
+        QDialog.__init__(self, parent)
+        self.l = QVBoxLayout()
+        self.setLayout(self.l)
+        self.l1 = QLabel('<b>'+_('Restoring database from backups, do not'
+            ' interrupt, this will happen in two stages')+'...')
+        self.setWindowTitle(_('Restoring database'))
+        self.l.addWidget(self.l1)
+        self.pb = QProgressBar(self)
+        self.l.addWidget(self.pb)
+        self.pb.setMaximum(0)
+        self.pb.setMinimum(0)
+        self.msg = QLabel('')
+        self.l.addWidget(self.msg)
+        self.msg.setWordWrap(True)
+        self.bb = QDialogButtonBox(QDialogButtonBox.Cancel)
+        self.l.addWidget(self.bb)
+        self.bb.rejected.connect(self.reject)
+        self.resize(self.sizeHint() + QSize(100, 50))
+        self.error = None
+        self.rejected = False
+        self.library_path = library_path
+        self.update_signal.connect(self.do_update, type=Qt.QueuedConnection)
+
+        self.restorer = Restore(library_path, self)
+        self.restorer.daemon = True
+
+        # Give the metadata backup thread time to stop
+        QTimer.singleShot(2000, self.start)
+
+
+    def start(self):
+        self.restorer.start()
+        QTimer.singleShot(10, self.update)
+
+    def reject(self):
+        self.rejected = True
+        self.restorer.progress_callback = lambda x, y: x
+        QDialog.rejecet(self)
+
+    def update(self):
+        if self.restorer.is_alive():
+            QTimer.singleShot(10, self.update)
+        else:
+            self.restorer.progress_callback = lambda x, y: x
+            self.accept()
+
+    def __call__(self, msg, step):
+        self.update_signal.emit(msg, step)
+
+    def do_update(self, msg, step):
+        if msg is None:
+            self.pb.setMaximum(step)
+        else:
+            self.msg.setText(msg)
+            self.pb.setValue(step)
+
+
+def restore_database(db, parent=None):
+    if not question_dialog(parent, _('Are you sure?'), '<p>'+
+            _('Your list of books, with all their metadata is '
+                'stored in a single file, called a database. '
+                'In addition, metadata for each individual '
+                'book is stored in that books\' folder, as '
+                'a backup.'
+                '<p>This operation will rebuild '
+                'the database from the individual book '
+                'metadata. This is useful if the '
+                'database has been corrupted and you get a '
+                'blank list of books. Note that restoring only '
+                'restores books, not any settings stored in the '
+                'database, or any custom recipes.'
+                '<p>Do you want to restore the database?')):
+        return False
+    db.conn.close()
+    d = DBRestore(parent, db.library_path)
+    d.exec_()
+    r = d.restorer
+    d.restorer = None
+    if d.rejected:
+        return True
+    if r.tb is not None:
+        error_dialog(parent, _('Failed'),
+        _('Restoring database failed, click Show details to see details'),
+        det_msg=r.tb, show=True)
+    else:
+        if r.errors_occurred:
+            warning_dialog(parent, _('Success'),
+                    _('Restoring the database succeeded with some warnings',
+                        ' click Show details to see the details.'),
+                    det_msg=r.report, show=True)
+        else:
+            info_dialog(parent, _('Success'),
+                    _('Restoring database was successful'), show=True,
+                    show_copy_button=False)
+    return True
+