def update(self, doc, process=None):
        if process is None:
            pk = 'id'
            id = doc.id
            doc.synced = False
            set = doc
        elif process == UPDATE_PROCESS:
            if self.db.docs.find({'sid': doc.sid}).count() == 0:
                return self.insert(doc, synced=True)
            pk = 'sid'
            id = doc.sid
            doc.synced = not doc.merged() # must be commited if was merged
            doc.merged(False)
            set = {'tid': doc.tid, 'data': doc.data, 'user': doc.user,
                   'public': doc.public, 'synced': doc.synced}
        elif process == COMMIT_PROCESS:
            pk = 'id'
            id = doc.id
            doc.synced = True
            set = {'sid': doc.sid, 'tid': doc.tid, 'synced': doc.synced}
        else:
            raise DatabaseException('Incorrect update process')

        try:
            rs = self.db.docs.update({pk: id}, {'$set': set}, safe=True)
            assert rs['n'] == 1
        except Exception as e:
            raise DatabaseException(e)
        return doc
def toggle_comment(self):
        "Toggle the selected comment tree between visible and hidden"

        current_index = self.nav.absolute_index
        self.content.toggle(current_index)

        # This logic handles a display edge case after a comment toggle. We
        # want to make sure that when we re-draw the page, the cursor stays at
        # its current absolute position on the screen. In order to do this,
        # apply a fixed offset if, while inverted, we either try to hide the
        # bottom comment or toggle any of the middle comments.
        if self.nav.inverted:
            data = self.content.get(current_index)
            if data['hidden'] or self.nav.cursor_index != 0:
                window = self._subwindows[-1][0]
                n_rows, _ = window.getmaxyx()
                self.nav.flip(len(self._subwindows) - 1)
                self.nav.top_item_height = n_rows